Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
532 AM AST Fri Feb 9 2024

.SYNOPSIS...
Issued at 522 AM AST Fri Feb 9 2024

Stable weather conditions will persist during the next several
days as a broad high pressure dominates across the Atlantic and a
drier airmass is establishing over Puerto Rico and the U.S. Virgin
Islands. Isolated shower activity cannot be ruled out of the
forecast due to shallow moisture and light winds, mainly during
the morning hours over the eastern PR. A warming trend is
anticipated from Tuesday onwards as winds will shift from the
southeast and moisture will increase from the south. Northerly
swells arriving over the next several days will further
deteriorate marine and coastal conditions for the Atlantic waters
and local passages through early next week.


&&

.SHORT TERM...Today through Sunday

Variable weather conditions prevailed during the night hours, with
isolated to moderate showers affecting northern and interior
sections of Puerto Rico as well as the local waters. Shower activity
was frequent. However, rainfall accumulations remained minimal;
according to the Radar Doppler estimates, the highest occurred
across Manati and Naguabo, with almost 3/4 of an inch. Overnight
temperatures ranged from the low to mid-70s along the coastal areas
and in the low to mid-60s across the mountain sections.

Today, a variable weather pattern is expected as a pocket of
cloudiness and shallow moisture stream across the northern coastal
areas. The shower activity will be shallow, and no significant
rainfall accumulations anticipated for the rest of the morning,
but ponding of water in low-lying areas and urban sections cannot
be ruled out. As the day progresses, a much drier airmass with
Precipitable water around 0.80 inches (GOES Satellite-derived
Imagery) will move into the region, leading to a more stable
weather pattern with some clouds and localized showers in the
afternoon across the interior and southern areas due to the wind
direction.

By Saturday into Sunday, a broad mid- to upper-level ridge across
the western Atlantic extending into the Caribbean will be the
dominant feature, resulting in a strong trade wind cap with warmer
temperatures at 500 MB and drier air aloft. A similar pattern will
be reflected at the surface, with the influence of a broad surface
high-pressure extending from the Western Atlantic into the central
Atlantic. This surface feature will induce a variation in wind
direction, persisting from the northeast early on Saturday and
veering on Sunday, becoming more easterly. According to the model
guidance, precipitable water values will drop two standard
deviations from the normal climatological values on Saturday and
slightly increase on Sunday. Given the expected weather, the islands
can expect shower activity resulting from local and diurnal effects
and available moisture. Although showers are expected, widespread
shower activity is not anticipated.

&&

.LONG TERM...Monday through Friday...

Weather models agree that a broad surface high pressure centered
over the Atlantic will continue to dominate weather conditions in
our region for the beginning of this work week. At the mid-levels,
a similar pattern is expected, with models suggesting a broad
mid-level ridge extending from the western Atlantic to the
Caribbean. As a result, winds will remain relatively light from
the northeast promoting temperatures to remain near normal to
slightly below normal on Monday across Puerto Rico and the U.S.
Virgin Islands. It is forecast that the precipitable water content
in the atmosphere will remain around 1 inch, which is below
normal, however, some isolated shower activity cannot be ruled out
from the forecast due to shallow humidity and light winds, mainly
during the morning hours over eastern PR, but under this pattern
the rain should be very limited.

At the same time, a low pressure along with its associated cold
front will be moving over the Southeastern U.S. towards the
western Atlantic which will weaken and push the high pressure over
the Atlantic towards the east. That pattern will change our wind
flow from the southeast. Therefore, from Tuesday onwards we are
anticipating a warming trend in temperatures and an increase in
tropical humidity across the forecast area. Expect temperatures to
be around 3 to 5 degrees above normal for this time of the year
and PWAT values could be ranging closer to normal; ~1.5 inches. As
a result, around Tuesday afternoon into Wednesday, we can expect
the return of a more variable weather pattern with isolated to
scattered showers gradually developing throughout the day.

By the latter part of the week, the weakening cold front will be
located well north of our region, and patches of drier air will
settle over our region. It will continue to be warmer-than-normal,
and diurnal/local effects will promote a pattern of passing rain
showers across eastern Puerto Rico and the U.S. Virgin Islands,
followed by afternoon convection primarily across the interior to
the western section of Puerto Rico with the easterly wind flow. We
will continue to monitor closely for any changes.


&&

.AVIATION...
(12Z TAFS)
Issued at 522 AM AST Fri Feb 9 2024

VFR conditions will prevail across all the TAF sites as a much
drier airmass moves into the region, limiting cloudiness and
showers. But until 09/15Z, VCSH to -RA will persist across TJSJ
and TJPS. Winds will continue from the N, increasing to 15 knots
at 09/15Z, with gusty winds and sea breeze variations. Winds will
turn more from the N-NE at 10/03Z.


&&

.MARINE...
Issued at 522 AM AST Fri Feb 9 2024

Moderate to fresh northerly wind flow will be present across the
local waters as a broad surface high pressure dominates across the
western Atlantic. Winds continue to gradually veer over the next
few days until becoming easterly by the weekend. Pulses of
northerly swells will spread across the local waters into the
weekend, creating hazardous marine and coastal conditions for the
Atlantic waters and local passages through early next week.
Therefore, Small Craft Advisories will remain in effect due to
seas building between 7 and 10 feet during the next few days.
Please refer to the latest Marine Weather Message (MWWSJU) for
additional details.


&&

.BEACH FORECAST...
Issued at 522 AM AST Fri Feb 9 2024

Pulses of long period swells will cause large breaking wave action
across west, north, and eastern beaches of Puerto Rico, Culebra,
and the northern U.S. Virgin Islands through at least early next
week. Therefore, a High Rip Current Risk and a High Surf Advisory
are in effect due to dangerous large breaking waves and life-
threatening rip currents. Please refer to the latest Coastal
Hazard Message and Surf Zone Forecast (SRFSJU) for detailed
information (CFWSJU). A larger northerly swell with longer wave
periods is expected on Sunday and Monday.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Sat Feb 10 2024

.SYNOPSIS...

Generally fair weather conditions with a mixture of clouds and
sunshine with occasional rains will persist this weekend. Showery
weather is forecast for Monday and Tuesday as a modified old
frontal boundary moves across the region.

Northerly swells will maintain deteriorated marine and coastal
conditions for the Atlantic waters and local passages through
early next week. Surf Heights are rising across northern exposed
coastlines, becoming in excess of 10 feet tomorrow, which will
last through Tuesday. Exercise caution when visiting the beach
these upcoming days due to these conditions.

&&

.SHORT TERM...Today through Monday...

A subtropical surface high-pressure building across the Atlantic
Ocean to the north promotes trade winds between 10 and 15 mph
overnight. Those trade winds brought patches of stratified clouds
and showers across the northern windward sections of PR and the U.S.
Virgin Islands, while the rest of the leeward sections enjoyed
mostly clear skies with little or no rain. The tropical winter low
temperatures are finally here, and the thermometer dropped to the
low 70s along the coast and into the low 60s or upper 50s in
mountains and valleys.

A vertically stacked high-pressure system will promote an advective
pattern with stable conditions with occasional passing trade showers
this weekend and early next week. As a result, the northern and
eastern windward sections of Puerto Rico and the U.S. Virgin Islands
can expect a mixture of clouds and sunshine with stratified clouds
moving by with occasional rains, a typical winter weather pattern
for the islands. Additionally, breezy conditions and cooler-than-
normal temperatures variations are likely. We expect a similar
weather pattern on Sunday. Although a stable atmosphere with below-
normal moisture will be present, the trade wind showers will push
fragments of moisture with shallow clouds that sometimes cause rainy
conditions.

On Monday, the surface high pressure will move into the Central
Atlantic, pushing the remnants of a modified old frontal boundary
that will increase the available moisture. Thus, it may result in
showery weather from Monday afternoon to the evening hours.


&&

.LONG TERM... Tuesday through Saturday....

Mostly fair weather conditions will prevail during the long term
period as a mid to upper-level ridge holds over the eastern
Caribbean and precipitable water values remain quite low. During the
beginning of the period on Tuesday, a surface high northeast of the
region will begin to direct a southeasterly surface wind flow across
the islands, bringing in a a patch of moist air through Tuesday
afternoon. This may bring some passing showers across windward
sections and some light convection across northwestern PR. However
by Wednesday the arrival of dry air should eliminate any potential
for showers throughout the day.

Wind speed will begin to lighten on Wednesday as the surface ridge
moved further into the central Atlantic. The pattern of lighter
wind and little to no rain should last until Friday when a robust
surface ridge moving north of the region will accelerate the
trades and advect a relatively moist airmass across the islands.
This should yield a seasonal pattern of passing windward showers
with afternoon convective development, however nothing significant
is expected as pronounced ridging still remains across the mid to
upper-levels, stabilizing local conditions.


&&

.AVIATION...
(06Z TAFS)

VFR conditions will persist through the forecast periods. Clouds
will arrive from time to time across the islands and may result in
SHRA/-SHRA across JSJ/IST/ISX/JBQ at times. Winds will persist
mainly from the NE at 5-10 kt through 10/13z, increasing at around
15 kt with higher gusts up to 25 kt with sea breeze variations.

&&

.MARINE...

A broad surface high pressure is developing over the western
Atlantic as a strong low pressure moves northeast through the central
Atlantic. The low pressure system will send consistent pulses of
northerly swell into the local area, creating hazardous marine and
coastal conditions through at least Tuesday. As high pressure
stretches north of our area, northeast winds will remain moderate to
fresh through today, then turn east by Sunday into early next
week.

&&

.BEACH FORECAST...

Strong northerly swells and windy conditions will mainly effect
northern, eastern, and western beaches over the next few days.
Breaking waves in excess of 10 feet are expected across northern
exposed beaches of Puerto Rico starting tomorrow, therefore there
is a High Surf Advisory starting tomorrow lasting until Tuesday,
with a High Risk of Rip Currents remaining in place alongside
this. Beaches of southern Puerto Rico remain the calmest during
this time, however expect windy conditions, especially during the
afternoon hours.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
435 AM AST Sun Feb 11 2024


.SYNOPSIS...

Generally fair weather conditions will persist today due to a
broad high pressure over the Atlantic and a dry air mass over the
region. Isolated passing showers are forecast but with no
significant accumulations. An increase in moisture is forecast for
late Monday and Tuesday as remnants from a past frontal boundary
reach the region.

Northerly swells are promoting deteriorated marine and coastal
conditions. Small Craft Advisories are in effect for the Atlantic
waters and local passages through at least Tuesday afternoon.
Surf Heights are in excess of 10 feet or higher across northern
exposed coastlines. High Surf Advisories and High Risk of Rip
Currents are in effect through Tuesday.

&&

.SHORT-TERM...Today through Tuesday...

Hazardous breaking waves are battering the Atlantic Coastline from
Rincon to Fajardo, Culebra, and the U.S. Virgin Islands, creating
life-threatening coastal conditions. A subtropical surface high
north of the islands and moving eastward across the Atlantic
promoted northeasterly winds between 10 and 15 mph overnight.
Despite the calm weather conditions with little or no rain across
most PR and the U.S. Virgin Islands, the trade winds brought
fragmented moisture, creating cloudy skies and shallow rains across
the windward locations. In contrast, the remaining PR's leeward
sections enjoyed mostly clear skies without rain. Once again, the
tropical winter low temperatures caused the thermometer to drop to
the low 70s along the coast and from the low 60s to mid-50s in
mountains and valleys.

A High Surf Advisory is in effect for the Atlantic coastline of PR
from Rincon to Fajardo, Culebra, and the U.S. Virgin Islands through
at least Tuesday.

A mid to upper-level high-pressure ridge aloft promotes subsidence
due to dry air intrusion above the strong trade wind cap at around
850 MB; the moisture content is trapped below this level. Last
night, JSJ-sounding data and satellite-derived data showed
precipitable water content between 0.85 and 1.05 inches of water,
which is well below normal for February. Additionally, the east-to-
east-northeast winds promoted by the subtropical surface high will
continue to push fragments of clouds and moisture into the Northeast
Caribbean to affect PR and the USVI. This weather pattern will
support a stable atmosphere with pleasant tropical winter
temperatures and the arrival of occasional clouds and rain showers,
especially during the night.

Model guidance is drying out the low-level moisture, and Monday
looks drier than yesterday's model guidance. However, the typical
occasional periods of cloudy skies with showery weather will remain
possible for Monday as the surface high pressure moves further into
the Central Atlantic, pushing the remnants of a modified old frontal
boundary near the region. Moisture content increases between late
Monday night and Tuesday, making it more likely to observe a showery
weather pattern.

&&

.LONG TERM. Wednesday through Sunday...

