Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
447 AM AST Thu Jan 16 2025

.SYNOPSIS...

Patches of clouds and showers are expected today across the
islands, as the remnants of an old frontal boundary continue to
arrive into the region. Pulses of a long-period northerly swell
will continue to arrive and reach the regional waters today
Therefore, hazardous marine conditions and life-threatening rip
currents will continue until early next week.

&&

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

Variably cloudy skies, along with passing showers, were observed
across the eastern and northern portions of the CWA throughout the
night. Aside from slippery roads and minor ponding of water in
localized areas, rainfall accumulations were not significant.
Weather stations also reported breezy northeasterly winds, with some
areas experiencing wind gusts of 20-25 mph during the night.
Additionally, stations recorded lows in the mid to upper 70s across
coastal areas and in the low to mid-60s across the highest mountains
and valleys.

Satellite imagery shows a broad band of cloud cover across the
northeastern Caribbean, associated with a shearline and remnants of
a front located southeast of the forecast area. Northeasterly
steering winds will continue to steer patches of clouds and showers
across the islands, particularly during the morning hours. Localized
areas in northeastern Puerto Rico may face a limited flooding threat
during this time. Drivers are urged to exercise caution, as slippery
roads could create hazardous conditions. Additionally, patchy fog
will persist in mountainous regions and valleys during the early
morning, adding to driving difficulties with reduced visibility.
During the afternoon hours, isolated showers may develop across
southwestern portions of Puerto Rico, though rainfall accumulations
are not expected to be significant.

For the remainder of the short-term forecast, low to mid-level
moisture is expected to surge as a frontal boundary northwest of the
area and the aforementioned shearline gradually converges over the
northern Caribbean. Precipitable water values could approach 1.9
inches, well above the the percentile of the climatological
normal for this time of year. Upper-level dynamics will also
become slightly more favorable, completely eroding the inversion
cap as the mid-level ridge shifts northeast of the region and a
shortwave trough at upper levels moves eastward over the forecast
area, promoting cold air advection aloft. Model guidance suggests
that the most favorable region of the trough will remain north of
the CWA. However, other indicators, such as a drop in 500 mb
temperatures, changes in 250 mb height fields, and steeper 850–700
mb lapse rates, point to some favorable conditions for at least
shallow convection.

For the morning hours, expect a cool advective pattern with patches
of cloud and shower activity across northern and eastern portions of
Puerto Rico and the smaller islands. The highest probability of
shower activity is anticipated on Friday night and Saturday morning.
During the afternoon, showers may develop across the interior and
western/southwestern Puerto Rico, driven by sea breeze convergence
and local effects. However, the highest flooding threat is expected
during the night and morning hours across northeastern Puerto Rico,
though it will remain limited for both days.

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

A slightly wet pattern is expected by the beginning of next week
with an upper-level weak shortwave trough crossing the region on
Sunday. Light to moderate shower activity is anticipated with a
30- 50% chance of rain, mainly over portions of eastern Puerto
Rico and the U.S. Virgin Islands during the morning hours. The
latest precipitable water content model guidances suggest values
up to 1.5 inches on Sunday. On Monday, the precipitable water
values are expected to drop into 1.0 inch as a mid-level ridge
establishes near the region and promoting drier air and stability
over the islands.

With the mid-level ridge establishing over the region, seasonal
weather conditions will predominate for the rest of the long-term
period. Patches of moisture moving into the area from the east
will result in light to moderate showers during the morning across
the windward portions of the islands. In the afternoon hours,
this activity will be observed over the interior and central
Puerto Rico with minimal accumulations. With this weather
scenario, significant rainfall accumulations are not expected.

A warmer trend is in the vicinity with above-than-normal
temperatures this upcoming weekend into early next week due to the
influence of east southeast winds. However, seasonal temperatures
will return as winds shift more from the east by mid-week. values
this weekend into early next week. Daytime highs are expected to
reach the mid 80s in coastal and lower elevations, while the
mountains will experience highs in the mid to upper 70s.

&&

.AVIATION...

(06Z TAFs)

Mainly VFR conditions are expected to prevail across all terminals
during the next 24 hours. However, remnants of a front will continue
to promote VCSH/SHRA and BKN cigs btw FL020-FL050 thru the period.
Intermittent periods of MVFR conditions are anticipated. Mount obsc
will prevail throughout the period. NE winds expected to continue
in general between 10-15 kt with stronger gusts at times.

&&

.MARINE...

High pressure building across the western Atlantic will support
moderate to fresh northeasterly trades through the rest of the
workweek. Pulses of a long-period northerly swell will continue to
reach the regional waters through today maintaining hazardous
marine conditions. By Friday into the rest of the weekend,
another pulse of a northerly swell is forecast to arrive across
the Atlantic waters.


&&

.BEACH FORECAST...