Persistent mid-level ridging across the eastern Caribbean will
keep conditions mainly stable throughout the long term period,
with some disruptions of an increase of passing showers due to an
increases of moisture at times. Remnants of an old frontal
boundary will move across the local area through Wednesday as a
surface high northeast of the region maintains a southeasterly
lower-level wind flow. This should bring some quick showers to
eastern PR and some light convection during the afternoon hours
across the interior to NW sections.

The arrival of dry air on Thursday morning is likely to
significantly decrease the potential for rainfall through Friday.
During this time, the building of a surface high in the western
Atlantic will cause lower-level winds to back, becoming
northeasterly by Friday. By Saturday this surface high is shown to
have strengthened greatly meanwhile stretching across the whole
western Atlantic. As a result, windy conditions from the east with
an increase of passing showers due to the advection of a moist
airmass will bring wetter conditions for the weekend. However mid-
level ridging will persist therefore no significant rainfall is
expected.

&&

.AVIATION...
(06Z TAFS)

Similar to yesterday, VFR conditions will persist through the
forecast periods. Occasional fragments of clouds will sometimes
arrive across the islands and may be accompanied by -SHRA/SHRA
affecting JSJ/IST/ISX/JBQ. Winds will persist mainly from the ENE-E
at 5-10 kt through 11/13z, increasing at around 15 kt with higher
gusts up to 25 kt and sea breeze variations.

&&

.MARINE...

A broad surface high pressure over the western Atlantic will move
east into the central Atlantic through Thursday at about 25 north
latitude. A strong low pressure in the north central Atlantic
will move northeast and into the northeast central Atlantic by
Tuesday. The low pressure system will send multiple similar pulses
of northeasterly swell into the local area, creating hazardous
marine and coastal conditions through at least Tuesday. As the
high pressure migrates east to the north of our area, northeast
winds will remain moderate to fresh and then turn easterly through
the rest of the period. Small Craft Advisories are in effect for the
Atlantic waters and local passages through at least Tuesday
afternoon. Please refer to the latest Marine Weather Message
(MWWSJU) for additional details.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Mon Feb 12 2024

.SYNOPSIS...
Issued at 459 AM AST Mon Feb 12 2024

A northeasterly swell will promote hazardous coastal conditions
due to life-threatening breaking waves and rip currents along the
north and east-facing beaches of Puerto Rico and the US Virgin
Islands. The high pressure north of the islands will promote
easterly winds that will push fragments of clouds and showers
across the islands each day, and the windward sections may observe
occasional periods of showery weather. Expect the typical
tropical winter temperatures. A mid to upper-level high pressure
will maintain a stable weather pattern across the Northeast
Caribbean.

&&

.SHORT TERM...Today through Wednesday...

Light showers associated with moisture from an airmass moving
westward across the eastern Caribbean were seen across eastern
Puerto Rico this early morning. Winds generally prevailed from the
east with speeds between 5 and 10 mph, with higher speeds across
coastal regions. The low temperatures were seen in the mid 70s along
the coastlines and in the low 60s across the mountains and valleys.

Today light showers may pass eastern Puerto Rico and the USVI
throughout the day, however due to mid to upper-level ridging across
the western Caribbean basin, generally stable conditions are to be
expected. Stratiform cloud coverage will move across the island,
causing cloudy skies throughout the day. No impressive amounts of
rainfall are to be expected today. Temperatures will be slightly
warmer today as a more easterly flow brings slightly warmer air
compared to the drier airmass to the northeast.

Through Wednesday, a surface high that is currently north of the
region will continue moving eastward further away from the islands.
Due to this, lower-level winds will begin to veer and remain with a
southeasterly direction by Tuesday. This will bring moisture into
the region, increasing the rate of passing showers through Tuesday
afternoon and through the night into Wednesday. Persistent showers
may bring some damp conditions across effected areas yet this
activity should be light and refreshing. The southeasterly direction
in the local lower-level flow will also bring warmer temperatures
especially for the northern sections of Puerto Rico.

.LONG TERM...Thursday through Monday...

Still, the mid to upper-level ridge will limit the upper-level
dynamic for organized flooding rains or thunderstorm development
during the long-term period. At the surface, a surface high
pressure extending from the Central to Eastern Atlantic will
promote the arrival of moisture across the islands, especially on
Thursday, when Precipitable Water (PW) may rise above 1.50 inches
of water. Then, a frontal boundary will approach the islands,
pooling additional moisture over the Northeast Caribbean Friday
into the weekend. This weather pattern may result in showery
conditions, especially across the windward sections during the
evening and early morning hours. Still, the subsidence above,
induced by the high pressure at mid-levels, will trap all the
moisture at low levels, limiting the vertical development of these
showers and the rainfall accumulations they may produce.

&&

.AVIATION...
(06Z TAFS)
Issued at 459 AM AST Mon Feb 12 2024

VFR conditions will persist. Occasional fragments of clouds will
sometimes arrive and may be accompanied by -SHRA/SHRA affecting
JSJ/IST/ISX/JBQ. Winds will persist mainly from the E-NE at 5-13
kt through 11/14z, increasing at around 15 kt with higher gusts up
to 25 kt and sea breeze variations during the afternoon.

&&

.MARINE...
Issued at 459 AM AST Mon Feb 12 2024

A subtropical high north of the islands will maintain a moderate
to locally fresh easterlies through Tuesday. Tuesday onward expect
winds to become moderate out from the east to east-southeast as
the surface high moves eastward into the Central Atlantic. Pulses
of northeasterly swell will promote hazardous marine conditions
for small crafts through at least Tuesday afternoon.

&&

.BEACH FORECAST...

A long period northeasterly swell continues deteriorating the
surf zone conditions, generating large breaking waves of 10 to 13
feet or higher across the Atlantic coastline from Rincon to
Fajardo, Culebra, and the U.S. Virgin Islands. This is creating
dangerous to life-threatening coastal conditions. Therefore, a
High Surf Advisory and a High Rip Current Risk Statement remains
in effect for these areas through at least Tuesday. A High Rip
Current Risk is also in effect for Vieques through at least
Tuesday.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
434 AM AST Tue Feb 13 2024

.SYNOPSIS...
Issued at 433 AM AST Tue Feb 13 2024

A subsiding long-period northeasterly swell continues promoting
hazardous coastal conditions due to life-threatening breaking
waves and rip currents along the north and east-facing beaches of
Puerto Rico and the US Virgin Islands.

A surface high pressure migrating into the Central Atlantic will
induce an east-southeast wind flow across the islands through
Thursday, and above-normal maximum temperatures will remain
possible during the afternoon. A frontal boundary will approach
the islands from the west, lingering north of the Northeast
Caribbean Friday through Saturday. The mid to upper-level trough
will hold throughout the forecast period.

&&

.SHORT TERM...Today through Thursday...

Mostly fair weather conditions prevailed overnight as drier air
prevailed across the region. There were some light passing showers
across eastern Puerto Rico, yet with barely any rain. Winds
generally prevailed from the east with speeds between 5 and 10 mph,
with higher speeds across coastal regions. The low temperatures were
seen in the mid 70s along the coastlines and in the low 60s across
the mountains and valleys.

A surface high pressure system northeast of the islands will
continue to move eastward into the central Atlantic, meanwhile
causing the local lower level wind flow to veer. Surface winds are
forecast to be southeasterly through Thursday and due to this,
warmer temperatures are expected and air with better moisture is
forecast to arrive Wednesday onward. For today, mainly fair weather
conditions will continue during the morning hours and an increase of
passing showers is likely due to a slight increase in moisture by
the evening. Eastern Puerto Rico will see the greater of this
activity as arrival moisture is very shallow as mid to upper-level
ridging continues to prevail across the eastern Caribbean.

Models were hinting at the arrival of a moist airmass on Wednesday
before the latest 13/00z run, however now it appears that is not
happening, instead a consistent influx of a slightly wetter air
continuing through Thursday. This will somewhat increase the
probability of showers through Thursday by raising precipitable
water values to more favorable levels compared to previous days.
It's possible that a perturbation in the trades at the surface
level will help increase convection throughout Wednesday night
through Thursday. For these days, we can expected an increase of
passing showers across southeastern Puerto Rico and the USVI,
followed by afternoon showers with a focus on northwestern PR. A
prevailing southeast flow around 10 knots with higher values
during the afternoon due to seabreeze acceleration should keep
most of the showers quick moving, without causing much of a
problem. However, urban areas with frequent showers may experience
some light ponding of water.

.LONG TERM...Friday through Tuesday...

A high-pressure ridge anchored at mid to upper levels over the
Northeast Caribbean is expected to remain in place through Monday,
weakening on Tuesday. This will limit upper-level dynamics, allow
dry air to be set up aloft, and trap the available moisture at
low levels. Meanwhile, the interaction between a surface high
pressure across the Central Atlantic and a cold front moving
eastward and positioning itself north of the region will pool
enough low-level moisture over PR and the USVI on Friday and
Saturday. Under this weather pattern, we may see occasional
showery weather on both days, and the rainy pattern will be tight
to the final position of the frontal boundary.

The surface high pressure will build from the Central to Eastern
Atlantic Saturday through next week, tightening the local pressure
gradient and promoting the east-southeast winds to increase on
Sunday, more easterly on Monday, and more east- northeast by
Tuesday. This weather pattern will leave the islands at the mercy
of the fragments of moisture that the winds may bring. Therefore,
the areas with more likeliness to observe occasional rains will be
the windward sections. Additionally, temperatures will range in
the typical values for this time of the year, with maximum values
in the mid and low 80s along the coasts and the mid and upper 70s
in the mountains. The low temperatures will drop in the low 70s or
upper 60s along the urban and coastal locations and from the low
60s to mid-50s in mountain areas and valleys.

&&

.AVIATION...
(06Z TAFS)
Issued at 433 AM AST Tue Feb 13 2024

VFR conditions will prevail through today and tonight. A slight
increase of moisture during the afternoon may bring an increase of
VCSH and cloud coverage across TJSJ/TIST/TISX/TJPS, yet nothing
impressive is expected. Afternoon convection may promote VCSH/SHRA
at TJBQ after 13/17z. ESE will prevail around 7-12 kts with higher
gusts and sea breeze variations after 13/13z.

&&

.MARINE...
Issued at 433 AM AST Tue Feb 13 2024

A surface high pressure drifting into the Central Atlantic will
maintain light to moderate east to southeast winds across the islands
through Thursday. A cold front will approach the islands from the
northwest, positioning north of the Northeast Caribbean from Thursday
onward. A fading long period northeasterly swell continues to create
hazardous marine and coastal conditions through at least this
afternoon.

Two pulses of long-period northerly swell are expected, with the
first arriving on Thursday, followed by a bigger one on Friday and
the weekend.

&&

.BEACH FORECAST...

Hazardous surf conditions due to a fading long period
northeasterly swell continue today. Therefore, expect breaking
waves up to 10 or 11 feet until this evening and a high risk of
rip currents throughout the day along the Atlantic Coastline from
Rincon to Fajardo, Culebra, and the U.S. Virgin Islands. Along the
Caribbean coastline of Puerto Rico from Yauco to Yabucoa, the risk
of rip currents is low.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
452 AM AST Wed Feb 14 2024

.SYNOPSIS...
Issued at 322 AM AST Wed Feb 14 2024

The surface high pressure extending from the Central to Eastern
Atlantic will promote a southeasterly wind flow, maintaining
above-normal temperatures for February across Puerto Rico and the
U.S. Virgin Islands through at least Thursday. A frontal boundary
will linger north of the islands on Thursday and Friday,
increasing low-level moisture across the region. Winds will
increase during the upcoming weekend. An increase in the available
moisture and enhanced showers may affect us on Tuesday and
Wednesday next week.

&&

.SHORT TERM...Today through Friday...

Fair weather prevailed overnight across the islands. Winds blew from
the southeast at around 5 to 10 mph, however over mainland Puerto
Rico light land breezes dominated. The low temperatures were seen in
the mid 70s along the coastlines and in the low 60s across the
mountains and valleys.

A calm, clear to partly cloudy sky will prevail through the morning
hours before afternoon convection due to diurnal heating and
seabreeze convergence allows showers to form across the interior to
western sections of Puerto Rico. A surface high pressure migrating
across the central Atlantic will maintain southeasterly winds
through at least tomorrow which will continue this trend of clear,
calm mornings followed by an increase of rainfall during the
afternoon. Moisture begins to increase on Thursday, therefore
expected more showers than previous days.

Winds begin to back on Friday as a high pressure system at the
surface forms across the western Atlantic. Winds speeds are forecast
to increase to around 10 to 15 knots and prevail from the east at
the surface, causing a better potential for passing showers for the
USVI and eastern PR and afternoon convection across western Puerto
Rico. Overnight on Friday a moist airmass may lift from the south
and move into the islands. However, we remain skeptical over the
reality of this happening since this is the same solution that was
showing to arrive on Tuesday, yet keeps getting pushed one day
later. Therefore, expect a seasonal pattern of passing showers and
afternoon convection to prevail.

&&

.LONG TERM...Saturday through Wednesday...

The mid to upper-level high-pressure ridge lingering aloft the
Northeast Caribbean will promote a stable atmosphere, with dry air
intrusion at mid and upper levels and a strong trade wind cap
trapping all the moisture at low levels. Meanwhile, the surface
high pressure migrating from the Central to Eastern Atlantic will
promote the advection of fragments of moisture that, in some
instances, will result in rainy conditions during the weekend.
However, we expect a mixture of sunshine/mostly clear skies and
clouds. The surface high-pressure building across the Atlantic
will induce breezy east-southeasterly winds on Saturday and
Sunday.

An induced perturbation embedded in the trades with a mixture of
tropical and residual moisture associated with the frontal
boundary forecast to linger north of the islands this week
(Thursday and Friday) may be advected toward PR/USVI, arriving
Monday through Wednesday of next week, increasing the potential
for pesky showers across the region. As this occurs in the low-
levels, an approaching polar trough will weaken the ridge of high
pressure at upper levels, which may enhance the intensity of
showers, especially on Tuesday and Wednesday. &&

&&

.AVIATION...
(06Z TAFS)
Issued at 322 AM AST Wed Feb 14 2024

VFR conds through prd. Isolated SHRA in and around the islands and
over the regional waters btw PR and the USVI terminals. VCSH psbl
at TJSJ/TJPS/TJBQ but no sig wx impacts anticipated. Aftn SHRA psbl
at TJBQ 14/19-23Z. ESE will prevail around 7-12 kts with higher
gusts and sea breeze variations, bcmg lgt/vrb aft 14/23z.

&&

.MARINE...
Issued at 322 AM AST Wed Feb 14 2024

The surface high pressure extending from the Central to Eastern
Atlantic will maintain light to moderate east to southeast winds
until early Friday morning. The approaching cold front will linger
north of the Northeast Caribbean from Thursday through late Friday
night while another subtropical high drifts eastward across the
Western Atlantic. During this time, pulses of long period northerly
swells will spread across the region. The first pulse will occur on
Thursday, followed by a larger one on Friday.

&&

.BEACH FORECAST...

The rip current risk will drop to moderate due to a small, long
period, northeasterly swells moving across the Atlantic Waters.
The CariCOOS buoy network (when writing the discussion) measured a
dominant period of 13-14 seconds, a wave height of around 3 feet,
and a wave direction from the northeast. Therefore, the risk is
moderate for the beaches from Rincon to Ceiba, northern Culebra,
St Thomas, and St John, as well as the eastern half of St Croix.
The Caribbean Coastline has a low risk of rip currents.

The risk of rip currents will increase once again along the
Atlantic coastline on Friday with the arrival of a pulse of
another long period northerly swell.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
420 AM AST Thu Feb 15 2024


.SYNOPSIS...
Issued at 414 AM AST Thu Feb 15 2024

The proximity of a pre-frontal trough will cause light steering
winds and moisture convergence, promoting an increase in shower
activity across central Puerto Rico today. More stable weather
conditions are expected to return tomorrow through the weekend.
Hazardous marine and coastal conditions will also return by Friday
and persist through the weekend.

&&

.SHORT-TERM...Today through Saturday...

An overnight radar and satellite imagery analysis indicated all land
areas remained cloud- and rain-free. Overnight temperatures from
official reporting sites ranged from around 60 degrees in higher
elevations to about 75 degrees across the San Juan metropolitan
areas. Winds were generally light and variable.

For today, the proximity of a pre-frontal trough will cause lighter
winds, at or below ten mph, with a slight east-to-east-northeast
component. At mid-to-upper levels, a subtropical jet along the
southern periphery of a solid polar trough will sink south enough to
displace a persistent mid-level ridge southeastward and away from
the northeastern Caribbean. Despite the expected erosion of the
trade wind cap with this displacement, allowing moisture to lift
higher into the 750-700 mbar layers, precipitable water should
remain within the lower end of typical seasonal thresholds of around
1.2 inches. Meanwhile, warmer-than-normal temperatures at the 925
and 500 mbar layers will persist, with surface daytime high
temperatures peaking into the mid 80s to about 90 degrees. Since the
environment will likely become favorable for deep convective
development, the appropriate combination of diurnal heating, local
effects, and a weak steering flow may induce afternoon slow-moving
showers that could produce localized rainfall totals of around an
inch, possibly causing flooding impacts, especially along the
interior to western interior sections of Puerto Rico. The U.S.
Virgin Islands should remain rain-free under mostly sunny skies.

By Friday and Saturday, another mid-level ridge will move into the
northeastern Caribbean from the west, re-establishing the trade wind
cap inversion and hostile conditions for deep convective development
while maintaining the bulk of the available moisture capped below
the 850 mbar layer. The occasional patch of moisture may bring light
passing showers, but overall, expect fair weather conditions with
mostly clear skies across the region. Winds will gradually veer from
the east on Friday and southeast on Saturday, with wind speeds of 10-
15 mph from Friday night onwards, attributed to a surface high
pressure spreading across the North Atlantic. The general forecast
features seasonal overnight low temperatures into the mid 60s across
higher elevations and above-seasonal daytime high temperatures into
the upper 80s across lower elevations.

&&

.LONG TERM...Sunday through Thursday...

A strong mid- to upper-level ridge will dominate the northeastern
Caribbean, promoting an inversion cap and stable weather conditions
by the end of the weekend into early next week. This weather setup
will lead to subsidence aloft, maintaining warm 500 mb temperatures
and hindering any deep convective activity across the area. At low
levels, the long-term forecast starts with well below normal
moisture content, with precipitable water values dropping below 1.0
inches on Sunday. In the following few days, some patches of
moisture embedded in the trades will bring occasional light showers
across windward coastal areas at times, particularly during night
and morning hours.


By Wednesday through Thursday, a polar trough will exit the Eastern
Seaboard and erode the mid-level ridge. As the polar trough moves
over the forecast area, cold air advection will cause 500 mb
temperatures to plummet to -8 degrees Celsius, resulting in
increased vertical mixing and unstable weather conditions aloft.
At low levels, the associated frontal boundary will approach from
the northwest, promoting moisture convergence over the local
islands. Precipitable water values will increase above 2.0 inches
by Thursday. Consequently, the end of the long-term forecast will
transition to a wet weather pattern, with scattered to numerous
showers likely over the local area. Thunderstorm activity can also
be anticipated due to the presence of unstable weather conditions
and increased moisture convergence, which could lead to limited
and elevated flooding threats across the islands. However, since
this forecast period is still distant, uncertainty is high for
this weather setup. We will continue to monitor forecast trends
and provide updates as needed.

&&

.AVIATION...
(06Z TAFS)
Issued at 414 AM AST Thu Feb 15 2024

VFR conditions will prevail at all terminals, with an increased
chance of SCT-BKN between FL020-040 and SHRA across PR terminals
between 15/16-23Z, possibly leading to brief MVFR conditions. Light
and variable winds, increasing to 8-12 knots with sea breeze
variations between 15/14-23Z. Wind speeds will become light and
variable again after 15/23Z.

&&

.MARINE...
Issued at 414 AM AST Thu Feb 15 2024

A surface high-pressure system migrating from the central to eastern
Atlantic will maintain light to moderate east to southeast winds
until early Friday morning. Meanwhile, a stationary front will
linger north of the northeastern Caribbean through late Friday night
as another surface high-pressure system moves eastward across the
Western Atlantic. Consequently, pulses of long-period dominant
northerly swells will spread across the region. The first pulse is
expected to arrive by late tonight, followed by a larger pulse on
Friday.

&&

.BEACH FORECAST...
Issued at 414 AM AST Thu Feb 15 2024

A moderate risk of rip currents is expected across the coastal areas
of Puerto Rico from Aguadilla to Humacao, including Culebra and St.
Croix. By Friday night through the weekend, pulses of long-period
northerly swells will elevate breaking waves across the northern
areas of Puerto Rico, leading to hazardous beach conditions across
the islands.

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
442 AM AST Fri Feb 16 2024


.SYNOPSIS...
Issued at 429 AM AST Fri Feb 16 2024

Some shower activity across northwestern portions of Puerto Rico
are possible this afternoon. Mostly stable weather conditions with
limited showers at times expected through early next week before
another polar trough and frontal boundary approaches the area by
late next week. Hazardous marine and coastal conditions will
return today and persist through at least Saturday.

&&

.SHORT-TERM...Today through Sunday...

An overnight radar and satellite imagery analysis indicated a
persistent line of showers developed across northern Puerto Rico,
lasting from around 8 PM AST through 3 AM AST, producing isolated
radar-estimated rainfall totals of around 1-2 inches across
municipalities of the north-central to northwestern Puerto Rico.
Elsewhere, including the US Virgin Islands, mainly clear to partly
cloudy skies prevailed. So far, overnight temperatures from official
reporting sites have ranged from 62 degrees in higher elevations to
75 degrees across lower elevations. Winds were generally light to
calm and variable.

For today, the proximity of a pre-frontal trough to the north will
maintain lighter winds, remaining at or below ten mph during the
morning hours. As the day advances, winds will gradually shift from
the east to the east-southeast and increase to 10-15 mph, influenced
by a distant surface high surface pressure over the north-eastern
Atlantic. Simultaneously, a mid-level high-pressure system to the
west will extend into the northeastern Caribbean, gradually
reinstating a trade wind cap inversion. Although capped below the
850 bar layers, the region will remain under an airmass with normal
to slightly above-normal available moisture, increasing from 1.2
inches in the morning to 1.5 inches during peak diurnal heating in
the afternoon. This transition may induce shallow afternoon
convective development, particularly along the interior into
northern sections of Puerto Rico. While significant rainfall
accumulations are not likely, isolated totals of half to three-
quarters of an inch are possible, with the heaviest rains over the
northwestern quadrant of Puerto Rico leading to minor flooding
impacts, such as water ponding on roadways and poorly drained areas.
Conversely, the U.S. Virgin Islands and the local islands should
remain rain-free under mostly sunny skies. With southeasterly winds
and warmer-than-normal temperatures at the 925 mbar layers, daytime
high temperatures across lower elevations and urban areas are
forecast to peak into the mid-80s to around 90 degrees.

Following the most recent model guidance, the mid-level high
pressure will meander over the forecast area on Saturday before
slowly lifting northeastward on Sunday. This feature will maintain a
strong trade wind cap inversion and influx of drier air above the
850 mbar layers, creating unfavorable conditions for deep convective
development. On Saturday, a patch of shallow moisture will cause
increased moisture levels, potentially causing brief showery
conditions. However, Sunday will likely experience much drier
weather conditions, with precipitable water values dropping
significantly below normal levels, supporting the lowest daily
chance of rain (20-30%) within the short-term period. Throughout the
weekend, winds will persist from the east to east-southeast, with a
notable increase in speeds up to 15-20 mph or breezy conditions on
Sunday, attributed to the tightening of the local pressure gradient.
The overall forecast indicates warmer-than-normal daytime high
temperatures reaching into the upper 80s over the weekend,
accompanied by a trend of warmer overnight lows. Under these
conditions, an elevated fire danger risk is possible on Sunday.

&&

.LONG TERM...Monday through Friday...

Models are fairly consistent with the start of the long-term
forecast. A robust mid-level ridge will dominate the northeastern
Caribbean by early next week. This will promote an inversion cap
between 850-700 mb, trapping moisture below this layer. Near-normal
to slightly above-normal low-level moisture content will prevail
across the islands due to the passage of patches of moisture
through the CWA. Consequently, periods of clear to variably cloudy
skies and limited showers are expected, with showers occurring
mostly over windward coastal areas at times. However, rainfall
accumulations are not expected to be significant during this early
part of the forecast. East-southeast winds are expected to
prevail through mid-week next week, promoting warmer temperatures
across the islands.

As the week progresses, the mid-level ridge will erode as a polar
trough and associated frontal boundary approach from the northwest.
Uncertainty exists regarding the amount of convective and shower
activity that will result from this weather setup across the
islands, as models now project it farther north than in previous
cycles. The NBM indicates a less than 20% probability of observing
thunderstorms, mostly over the Atlantic waters and brushing the
northern coastal areas of Puerto Rico. Despite discrepancies in the
positioning of the polar trough, precipitable water content is
expected to increase close to 2.0 inches over land areas, with 500
mb temperatures dropping close to -10 degrees Celsius. Therefore,
unsettled weather conditions are anticipated to be present,
gradually transitioning on Wednesday and lingering through early
Friday.

Wednesday could see afternoon convection as the pre-frontal trough,
surface heating, and local effects combine to produce convective
activity across interior/northwestern Puerto Rico. Shower and
convective activity from late Wednesday through Thursday will depend
on the behavior of the polar trough and frontal boundary. The
highest amounts might be observed during the peak hours of Thursday,
affecting mostly the northern coastal areas of Puerto Rico, Culebra,
and the northern USVI. The greatest flooding threat is anticipated
on Thursday, with a limited to localized elevated flooding threat
primarily affecting the northern half of the CWA. Additionally, wind
speeds are expected to drop as the frontal boundary approaches the
area. This could enhance the residence time of storms, increasing
rainfall accumulations in some areas. Stay tuned for further updates
as we continue to monitor forecast trends for next week's event.

&&

.AVIATION...
(06Z TAFS)
Issued at 429 AM AST Fri Feb 16 2024

VFR conditions will prevail at all terminals, with a chance of
SCT-BKN between FL020-040 and VCSH between 16/14-23Z for TJSJ,
16/17-23Z for TJBQ, and after 16/23Z for TJPS, possibly leading to
brief MVFR conditions. Light and variable winds, increasing to
10-14 knots with sea breeze variations between 16/14- 23Z. Wind
speeds will become light and variable again after 16/23Z.

&&

.MARINE...
Issued at 429 AM AST Fri Feb 16 2024

A surface high-pressure migrating from the central to eastern Atlantic
will maintain light to moderate east to southeast winds until early
morning today. A stationary front will linger north of the northeastern
Caribbean through late tonight as another surface high pressure
moves eastward across the Western Atlantic. Pulses of long-dominant
period northerly swells will spread across the Atlantic waters and
passages through the weekend. Therefore, Small Craft Advisories are
in effect. Please refer to the latest Marine Weather Message (MWWSJU)
for more information.

&&

.BEACH FORECAST...
Issued at 429 AM AST Fri Feb 16 2024

Offshore buoy 41043 is already indicating the presence of pulses of
northerly swell on the way to the northern shores. With these
observations, estimated breaking waves will range between 6 to 9
feet throughout the day, occasionally reaching 10 feet on beaches
with steep underwater slopes. Additionally, pulses of northerly
swells will continue to invade the northern regional waters
through at least Saturday. Therefore, High Risk of Rip Current
Statements are in effect for the northern exposed beaches of
Puerto Rico, Culebra, and the northern USVI. A High Surf Advisory
cannot be ruled out, particularly for late tonight and tomorrow.
We will continue to monitor observations and issue the advisory if
necessary. For more information and details, please refer to the
latest Surf Zone Forecast (SRFSJU) and the Coastal Hazard Message
product (CFWSJU).

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
407 AM AST Sat Feb 17 2024

.SYNOPSIS...The weather pattern should remain relatively dry and
stable despite a patchy weather scenario prevailing into early
next week. An old frontal boundary and associated pre-frontal
trough and moisture field aligned with a polar trough could
promote increased shower activity by midweek next week. Hazardous
marine and coastal conditions will continue through the weekend.


&&

.SHORT TERM...Today through Monday...

Both satellite-derived precipitable water (PWAT) and Doppler radar
indicate below- to near-normal moisture content over the region,
with only a few very isolated showers observed over the local waters
during the night hours. This trend is expected to persist during the
morning hours. Minimum temperatures were in the mid- to upper-70s
along the coastal areas, and around the low 60s in higher elevations
and valleys.

At the surface level, a high-pressure system over the central
Atlantic will continue moving eastward, followed by a frontal low
exiting the Florida Peninsula into the western Atlantic. This
synoptic weather setup will influence the region by promoting east-
southeast winds today and persisting through early next week across
the local islands, with wind speeds gradually increasing as the
pressure gradient tightens over the northeastern Caribbean. This
will result in breezy wind conditions throughout the weekend along
coastal and some localized mountainous areas. Southeast winds will
contribute to higher temperatures across the islands, particularly
on Monday.

The building of the mid-level ridge will also impact the region by
promoting a strong trade wind cap, limiting deep convective
development. Any moisture reaching the area will likely be confined
below approximately 800 mb, as dry air persists in the mid to upper
levels. Intervals of humid and drier air masses will move toward the
islands through the short-term forecast, with Sunday afternoon
through Monday morning expected to be the driest period.

Therefore, the weekend through Monday will be characterized by very
isolated passing shower activity being advected towards windward
sections at times, while also crossing the local waters. Stronger
showers are more likely to occur when patches of more moist air are
crossing the region, but overall, very minimal rainfall
accumulations are expected. Afternoon convection could also develop
due to diurnal and local effects, but should be short-lived,
promoting ponding of water in roadways and poorly drained areas in
very localized spots.

.LONG TERM...Tuesday through Saturday...

Although the long-term forecast period features a general wet
trend, brief intervals where moisture levels may dip to normal or
below-normal levels are still likely, measuring below 1.2 inches.
A substantial decrease in available moisture is anticipated from
Tuesday morning to Wednesday morning. This dry period will be
followed by a quick increase in moisture, surpassing normal
thresholds on Thursday, as an old frontal boundary and its
associated moisture field cross the islands from the north.
Moisture levels are expected to revert to typical thresholds on
Friday as drier air moves in the wake of the frontal boundary and
the remnants remain south of the forecast area across the
Caribbean waters. However, over the weekend, moisture levels are
projected to surge again to above-normal seasonal levels as the
remnants are pushed back over the local islands.

A transition of synoptic features is also expected. At mid-to-
upper-levels, a high pressure, maintaining a strong inversion and
dry air above the 850 mbar layers, is forecasted to shift
northeastward and away from the area due to the influence of a
polar trough on Tuesday. This trough will cross the local islands
on Wednesday and Thursday before lifting northeastward into the
North Central Atlantic by Friday. Subsequently, a gradual re-
establishment of a ridge is anticipated over the weekend.
Simultaneously, at the surface, east to east-southeast winds,
generated by a distant surface high pressure in the North
Atlantic, are forecast to gradually weaken and become variable on
Wednesday as a response to the passage of the pre-frontal trough.
After this, winds are projected to intensify and shift from the
north on Thursday and Friday in response to the flow following the
frontal boundary. The weekend is expected to see the return of
easterly winds.

Overall, expect an increase in shower activity between Wednesday
and Thursday and again during the weekend. The highest impact,
however, is expected by midweek, with the alignment of the pre-
frontal trough at the surface, polar trough aloft, and increased
moisture levels likely generating flooding impacts across the
local islands. Warmer-than-normal temperatures will persist until
winds turn from the north and shower activity increases by the
second half of the workweek.


&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions are expected across all terminals. Very isold
SHRA moving across TJBQ after 17/18z could promote briefly MVFR
conditions. Wind flow generally from the ESE at up to 10-15 kts with
higher gusts and sea breeze variations.


&&

.MARINE...

A surface high pressure migrating from the central to eastern
Atlantic will maintain gentle to moderate east to southeast winds
through early next week. Pulses of long dominant period northerly
swells generated from a distant low pressure system across the
Atlantic will spread across the local Atlantic waters and passages,
maintaining hazardous marine conditions for small craft through this
evening.


&&

.BEACH FORECAST...

Life-threatening rip current conditions will continue for most
north-facing beaches of Puerto Rico, Culebra, and the northern
U.S. Virgin Islands through Sunday afternoon. High Surf conditions
will likely continue across these areas, and a High Surf Advisory
remains in effect through this evening. For more information,
please refer to the latest Coastal Hazard Message (CFWSJU) and
Surf Zone Forecast (SRFSJU).

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
408 AM AST Sun Feb 18 2024

.SYNOPSIS...During the next 5-7 days, primary hazard risks focus
on marine and rip currents through late tonight, driven by pulses
of a northerly swell, and non-thunderstorm winds attributed to the
tightening of the local pressure gradient through Monday. Small
Craft Advisories remain in effect for the Mona Passage through
late tonight, but small craft should exercise caution elsewhere.
Surf heights will likely peak around 6-8 feet across northern
exposed Atlantic coastlines, supporting the ongoing life-
threatening rip current conditions through late tonight.
Additionally, excessive rainfall hazard risks are likely as an old
frontal boundary crosses the local islands by Wednesday into
Thursday. The prevailing southeasterly flow will persist,
supporting warmer-than-normal temperatures through midweek.


&&

.SHORT TERM...Today through Tuesday...

During the night hours, no rain and very few clouds were detected by
infrared satellite and Doppler radar, and this trend is expected to
persist for the rest of the morning hours. Minimum temperatures were
in the low to mid-70s along the coastal areas and around the low 60s
in higher elevations and valleys.

The synoptic pattern across Puerto Rico and the U.S. Virgin Islands
will continue to maintain stable weather conditions throughout the
short-term forecast. Winds will remain east-southeast and breezy,
bringing warmer-than-normal temperatures over the forecast area.
Strong ridging aloft will persist, maintaining a notable inversion
cap between 900-850 mb, particularly today and Monday. This
inversion will effectively suppress vertical mixing and limit
convective development. Low-level moisture is expected to be
confined below the inversion layer and remain mostly below the 25th
percentile of climatological levels, which is below normal for this
time of year. Therefore, mostly sunny to partially cloudy skies are
expected, with very isolated showers, if any, affecting southeastern
sections of the islands during late night to early morning hours.

By late Monday through early Tuesday, a subtle change in weather
conditions is anticipated as a patch of low-level moisture moves
over the local islands. Moisture content is expected to increase to
near-normal levels, potentially debilitating and raising the
inversion layer. While this increase in moisture content may lead to
some cloud coverage and shower activity, particularly along windward
coastal areas, significant rainfall amounts are not expected. The
overall precipitation outlook remains modest, with only scattered
to, at times, numerous showers anticipated over southeastern
portions of the islands during the morning hours. This may cause
slippery roads and some ponding of water in roadways in localized
regions. Additionally, afternoon showers over northwestern Puerto
Rico are also possible.

.LONG TERM...Wednesday through Sunday...

The long-term forecast period continues to feature comparable
periods of well-above and well-below seasonal moisture, but model
guidance now suggests these transitions earlier than previously
suggested. A rapid increase in precipitable water, from below-
normal levels of around 1.1 inches on Wednesday morning to two
standard deviation above-normal levels of about 1.8 inches on
Wednesday night, is likely, followed by a comparable drop into
well-below-normal levels of approximately 0.8 inches by Thursday
evening, responding to a quick passage of an old frontal boundary
and associated moisture field across the islands from the north.
Drier-than-normal conditions will persist on Friday and early
Saturday, followed by a smoother increase in precipitable water to
nearly well-above-normal moisture levels from Saturday evening
into Sunday as the remnants are steered back over the local
islands from the southeast.

At mid-to-upper levels, an eastward-moving polar trough will cross
the northeastern Caribbean on Wednesday and Thursday before
lifting northeastward into the North Central Atlantic by Friday.
Subsequently, a gradual re-establishment of a ridge is anticipated
over the weekend. Simultaneously, at the surface, winds will
gradually weaken and become variable on Wednesday as a response to
the passage of the pre-frontal trough. After this, winds are
projected to intensify and shift from the north on Thursday and
Friday in response to the flow following the frontal boundary. The
weekend is expected to see the return of easterly winds at
lighter wind speeds.

Overall, expect an increase in shower activity between Wednesday
and Thursday, with a recurrence over the weekend. The highest
impact, however, is expected by midweek, with the alignment of the
pre-frontal trough at the surface, polar trough aloft, and
increased moisture levels likely generating flooding impacts
across portions of the local islands. Except for Thursday and
Friday, when cooler-than-normal temperatures are likely, seasonal
temperatures will return to the region. This cooling effect can
be attributed to prevailing northerly winds steering a cooler and
drier air mass following the passage of the frontal boundary.


&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions are expected across all terminals, with sfc
wnds prevailing ESE reaching speeds of up to 10-15 knots,
accompanied by higher gusts and sea breeze variations aft 18/13z. No
sig wx impacts are anticipated durg prd.

&&

.MARINE...

A surface high pressure over the northeastern central Atlantic
will maintain gentle to moderate southeasterly winds through early
next week. Pulses of a long-period northerly swell, generated
from a distant low-pressure system across the Atlantic, will
continue spreading across the local waters and passages,
maintaining hazardous marine conditions for small craft,
particularly across the Mona Passage, until late tonight.
Elsewhere, small craft should continue to exercise caution.


&&

.BREACH FORECAST...

Life-threatening rip current conditions will continue for most
north-facing beaches of Puerto Rico, Culebra Vieques, and the
northern U.S. Virgin Islands today. As a result, a Rip current
Statement remains in effect through late tonight. For more
information, please refer to the latest Coastal Hazard Message
(CFWSJU) and Surf Zone Forecast (SRFSJU).


&&

.FIRE WEATHER...

Despite notable discrepancies in KBDI readings between Cabo Rojo
and Guanica in southwestern Puerto Rico, Guanica's KBDI readings
persist in indicating that the soil conditions in the area are
conducive to the spread of wildfires. Although data for Camp
Santiago is unavailable, conditions should be similar across the
southeastern coastal plains, where it has not rained in over ten
dayS. Today, winds will likely again exceed the fire danger
threshold of 15 mph. Notably, a drier-than-normal air mass will
invade the region today, causing lower humidity levels.

Consequently, there is an elevated risk of fire danger today,
requiring the issuance of a Fire Danger Statement (RFDSJU) for all
of Puerto Rico, considering the latest 7- to 14-day rainfall
deficits and persistent abnormally dry to moderate drought
conditions. Users are encouraged to stay vigilant and monitor
subsequent updates throughout the day for any potential changes.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Mon Feb 19 2024

.SYNOPSIS...

Drier and stable conditions will persist across the islands
today with limited precipitation. A frontal boundary is expected
to approach the local area by mid-week, increasing the potential
for wetting rains. Cooler-than-normal temperatures are anticipated
by the latter part of the week after the frontal passage. Marine
conditions will continue to improve with a fading northerly swell
departing the region.

&&

.SHORT TERM...Today through Wednesday...

Mostly clear skies prevailed across the region overnight with only a
few passing clouds and little or no precipitation noted crossing the
regional waters and local islands. The overnight low temperatures
were in the mid-upper 70s along the coastal areas, and near the mid
60s to low 70s over the mountainous areas and valleys. Winds
overnight became calm to light and variable.

A surface high pressure extending from the central and eastern
Atlantic will aid in promoting a southeasterly wind flow across the
region today, then becoming more easterly by Tuesday while gradually
diminishing and becoming light and variable on Wednesday. An overall
dry and stable airmass with mostly fair weather skies and limited
precipitation are forecast for today with above-normal high
temperatures expected particularly along the north coastal areas of
Puerto Rico and St Croix through Tuesday.

By late Tuesday through Wednesday and induced prefrontal trough, and
cold frontal boundary will approach and linger across the region
resulting an increase in pooling of moisture and convergence.
Consequently the potential for wetting rains is forecast is to
increase by late Tuesday and through Wednesday night, as a low
pressure system and associated cold front across the west and
central Atlantic is to lift the remnant frontal boundary moisture
across the region. In addition, the upper ridge presently in place
is to erode and give way to a polar trough which is forecast to
cross the region, resulting in unstable condtions aloft and an
erosion of the trade wind cap inversion. Periods of enhanced shower
activity will therefore be possible across the region beginning
Tuesday afternoon and continuing through Wednesday.

Recent model guidance also suggest a shift in the synoptic pattern
from stable weather conditions to a more unstable and moist
environment, with precipitable water increasing from an inch or less
today into Tuesday, to between 1.50 and 1.70 inches by late Tuesday
through Wednesday. This is all in response to the approaching polar
trough and cold front and associated moisture field. The greatest
impact for the period will be the increasing chance for wetting
rains. This may lead to ponding of water on roads and poor drainage
areas along with the possibly of minor urban flooding in isolated
areas across eastern and northern Puerto Rico late Tuesday and
Wednesday. There is a better chance for the USVI on Wednesday. There
is however a slight disagreement in the GFS and Euro models in the
timing of the rains accompanying these features but all point to a
wetter pattern by the middle of the week.

&&

.LONG TERM...Thursday through Monday...

After the passage of a frontal boundary and its associated moisture,
drier air will start to filter into the local area. A drop in
precipitable water content is expected on late Thursday, with values
between 0.90 to 1.00 inches. Drier conditions are forecast for
Friday into Saturday, with no significant precipitation over the
islands. However, by late Saturday an increase in moisture is
expected, as the remnants of the frontal boundary steers back from
the southeast. The wind flow is expected to shift from the north by
Thursday and Friday in response to the frontal boundary. Therefore,
cooler-than-normal temperatures are likely over the islands. By
Saturday onwards, winds will shift back from the east and returning
to seasonal temperatures. Drier air will inhibit shower formation
over the local islands for the beginning of the period. However,
passing showers cannot be ruled out, mainly across the windward
portions of the islands. By late Saturday, with the increase in
moisture, showers may develop across the Caribbean waters and moving
into portions of eastern Puerto Rico and the US Virgin Islands.
Unstable weather conditions are anticipated for Sunday and Monday,
that may result in isolated to scattered showers mainly across
central and western Puerto Rico during the afternoon hours. Daytime
temperatures will range from the mid to upper 80s across the coastal
and urban areas, and low to mid 80s in the higher elevations.

&&

.AVIATION...
(06Z TAFS)

VFR durg prd. FEW clds nr FL025...FL040. SKC abv. Isold -SHRA ovr
regional waters and en route btwn islands. Sfc wnds calm to lgt/vrb,
bcmg fm ESE 12-15kt with sea breeze variations aft 19/14Z. L/Lvl
wnds fm SE 15-20 kts BLO FL120. Few SHRA ovr ctrl and NW PR fm 19/18-
19/22Z. No sig operational wx impact durg prd.

&&

.MARINE...

A surface high pressure extending from the Eastern Atlantic into the
Northeast Caribbean will continue to promote moderate to fresh east
to southeast winds through late this evening. Seas will slowly
improve as the fading northerly swell leaves the local region.
A surface low pressure with its frontal boundary are moving eastward
across the Western Atlantic and will approach the local islands by
mid-week. This will promote gentle to moderate easterlies Tuesday,
becoming gentle and variable Wednesday and early Thursday. Winds will
become moderate to fresh out from the north Thursday into Friday.

&&

.BEACH FORECAST...

CariCOOS bouy network observations report seas between 2 to 4 feet
across the regional waters. At this moment there is a moderate
risk of life-threatening rip currents across all the islands of
Puerto Rico and the U.S. Virgin Islands. The risk will become low
later tonight for most of the beaches from Dorado to Aguadilla,
western and southern Puerto Rico, including Vieques, and Saint
Croix. The risk will be low on Tuesday and Wednesday for all the
islands.

&&

.FIRE WEATHER...

Dry and stable conditions are expected today with limited
precipitation across the region. Discrepancies in KBDI readings
continue with the Guanica and Cabo Rojo sites in Puerto Rico, with
Guanica reporting values within the fire danger criteria. Winds will
continue from the southeast at 10 to 15 mph. RH values may drop
to the low 50s, especially across the southern and southwestern
plains of Puerto Rico. Due to the current conditions, the fire
danger risk for today should remain limited. However, we will
continue to closely monitor throughout the day, and a Fire Danger
Statement (RFDSJU) will be issued if conditions warrant. Users
are advised to monitor further updates during the day for any
changes.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
416 AM AST Tue Feb 20 2024

.SYNOPSIS...

Relatively dry and stable conditions are expected to prevail
today across much of the region. Passing showers will affect the
local waters during the morning hours. However, limited
precipitation is forecast for most of the islands today. Above-normal
temperatures are expected once again, especially along the coastal
and urban areas of Puerto Rico and the U.S. Virgin Islands. A
surface low pressure and its frontal boundary will approach the
local area by Wednesday. Therefore, unstable weather conditions
are anticipated.

&&

.SHORT TERM...Today through Thursday...

Mostly clear to partly cloudy skies prevailed across the region
overnight with few passing showers noted mainly over the offshore
coastal waters and south and east coastal areas of the islands.
Rainfall accumulations were minimal and insignificant so far. The
overnight low temperatures were so far in the mid-upper 70s along
the coastal areas, and in the mid 60s to near 70 degrees in the
higher elevations and valleys. Winds were calm to light and variable.

A broad surface high pressure ridge continued to extend into the
northeastern Caribbean from the central and northeast Atlantic,
while a series of low pressure systems and associated cold front
continued to cross the west and southwest Atlantic. This will aid in
promoting a fairly light east to southeast low level wind flow today
while gradually diminishing and becoming light and variable by
Wednesday as a prefrontal trough and frontal boundary approaches the
region. A mid to upper level high pressure ridge will hold across
the region but is to gradually erode later today and through the
rest of the period with the approach of a polar trough. In the
meantime, an overall dry and stable airmass with mostly fair weather
skies and limited precipitation is forecast for most of the islands
today with again above-normal high temperatures expected especially
along the north coastal areas of Puerto Rico and St Croix in the
USVI. However with a slight increase in moisture later today, some
late afternoon and evening showers cannot be ruled out.

Later today and through Wednesday, an induced prefrontal trough, and
cold frontal boundary will approach and linger across the region
resulting an increase moisture pooling and good low level
convergence. In addition, the upper ridge will continue to erode as
a polar trough is forecast to deepen and cross the region through
early Thursday. The combination of the aforementioned features will
therefore create unstable conditions aloft and good moisture
convergence favoring good potential for wetting rains across
portions of the islands Wednesday through early Thursday, as the low
pressure system and associated cold front across the west and
central Atlantic lifts the remnant frontal moisture across the
region. Based on recent model guidance,the best chance for enhanced
shower activity across the region will be Wednesday through early
Thursday with rapid improvement by Thursday afternoon as a surface
high pressure ridge will build across the west Atlantic and winds
become more northerly, bringing in drier air and more stable
airmass.

That said and with model guidance now in better agreement, the
greatest impact for the period will be the increasing chance for
wetting rains Wednesday through early Thursday. However there will
still be a chance for afternoon showers across western Puerto Rico
by late afternoon and early evening today. The expected periods of
locally heavy rains may lead to ponding of water on roads and poor
drainage areas along with the possibly of minor urban flooding in
isolated areas especially across western and the northern half of
Puerto Rico, beginning late today and continue through Wednesday
with the potential for shower activity possibly lingering across
portions of eastern Puerto Rico and the USVI late Wednesday through
early Thursday.

&&

.LONG TERM...Friday through Tuesday...

A building surface high pressure moving from the western to central
Atlantic will dominate the local conditions for the first half of
the long-term period. Northerly winds in response to the high
pressure, will bring drier air and stable conditions across the
islands. The recent model guidance shows limited precipitation, with
Precipitable Water content values of 0.70 to 0.80 inches until
Sunday. As the surface high builds, winds will predominate from the
north until Saturday. Then, winds will shift back from the east to
southeast in response of the lifted remnants of the frontal boundary
from the southeast. Therefore, an increase in moisture is expected
throughout the region. This will enhance shower formation from
eastern Puerto Rico and the U.S. Virgin Islands during the
morning hours, through western Puerto Rico in the afternoon. By
late Sunday into Monday, conditions will turn into a wet pattern.
Another cold front that moved off the eastern coast of Continental
United States will approach the local area, promoting unstable
conditions through Tuesday. Cooler-than-normal temperatures are
expected from Thursday to Friday, with overnight temperatures
dropping into the upper 50s to low 60s in the higher elevations.
Meanwhile, daytime temperatures will range in the mid 80s across
the coastal and urban areas, and from the upper 70s to low 80s in
the higher elevations.

&&

.AVIATION...
(06Z TAFS)

.AVIATION... VFR durg prd. FEW clds nr FL025...FL040. SKC abv. Isold
SHRA ovr regional waters and en route btwn islands. Sfc wnds calm to
lgt/vrb, bcmg fm ESE 12-15kt with sea breeze variations aft 19/14Z.
L/Lvl wnds fm SE 15-20 kts BLO FL120. Few SHRA ovr ctrl and NW PR fm
19/18-19/22Z. No sig operational wx impact durg prd.

&&

.MARINE...

A surface high pressure extending from the far northeastern Atlantic
into the northeastern Caribbean will continue to generate moderate
east to southeast winds through late today. This will result in
light to moderate chops across the local waters. A surface low
pressure with its frontal boundary, moving eastward across the
western Atlantic, will approach the local islands by Wednesday into
Thursday. Gentle to moderate easterlies are expected on Tuesday,
becoming gentle and variable on Wednesday and early Thursday,
increasing from moderate to fresh out from the north Thursday into
Friday.

&&

.BEACH FORECAST...

Recent CariCOOS bouy network observations report seas below 4 feet
across the nearshore waters. Mariners can expect seas to remain
between 2 to 4 feet through Thursday, due to the arrival of a
surface low pressure and its associated frontal boundary.

The risk of life- threatening rip currents across all the islands
of Puerto Rico and the U.S. Virgin Islands is low. These
conditions will continue to persist until late Wednesday. By
Thursday, a moderate risk will return for the northern exposed
beaches of Puerto Rico, Culebra, Saint Thomas and Saint John.

[cycloneye]

ast Discussion
National Weather Service San Juan PR
357 AM AST Wed Feb 21 2024

.SYNOPSIS...

Unstable weather conditions are anticipated today as a surface low
pressure and its frontal boundary reach the local islands. There
is an increased chance for wetting rains today through early
Thursday. Afternoon showers and isolated thunderstorms are
expected across central and northern Puerto Rico. The U.S. Virgin
Islands will see the shower activity later in the afternoon and
early evening. Periods of heavy rain could lead to ponding of
water on roads and poor drainage areas along with the possibly of
minor urban flooding in isolated areas. Weather conditions will
improve by late Thursday into Friday.

&&

.SHORT TERM...Today through Friday...

Partly cloudy to variably cloudy skies prevailed across the region
overnight as a broad band of tradewind moisture continued to be
lifted up across the region. A line of showers embedded within this
cloudiness continue to move westward across the coastal waters
between the USVI and eastern Puerto Rico bringing periods of
moderate to locally heavy rains. Expect some of these showers to
reach portions of eastern PR during the early morning hours before
dissipating. Rainfall accumulations so far were less than a tenth of
an inch. The overnight low temperatures so far were in the mid-upper
70s along the coastal areas, and in the mid 60s to near 70 degrees
in the higher elevations and valleys. Winds were calm to light and
variable.

A surface high pressure ridge continued to extend southwards to just
northeast of the region from the central and northeast Atlantic,
while a low pressure system and associated cold front continued to
cross the west and southwest Atlantic. This pattern will create an
induced prefrontal trough across the region and fairly light east
southeast winds through early Thursday, as the trough and frontal
boundary approaches the region. The upper level ridge will continue
to erode and shift eastward as a polar trough deepens and approaches
from the west. Consequently as this pattern unfolds, expect
increasing instability aloft along with good low level moisture
convergence and pooling. The combination of the aforementioned
features will create unstable conditions aloft and good moisture
availability favoring a moderate to high potential for wetting rains
across the islands today through early Thursday.

Model guidance which continued to initialize fairly well suggesting
the best chance for enhanced shower activity and possible isolated
thunderstorm activity will be later today and through early Thursday
morning. This will be followed by rapid improvement and diminishing
cloud cover and shower activity by Thursday afternoon and Friday. By
then, a surface high pressure ridge will build across the west
Atlantic and winds will become more northerly, bringing in a drier
and more stable airmass with less potential for convective
development in and around the islands. Model guidance also suggests
that the high precipitable water values between 1.50-1.80 inches
today into Thursday is forecast to diminish to one inch or less by
Friday as winds become more northerly supporting cooler and more
seasonal temperatures and a fair weather pattern.

The greatest impact for the period will be the increased chance for
wetting rains today through early Thursday across the islands and
coastal waters. The best potential for enhanced afternoon showers
and isolated thunderstorms will be over the central interior and
northern half of Puerto Rico today then increasing later in the
afternoon and evening in and around the USVI, with the on and off
shower activity possibly lasting into early Thursday morning. The
expected periods of locally heavy rains may lead to ponding of water
on roads and poor drainage areas along with the possibly of minor
urban flooding in isolated areas. Brief wind gusts may accompany the
heavy downpours and thunderstorm activity later today and overnight
into Thursday.

&&

.LONG TERM...Saturday through Wednesday...

Moisture associated to the remnants of an old frontal boundary
and a trough is expected to arrive to the local area by Saturday
into Sunday. This will enhance showers and unstable conditions
throughout the region. As winds shift from the east to southeast,
the shower activity will affect mainly the eastern portions of
Puerto Rico and the U.S. Virgin Islands during the morning hours,
followed by afternoon convection across central and northwestern
Puerto Rico. Ponding of water is possible in lower elevations and
poor drainage areas. By late Sunday into Monday, a cold front will
approach the local area. Therefore, increasing the potential for
wetting rains. This wet pattern and unstable conditions will
extend through Tuesday. By Wednesday, stable conditions will
return. However, patches of moisture will continue to reach the
islands. The general wind flow will remain from the southeast and
then shifting form the east on Sunday. Easterly winds will prevail
for the rest of the long- term period. Seasonal temperatures are
expected to persist across Puerto Rico and the U.S. Virgin
Islands. Overnight temperatures will drop into the low to mid 60s
in the higher elevations, and from the upper 60s to low 70s in the
coastal areas. Daytime temperatures will range from the mid 80s
across the coastal and urban areas, to the upper 70s to low 80s in
the higher elevations.

&&

.AVIATION...
(06Z TAFS)

Prevailing VFR at all terminals but brief MVFR due to
SHRA/Low CIG with brief Mtn to Obscr ovr E PR til 21/12Z.
Isold TSRA ovr ctrl interior of PR and VCTY TJSJ/TJBQ fm 21/18-22Z
and USVI terminals 21/22Z-22/06Z. SCT-BKN clds nr FL025...FL050...
FL080. Isold-SCT SHRA ovr regional waters and en route btw islands
durg prd. Sfc wnds calm to lgt/vrb, bcmg fm E 8-12kt with sea breeze
variations and ocnly hir gusts aft 21/14Z. L/Lvl wnds fm E-SE 10-
15 kts BLO FL120.

&&

.MARINE...

A cold front that extends from Cuba to the coast of Panama will
continue to be pushed to the east through Wednesday before weakening
by Thursday in the eastern Caribbean. This will generate moderate to
fresh winds with the low spreading higher and possibly hazardous
seas into the local outer Atlantic waters on Thursday. Today, winds
will become variable. This will continue into early Thursday, and
then becoming moderate to fresh from the north later Thursday and
into Friday.

For beachgoers, there is a low risk of life-threatening rip
currents across all beaches of Puerto Rico and the U.S. Virgin
Islands.

&&

.FIRE WEATHER...

Variable weather conditions will prevail today across Puerto Rico
and the U.S. Virgin Islands due to the arrival of a surface low
pressure and its associated cold front. KBDI values are
unavailable at the the Cabo Rojo and Camp Santiago observations
sites. However, KBDI values in Guanica continue above the critical
threshold for fire danger. Winds are expected to remain below the
critical values from the northeast at 5 to 10 mph. Relative
humidity (RH) values could drop to the low 50s today. At this
moment, due to the expected conditions the fire danger risk should
remain low. Therefore, a Fire Danger Statement will not be issued
at this time. Users are advised to monitor further updates during
the day for any changes.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
342 AM AST Thu Feb 22 2024

.SYNOPSIS...
The combination of an area of low pressure north of the region
and associated frontal boundary and surface trough will maintain a
moist and unstable weather pattern at least into the early afternoon
hours. This along with an upper level trough crossing the region this
morning will aid in enhancing the morning and early afternoon shower
activity with still a chance of an isolated thunderstorms especially
over the local Atlantic waters. A gradual improvement is expected later
in the afternoon and through the evening as these features lift farther
north and east of the region. Thereafter a gradual improvement in the
overall weather conditions can be expected later today and through
Friday.

&&

.SHORT TERM...Today through Saturday...

Variable weather conditions under mostly cloudy skies prevailed
across the region during the overnight hours. A cold front is now
moving across the local islands, bringing bands of moderate to heavy
showers across sectors of northern Puerto Rico. Doppler radar showed
accumulations between 0.5 to 1.0 inches from Camuy to Vega Baja.
Overnight temperatures were observed in the mid 70s along the
coastal and urban areas, and in the mid 60s degrees in the higher
elevations. Winds were calm to light from the northwest.

Moderate to locally heavy showers will continue to move into the
area throughout the morning hours. Ponding of water in roads is
possible in lower elevations and poor drainage areas. The U.S.
Virgin Islands could observe shower activity during the morning
hours, with limited accumulations. Weather conditions are expected
to gradually improve during the afternoon hours. The latest model
guidance continues to show a building high pressure moving from the
western to central Atlantic. Winds from the north in response to the
high pressure will bring cooler-than-normal temperatures across the
region. A dry and stable weather pattern will prevail from Friday
into the weekend. Therefore, the potential for precipitation is low
and fair weather conditions will be observed.

&&

.LONG TERM...Sunday through Thursday...

Moisture associated to the remnants of an old frontal boundary
and an induced surface trough is forecast to return Sunday through
Monday, then merge with yet another cold frontal boundary on Tuesday
and Wednesday. This will again bring an increase in low to mid level
moisture convergence and instability aloft as another polar trough
is forecast to sweep across the region. Consequently, enhanced showers
with increased chance for isolated thunderstorms will be possible
at least through early Wednesday. Light to moderate east northeast
winds will prevail through Monday then becoming more easterly by
Tuesday. As the winds shift to a more easterly component, the shower
activity should then be focused mainly the eastern portions of Puerto
Rico and the U.S. Virgin Islands during the morning hours, followed
by afternoon convection mainly across the central interior and
northwestern Puerto Rico. Periods of isolated to scattered showers
can also be expected in and around the U.S. Virgin Islands during
that time. Ponding of water on roads and in poor drainage areas
as well as minor urban flooding will be possible through at least
early Wednesday morning. By late Wednesday and through Thursday,
improving conditions and diminishing cloud cover and shower activity
is so far expected, as a high pressure ridge will build aloft and
a surface high pressure ridge will move into the southwest Atlantic
and build across the region. This will result in a northeast wind
flow and stable conditions once again. However, occasional
patches of trade wind moisture may reach portions of the islands
from time to time but rainfall accumulations will not be
significant.

During the period, seasonal temperatures are expected to persist across
Puerto Rico and the U.S. Virgin Islands. Overnight temperatures will
drop into the low to mid 60s in the higher elevations and valleys,
and from the upper 60s to low 70s in the coastal areas. Daytime highs
will range from the mid 80s across the coastal and urban areas, to
the upper 70s to low 80s in the higher elevations.

&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions expected to prevail across all terminals through
the forecast period. An increase in TSRA/SHRA due to the passing of
a cold front may cause brief MVFR cigs across the local terminals
with Mtn top obscr ovr E interior of PR til 22/12Z. VCTS/VCSH expected
for the TJSJ/TIST/TISX terminals after 22/14Z. Afternoon TSRA/SHRA
development will result in VCTS/VCSH for TJPS between 22/13-22Z and
VCTS/VCSH for TJBQ between 22/15-21Z. Winds will continue from the
N-NW btw 10-15 kts with higher gusts after 22/14Z.

&&

.MARINE...

A weakening cold front and a pre-frontal trough will continue to
push eastward across the regional waters during the rest of today
while a surface high pressure ridge builds across the southwest
Atlantic waters. An area of low pressure north of the region will
also aid in generating moderate to locally fresh west to northwest
winds especially across the local Atlantic waters and passages. Choppy
an hazardous seas with isolated thunderstorms and occasional gusty winds
will therefore remain possible over the coastal and passages today.
On Friday, a high pressure system will develop and spread over the
western Atlantic. Winds will then become northeasterly and become
light to moderate thereafter and into the weekend.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Fri Feb 23 2024

.SYNOPSIS...
Weak mid to upper ridge will replace a departing upper trough which
will continue to lift north and east of the region, while a surface
high pressure ridge builds across the southwest Atlantic and north
of the area. This will create a west to northwest wind flow aloft
and light to moderate northerly winds in the low levels today, then
becoming more easterly by Saturday and Sunday with the approach of
an induced surface trough from the east. In the meantime a dry and
stable airmass will prevail today into early Saturday with increasing
moisture and unstable weather expected once again by late Saturday and
the rest of the upcoming weekend. Cool and pleasant seasonal temperatures
with light surface winds, and sea/land breeze variations are forecast
for today and into the weekend.

&&

.SHORT TERM...Today Through Sunday...

Mainly fair and dry weather conditions were observed across the islands
during the overnight hours. Winds prevailed from the north at 5 to 10
mph. Overnight temperatures were seen in the upper 50s to low 60s across
the higher elevations and in the mid 60s to low 70s across the coastal
and urban areas.

After the passage of a cold front across the region, a mass of dry
and stable air mass will dominate local weather today into tomorrow
Saturday. At this moment, rainfall is not anticipated across Puerto
Rico and the U.S. Virgin Islands. However, passing showers over the
waters cannot be ruled out. Northerly winds will prevail today, shifting
from the east-northeast later tonight. Cooler temperatures are forecast
today with daytime temperatures reaching the low 80s along the coastal
and urban areas, into the 70s across the higher elevations.

A moist airmass associated to the remnants of the cold front will approach
the area from the southeast by late Saturday into Sunday. The latest
Precipitable Water content Analysis (PWAT), show increasing values
from 1.30 to 1.60 inches. With the available moisture, there is an
increase in the chance of showers across the U.S. Virgin Islands and
eastern Puerto Rico during the morning hours, followed by afternoon
convective activity across portions of central and western Puerto
Rico. Another cold front, that is forecast to move off the eastern
coast of the Continental U.S. today, is expected to approach the
local area by late Sunday into Monday. Therefore, there is a potential
for wetting rains by the beginning of the upcoming workweek.


&&

.LONG TERM...Monday through Friday...

Pooling of moisture associated with the return remnants of an old frontal
boundary and an induced surface trough will merge with another cold
frontal boundary and lift across the region through Wednesday. This
will again bring an increase in low to mid level moisture convergence
and instability aloft as a short wave polar trough is forecast to sweep
across the region. Consequently, enhanced showers with a slight chance
for isolated thunderstorms will be possible at least through early
Wednesday. Light to moderate east northeast winds will prevail through
Monday then becoming more easterly by Tuesday. As the winds shift
to a more easterly component, shower activity should then be focused
mainly the eastern portions of Puerto Rico and the U.S. Virgin Islands
during the morning hours, followed by afternoon convection mainly across
the central interior and west to northwestern Puerto Rico. Periods
of isolated to scattered showers can also be expected in and around
the U.S. Virgin Islands during that time. Ponding of water on roads
and in poor drainage areas as well as minor urban flooding will
remain possible through at least early Wednesday. By late Wednesday
and through the rest of the period, a gradual erosion of moisture
is expected with improving conditions and diminishing cloud cover
and shower activity, as a strong high pressure ridge will build
aloft. This along with a surface high pressure ridge which will
move into the southwest Atlantic and build across the region will
result in a northeast wind flow and stable conditions once again.
However, occasional patches of trade wind moisture may reach portions
of the islands from time to time and this will aid in the development
of early morning showers and mostly isolated to scattered afternoon
showers. Significant rainfall accumulations are not anticipated during
the latter part of the period. So far the wettest period with excessive
rainfall impacts should be between Monday through early Wednesday morning
followed by a drying trend and lesser convection thereafter.

During the period, seasonal temperatures are expected to persist across
Puerto Rico and the U.S. Virgin Islands. Overnight temperatures will
drop into the low to mid 60s in the higher elevations and valleys,
and from the upper 60s to low 70s in the coastal areas. Daytime highs
will range from the mid 80s across the coastal and urban areas, to
the upper 70s to low 80s in the higher elevations.

&&

.AVIATION...
(06Z TAFS)
VFR conds are expected to prevail across all terminals during the
next 24 hrs. After the passage of a cold front surface winds from
the N will persist at all TAF sites through 23/14z. Then, winds will
become from the NNE btw 10-15 kts TJSJ/TJBQ/TIST/TISX terminals
after 23/13-14z, and from the ESE with land breeze variations at the
TJPS terminal after 23/14z. Winds will become light and vrb at 10
knots or less after 23/23z.

&&

.MARINE...
Only a few passing showers are possible at times over the regional
waters but mostly fair weather skies will prevail today into Saturday.
High pressure building across the southwest Atlantic and an area of
low pressure well northeast of the region will aid in maintaining
light to moderate north to northeast winds today and into the weekend.

For beachgoers, there will be a High Risk of Rip Currents for northern
Puerto Rico from Aguada to Carolina today due to a northwesterly swell
with breaking waves up to 7 feet possible. There is a moderate risk
for the remaining north facing beaches including the northern USVI
and a low risk for the southern coastal beaches including the islands
of St Croix.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Sat Feb 24 2024


.SYNOPSIS...

Expect the arrival of a moist airmass from the south today. This
airmass will increase the chance of showers across the islands.
Therfore, a wetter pattern should prevail from this weekend into
the middle part of the upcoming workweek. Cool and pleasant
seasonal temperatures with mostly light surface winds, and
sea/land breeze variations are forecast through the weekend.

&&

.SHORT TERM...Today through Monday...

Mostly clear skies prevailed overnight with a few tiny showers
appearing south of Saint Croix late in the night. The showers were
moving west northwest and most of them had not yet entered the
forecast area. Minimum temperatures so far ranged from the mid 50s
in the interior valleys to the mid 70s along the windward coasts.

The cold front that passed through the area on Wednesday is now
slowly returning from the southeast and is bringing some clouds and
better moisture with it. Precipitable water values of up to 1.75
inches are being seen about 100 miles south of our southern most
boundary which is at 17 degrees north. The GFS suggests that this
moisture will move over the area today and peak on Sunday during the
mid-afternoon hours. Although cloud cover is not heavy, and most of
the convection is completely capped by the inversion found between
5300 and 8200 feet, some shower activity over inland Puerto Rico is
likely this afternoon. Showers will increase through Sunday when
moisture peaks in the peak heating hours. Winds will not be
particularly strong which will allow local island effects to amplify
the inland convection. Wind flow at the surface will remain easterly
through today as a weak trough moves in from the east southeast. Its
passage later on Sunday will allow winds to turn southeast for a
brief period, but the arrival o a second front to just north of 20
degrees north latitude and the high pressure behind it will cause
the original northwest bound boundary to stall and allow it to merge
with the second front. This will keep moisture from decaying too
quickly and also allow a new influx of cooler air that will lower
temperatures from Saturday and Sunday.

Upper levels are active as well. A long wave trough and its
accompanying jet of over 100 knots will rotate through the western
Atlantic and push the high pressure deeper into the Caribbean. The
short wave moving through that trough will allow the tail of another
jet to brush the local area late on Monday which will further
prolong cloudiness and showers. As has been the case for much of our
dry season, the limiting factor on convective activity--meaning
showers and thunderstorms--has been the dryness of the mid levels.
Good moisture is expected to reach 600 mb on Sunday and this will
favor better amounts of rain--perhaps over 2 inches in local areas,
but at this time thunderstorms seem unlikely and have not been added
to the forecast for the short term period.

&&

.LONG TERM...Tuesday through Saturday...

The inherited forecast remains unchanged. At this time, models
continue to suggest that the moisture associated with the return
remnants of an old frontal boundary and an induced surface trough
will merge with another cold frontal boundary and lift across the
region through mid-week. Additionally, expect an increase in low
to mid-level moisture convergence and instability aloft as a
short-wave polar trough is forecast to move across the region.
Precipitable Water (PW) models now suggest values above the two
standard deviations for this time of the year. We anticipate
enhanced showers with a slight chance for isolated thunderstorms
for the first part of the short-term period, particularly through
at least early Wednesday. Currently, the forecast leans into a wet
pattern with light to moderate east-northeast winds through mid-
week. With this wind flow, showers will develop mainly in the
eastern portions of Puerto Rico and the U.S. Virgin Islands in the
morning hours, followed by afternoon convection, mainly across
west-southwestern sections of Puerto Rico. Ponding of water on
roads and in poor drainage areas, as well as minor urban flooding,
will remain possible through at least early Wednesday.

The weather conditions are foreseen to improve by late Wednesday
into the rest of the period. A gradual erosion of moisture is
expected with improving conditions and diminishing cloud cover and
shower activity as a strong high-pressure ridge will build aloft
on Thursday. A surface high-pressure ridge will also develop and
move into the southwest Atlantic and build across the region,
resulting in a northeast wind flow and the return of stable
weather conditions. However, occasional patches of trade wind
moisture may reach portions of the islands at times and will aid
in the development of early morning showers and mostly isolated to
scattered afternoon showers. Significant rainfall accumulations
are not anticipated through the weekend.

&&

.AVIATION...
(06Z TAFS)

VFR conds are expected to prevail across all terminals durg the next
24 hrs. However mstr from a diffuse cdfnt bndry returng to the area
is invading the FA fm the SE and will incr clds and SHRA. This will
likely bring brief MVFR to TISX bfr 24/21Z and SHRA ovr the NW quad
of PR aft 24/18Z with some MVFR arnd TJBQ and mtn topping ovr other
portions of PR. Winds will be easterly nr the sfc, but have already
turned S abv FL070. Winds will incrs to 10-15 kt aft 24/14Z with hir
gusts alg the coast. Max winds WSW 45-57 kt btwn FL260-450.

&&

.MARINE...
A surface high pressure ridge building across western Atlantic located
north of the region will aid in generating light to moderate
easterly winds today. Winds will then persist from the east to
northeast over the weekend as the high pressure ridge moves into the
central Atlantic. A small northwesterly swell will continue to
arrive and spread across the Atlantic waters today. An increase in
shower activity over the local waters is likely from Saturday night
through early next week as remnants from a frontal boundary moves
across the region.

&&

.BEACH FORECAST...
A High Risk of Rip Currents for northern Puerto Rico from Aguada
to Carolina will remain in effect through this afternoon due to
the swell with breaking waves around 6 feet. There is a moderate
risk for the remaining north facing beaches including the northern
USVI and a low risk for the southern coastal beaches including
the island of St Croix.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
507 AM AST Sun Feb 25 2024

.SYNOPSIS...

Expect the moist airmass to increase the chance of showers across
the islands today. Therefore, a wetter pattern should prevail
through the middle part of the upcoming workweek. Cool and
pleasant seasonal temperatures with mostly light surface winds,
and sea/land breeze variations are forecast for the next couple of
days.

&&

.SHORT TERM...Today through Tuesday...

Showers continued developing over night across the local waters with
some moving into Cabo Rojo and Lajas during the overnight hours
leaving as much as 1.68 inches in the last 12 hours according to a
raingage there. Some heavy showers also formed north and northeast
of San Juan over the nearshore Atlantic waters and the northern
portion of Luquillo, leaving 1 to 2 inches in the the heaviest
areas. Otherwise skies were partly to mostly cloudy over the area as
a band of scattered showers stretched SW-NE in a 75 mile wide band
across across Puerto Rico from the Mona Passage to north of Vieques.
Temperatures ranged from the mid 70s near the coasts to the upper
50s in the higher mountains.

High pressure in the central Atlantic waters were driving easterly
winds that turned southerly over the local area. This has pushed an
old frontal boundary into the area where it is stalling as a second
cold front about 500 miles northwest of San Juan (550 miles
northwest of Saint Thomas) was approaching the area. The GFS was
showing the moisture from the second front joining the old front
over the local area and prolonging the period of clouds, rain and
converging wind flow to beyond the short term period. The GFS still
shows precipitable water peaking today at around 21Z at about 1.9
inches and then slowly declining to 1.6 inches by the end of
Tuesday. At upper levels a long wave trough has been moving to the
east just north of the area with the best winds occurring this
morning at better than 60 knots and then again at close to 90 knots
as the trough from the second lobe of this wave moves through the
area on Tuesday at 12Z. Although widespread persistent heavy rains
are not expected, some areas may receive sufficient rain in a short
period of time to raise stream levels and create ponding of water on
roadways. Also some thunderstorms will be possible on Tuesday. These
rains will add significant amounts of water to the islands during
the period.

&&

.LONG TERM...Wednesday through Sunday...

The latest model guidance continues to suggest residual moisture
from the old frontal boundary and induced surface trough merging
with another cold frontal boundary lifting across the region
through Wednesday. At this time, models show mid-level
temperatures around -10 C by mid-week. With these weather
conditions and cold mid-level temperatures, we cannot rule out the
formation of some thunderstorm activity. Therefore, the forecast
leans toward a wet day with isolated thunderstorms. By late
Wednesday into Thursday, expect a gradual improvement in weather
conditions as a strong high-pressure ridge starts building aloft,
diminishing cloud cover and shower activity, especially on
Thursday. A surface high-pressure ridge will also develop and move
into the southwest Atlantic and build across the region, resulting
in a northeast wind flow and the return of stable weather
conditions. However, occasional patches of trade wind moisture may
reach portions of the islands at times and will aid in the
development of early morning showers and mostly isolated to
scattered afternoon showers. Precipitable Water (PW) models
suggest values dropping from above normal to around normal
climatological levels for this time of the year, late mid-week
into Saturday. Significant rainfall accumulations are not
anticipated during the long-term period. Nonetheless, by late
Sunday, expect a slight change in weather conditions as a trough
and a low-pressure system positions near the forecast area. Along
with these weather features, we anticipate the return of easterly
winds.

&&

.AVIATION...
(06Z TAFS)
Mstr is incrg ovr the FA with sct-num SHRA in a 75 mile wide band
that stretches SW-NE ovr PR from the Mona psg to N of Vieques. As
warming begins, conds will deteriorate and areas of MVFR/IFR with
mtn obscurations will commence. Most terminals will see only short
periods of MVFR however. Sfc winds generally less than 12 kt from
sea breezes. Gen flow will bcm northerly aft 25/16Z. Conds to impv
aft 26/03Z. Max winds W 55-65 Kt btwn FL360-420 incrg by 5-10 kt by
25/15Z.

&&

.MARINE...

Light to gentle easterly winds will continue today. Tonight, Winds
will increase to moderate and become more northeasterly, as a high
pressure ridge builds over the western Atlantic. An increase in
shower activity over the local waters is likely through early next
week as remnants from a frontal boundary moves over the region.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
531 AM AST Mon Feb 26 2024

.SYNOPSIS...
Issued at 436 AM AST Mon Feb 26 2024

Merging cold fronts over the area will provide ample moisture and
some convergence in northeasterly flow to hold clouds and showers
over the area until Wednesday. Then, some clearing and drying
will occur despite persistent quick passing showers. Moisture
returns on Monday and Tuesday. A long wave trough with colder air
aloft will generate some instability and the possibility of
thunderstorms on Tuesday and Wednesday.

&&

.SHORT TERM...Today through Wednesday...

Overnight, mostly cloudy skies prevailed across Puerto Rico and the
U.S. Virgin Islands. Showers began to develop over the Atlantic
waters and proceeded to move inland along the northeastern and
northern coast of Puerto Rico at night, leaving around 0.50 inches
of rain. Temperature-wise, they stayed in the low to mid-70s along
the coastal areas, while over the mountains, they stayed in the 60s.
The dominating wind flow was mostly light from the north-northeast.

The latest model guidance continues to suggest unstable weather
conditions throughout the first half of the workweek as the moisture
from the old frontal boundary merges with another cold frontal
boundary lingering across the forecast area. At this time,
Precipitable Water (PW) models show values above the 75th
percentile or above normal climatological levels for this time of
the year today. Therefore, the forecast for today leans into a wet
pattern across the islands. Despite the fact that persistent
widespread heavy rains are not expected, some areas could receive
sufficient rain during short periods, possibly raising stream
levels and causing ponding of water on roadways. Today, winds will
become east-northeasterly as high pressure continues to build
over the western Atlantic. This wind flow will allow the better
chance for rain to take place across northern, interior, and
southwest sections of Puerto Rico. From Tuesday into Wednesday,
the mid-level temperatures will become cooler at around -8 to -10
Celsius. Therefore, the potential for isolated thunderstorm
development increases, and for that reason, we added them to the
short-term forecast. A gradual improvement in weather conditions
is anticipated on Wednesday as a strong high-pressure ridge
starts building aloft, diminishing cloud cover and shower
activity. A surface high-pressure ridge will also develop and move
into the southwest Atlantic and build across the region,
resulting in northeasterly winds and the return of stable weather
conditions.

&&

.LONG TERM...Thursday through Sunday...

High pressure at the surface in the western Atlantic will be
refreshed later in the week with another high out of the eastern
United States. A persistent inverted trough that wanders between
55 and 45 degrees west longitude in the sub-tropical Atlantic will
also help to maintain northeasterly flow across Puerto Rico and
the U.S. Virgin Islands through the long term period. This will
bring cool and fairly moist air out of the central Atlantic in the
lower levels. Although mid levels will be dry, the persistent
winds of 10 to 20 knots and the abundance of low level moisture
will produce bands of showers that will bring night and early
morning showers to the U.S. Virgin Islands and the north and
northeast coastal sections of Puerto Rico and afternoon showers to
the southwestern and interior portions of Puerto Rico. Amounts
are not expected to be particularly heavy, but will help to
alleviate the drier periods of the previous week. Because of the
uniformity of the air flow during the period out of the cooler
central Atlantic temperatures will be in a slight cooling trend
overall, but will be warmest on the south coast.

At upper levels on Thursday and Friday, the atmosphere will
recover from the cold it caught during the passage of a long wave
trough Tuesday and Wednesday. We will begin to feel the effects
of a weaker short wave trough Saturday and Sunday.

&&

.AVIATION...
(06Z TAFS)
Issued at 436 AM AST Mon Feb 26 2024

VFR conditions across all terminals. However, TJSJ and TJBQ
terminals could experience brief MVFR conditions with SHRA after
26/14Z. Sfc winds will remain NE. After 26/14Z, winds will
increase to 12kt with sea breeze variations. Then, after 22Z,
expect winds to become light, 3-5 kts. Max winds W 60-70 kts btwn
FL395-455.

&&

.MARINE...
Issued at 436 AM AST Mon Feb 26 2024

Seas will be generally gentle with moderate short period wave
action due to persistent northeast flow. A pulse of swell from a
low moving northeast out of the western Atlantic will reach the
area today and tonight, but more significant wave action will be
generated by local winds Friday through Sunday when small craft
advisories will likely be necessary in the local outer Atlantic
waters.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
506 AM AST Tue Feb 27 2024

.SYNOPSIS...
Issued at 432 AM AST Tue Feb 27 2024

Late Wednesday high pressure in the western Atlantic will push
away the moisture from the stalled fronts that merged together
over the local area. But, in the meantime conditions will be wet
today and Wednesday with the most rain expected today. Cooler air
and stronger winds from Thursday onward will keep temperatures
from warming very much from the additional sunshine. Moisture will
begin to return over the weekend.

&&

.SHORT TERM...Today through Thursday...

Overnight, partly cloudy skies and northeasterly winds prevailed
across the islands. Like previous days, lines of showers developed
over the Atlantic waters and then moved inland along the northern
and interior municipalities of PR, Culebra, and Saint Thomas. Some
showers also formed over the Anegada Passage and then filtered over
the island of Saint Croix. The accumulations with this rainfall
activity were around 0.30 to 0.70 inches. Based on radar estimates,
narrow spots in the municipality of San Juan received around 1.00
inches of rain. Temperature-wise, they stayed in the low to mid-70s
along the coastal areas, while over the mountains, they stayed in
the 60s once again.

Today, the forecast leans to wet and unstable weather conditions as
moisture from a frontal boundary and a pre-frontal trough lingers
across the region. The latest model guidance suggests the best
moisture over Puerto Rico and the U.S. Virgin Islands today.
Precipitable Water (PW) models also show PW content around the 75th
percentile, or above normal climatological levels for this time
of the year. Additionally, the temperatures at the mid-levels
remain cool at around -8 to -11 Celsius. Therefore, there is an
increased potential for isolated thunderstorm development, and for
that reason, they were added into the short-term forecast through
mid-week. Today, the main risk over the islands is that some
areas could receive sufficient rain during short periods,
raising stream levels and causing water to pond on roadways. At
this time, we foresee this weather pattern continuing through
early Wednesday.

By late Wednesday into Thursday, expect a gradual improvement in
weather conditions across Puerto Rico and the U.S. Virgin Islands as
a strong high-pressure ridge starts building aloft, diminishing
cloud cover and shower activity. A surface high-pressure ridge will
also develop and continue building across the region, resulting in
northeasterly winds and the return of stable weather conditions.

&&

.LONG TERM...Friday through Monday...

High pressure at the surface in the western Atlantic will be
refreshed on Friday with another high out of the eastern United
States. A persistent inverted trough that wanders between 40 and
52 degrees west longitude in the sub-tropical Atlantic will also
help to maintain northeasterly flow across Puerto Rico and the
U.S. Virgin Islands through the long term period. This will bring
cool and fairly moist air out of the central Atlantic in the lower
levels. Although mid levels will be dry, the persistent winds of
10 to 20 knots and the abundance of low level moisture will
produce bands of showers that will bring night and early morning
showers to the U.S. Virgin Islands and the north and northeast
coastal sections of Puerto Rico and afternoon showers to the
southwestern and interior portions of Puerto Rico. Amounts are not
expected to be particularly heavy, but will continue to add
moisture to the soils and streams. Because of the uniformity of
the air flow during the period out of the cooler central Atlantic
temperatures will be fairly steady from day to day, but will be
warmest on the south coast.

At upper levels on Thursday and Friday, the atmosphere will
recover from the cold it caught during the passage of a long wave
trough today and Wednesday as high pressure builds over the
Caribbean. We will begin to feel the effects of a weaker short
wave trough Saturday night through Monday.

&&

.AVIATION...
(06Z TAFS)
Issued at 432 AM AST Tue Feb 27 2024

VFR conditions across all terminals. However, most terminals could
experience brief MVFR conditions with SHRA and VCTS after 27/14Z.
Sfc winds will remain NE. After 27/14Z, winds will increase to 8-
12kt with sea breeze variations and ocnl higher gusts after
27/16Z and around SHRA. Then, after 22Z, expect winds to become
light, 2-6 kts. Maximum winds W 65-75 kt btwn FL325-465.


&&

.MARINE...
Issued at 432 AM AST Tue Feb 27 2024

Seas will remain somewhat choppy with 3-5 foot waves except in the
areas protected from the persistent northeast winds. Winds will
increase to 15 to 20 knots across the area beginning on Friday and
a northerly swell will arrive to make seas hazardous by Friday
night with little improvement in seas through the middle of next
week.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
536 AM AST Wed Feb 28 2024

...New SYNOPSIS, AVIATION, MARINE...

.SYNOPSIS...
Issued at 447 AM AST Wed Feb 28 2024

A stalled frontal boundary over the area will fade and drift south
today through Friday. Shallow showers will continue in
northeasterly flow through the weekend with another increase in
moisture during the first part of next week.

&&

.SHORT TERM...Today through Friday...

During the overnight hours, mostly cloudy skies prevailed across
the islands once again. Over the northern and eastern sections of
Puerto Rico, clouds and showers dominated the forecast area as
moisture from a frontal boundary continued to linger across the
region. A little after midnight, a moderate to strong shower moved
over the vicinity of San Juan, leaving around 0.30 to 0.70 inches
of rain. Nonetheless, the strongest rainfall and thunderstorm
activity stayed over the Atlantic waters, where Marine Weather
Statements were issued. The islands of Saint Thomas and Saint John
also experienced some rain, but it was not significant as the
accumulations were around 0.01 inches. The temperatures
throughout the night stayed in the low 70s along the coastal
areas, while over the mountains, they stayed in the 60s once
again.

Today, expect the wet and unstable weather conditions to prevail
through the first half of the day. The latest model guidance
suggests the upper trough axis will move across the islands from
12-15Z or before mid-day. Precipitable Water (PW) models also show
PW content around the 75th percentile or above normal
climatological levels for this time of the year. However, we
forecast PW values to drop gradually to 1.30 inches later in the
day which are around normal climatological levels. The
temperatures at the mid-levels remain cool at around -11 Celsius,
meaning the potential for isolated thunderstorm development
remains. For that reason, we will continue to hold thunderstorms
in the forecast today. By the afternoon, weather conditions will
begin to improve across the islands gradually. Nonetheless, there
is a limited rainfall risk for Puerto Rico, meaning that there is
a potential for water ponding on roads and poorly drained areas,
as well as flooding in urban and small streams.

On Thursday, a high-pressure system will form at the surface over
the western Atlantic, along with a ridge that will build aloft,
diminishing cloud cover and shower activity. These weather
features will allow northeasterly winds and stable weather
conditions to continue through the end of the workweek.
Regardless of the anticipated improvement in weather conditions,
occasional trade wind showers cannot be ruled out.

&&

.LONG TERM...Saturday through Tuesday...

High pressure at the surface in the western Atlantic will build
through Saturday evening as it moves eastward. It will also extend
deep into the eastern Caribbean. A persistent inverted trough
will hold around 50 degrees west longitude through Monday morning
and then move over the local area in a much weaker state. Flow at
the surface will gradually veer from northeast to east and then at
the very end, east southeast. Temperatures overall are expected to
warm beginning Saturday as feed around the low decreases, but
increasing moisture and the passage of a second upper level trough
will limit that warming Monday and Tuesday. This will bring
generally fair weather punctuated by passing showers Saturday and
Sunday followed by a somewhat wetter pattern.

&&

.AVIATION...
(06Z TAFS)
Issued at 447 AM AST Wed Feb 28 2024

VFR conditions across all terminals. TJSJ and TJBQ could
experience brief MVFR conditions with SHRA and VCTS after 28/14Z.
Some mtn topping is expected. Sfc winds will remain NE. After
28/14Z, winds will increase to 8- 14kt with sea breeze variations
and ocnl higher gusts after 28/16Z and around SHRA. Then, after
22Z, expect winds to become light, 3-8 kts. Maximum winds WSW
81-86 kts btwn FL350-405.

&&

.MARINE...
Issued at 447 AM AST Wed Feb 28 2024

Seas will be generally quiet from 3 to 5 feet except in the outer
Atlantic waters where seas up to 6 feet may occur. These are
being generated by winds of 12 to 18 knots. Beginning on Friday a
weak northerly swell and stronger wind waves will cause Atlantic
waters to become hazardous with some seas reaching 7 to 8 feet
over the weekend with occasional seas up to 9 feet. Seas are
expected to subside Monday and Tuesday.

.BEACH FORECAST...
Issued at 447 AM AST Wed Feb 28 2024

As seas and northerly swell begin to grow on Friday, the risk of
rip currents on beaches with northerly exposure, will go from
moderate to high.