The long-period northerly swell is expected to continue creating
hazardous coastal conditions along the coastal areas. These
conditions will pose significant risks for coastal activities. The
northern and northwestern coasts face a High Risk of Rip
Currents, with breaking waves ranging from 8 to 11 feet and
occasionally higher at least until 6 PM on Thursday. There is also
a High Surf Advisory in effect for the northern and northwestern
coast of Puerto Rico, Culebra, St. Thomas, and St. John. Breaking
waves up to 10 to 12 feet will lead to dangerous surf conditions,
potentially causing coastal erosion and localized flooding in
vulnerable areas.

Residents and visitors in affected regions should heed warnings,
avoid swimming in these waters, and stay informed about updates from
local authorities.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
402 AM AST Fri Jan 17 2025

.SYNOPSIS...

The remnants of an old frontal boundary will arrive later today
into Saturday, promoting instability and wetter conditions across
Puerto Rico and the U.S. Virgin Islands. Periods of with moderate
to locally heavy showers are likely mainly over portions of
northern and northeastern Puerto Rico. Pulses of a long-period
northerly swell will promote life- threatening rip currents over
the next few days, with hazardous marine conditions returning
later today. Residents and visitors are encouraged to follow
closely the weather conditions if planning to go to "Las Fiestas
de la Calle San Sebastian" or the local beaches over the weekend.

&&

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

The night remained fairly calm, with clear to partly cloudy skies
prevailing for the most part. A few showers were observed over the
regional waters but stayed offshore throughout most of the period.
Similar weather conditions are expected during the day today.
Overnight lows ranged from the mid to upper 70s in eastern coastal
areas, the low 70s across western coastal areas of Puerto Rico, and
the low to mid-60s in the highest mountains and valleys, as recorded
by weather stations.

Satellite data indicates a frontal boundary just northwest of Puerto
Rico, which is expected to approach the region today. As it merges
with the remnants of an older frontal boundary, moisture levels will
increase to above-normal values. This surge in moisture, combined
with reduced stability caused by a weakening mid-level ridge
shifting northeastward and the presence of some troughiness aloft,
will result in a noticeable uptick in the frequency of showers. The
wettest period is expected late tonight through early Saturday
morning, with moderate to locally heavy showers likely. During this
time, wind speeds will also increase, resulting in showery
conditions, especially across the northern and eastern coastal areas
of Puerto Rico and the smaller islands. By Saturday afternoon,
additional shower development is possible over the interior and
western portions of Puerto Rico, driven by local effects.

As the mid-level ridge rebuilds later in the short-term forecast
period, increased stability aloft will likely reduce the frequency
of showers. However, sufficient low-level moisture will remain to
support isolated to scattered showers on Sunday morning, primarily
light to moderate in intensity and confined to coastal areas. These
showers are not expected to pose any flooding threat.

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

The upcoming workweek will begin with drier and stable weather
conditions across the local islands as pockets of drier air filter
into the region from the east. The latest precipitable water content
analysis suggest values to remain between normal to below-normal
(1.0 to 1.2 inches) throughout the period. However, periods of
isolated to scattered showers are anticipated as small patches of
moisture moves into the area at times.

At the mid-levels, a strong mid-level ridge will establish over the
region promoting drier air and stability aloft. At the surface, a
dominating surface high pressure in the central Atlantic will
promote an easterly wind flow through Wednesday. With the
aforementioned weather scenario, limited showers activity is
expected through the latter part of the week.

As the surface high pressure migrates from the central to eastern
Atlantic, winds will begin to shift from the southeast. Under this
pattern an increase in precipitable water is expected with values up
to 1.6 inches. By late Wednesday into Thursday, an upper-level low
is expected to migrate east of the islands and promoting unstable
conditions through the rest of the period. With this environmental
setting, isolated to scattered showers are likely over eastern
Puerto Rico and the U.S. Virgin Islands during the morning hours
and over the interior in the afternoon.

A warmer trend continues for the long-term weather outlook with
above-than-normal temperatures to remain for several days. Daytime
highs are expected to reach the mid to upper 80s in coastal and
lower elevations, while the mountains will experience highs in the
mid to upper 70s.

&&

.AVIATION...
(06Z TAFs)

Mainly VFR conditions are expected to prevail across all terminals
during the next 24 hours. However, a frontal boundary will move over
the area today increasing SCT-BKN lyrs near FL025...FL040...FL080
with Isold-WDLY SCT SHRA across northern terminals of PR and USVI
aft 17/20z. NE/ENE winds increasing to 10-15 kt with higher gusts
and sea breeze variations aft 17/14z. Winds will continue to
increase aft 18/00z to 15-20 kt and higher gusts as the frontal
boundary settles ovr the area.

&&

.MARINE...

High pressure building across the western Atlantic will support
moderate to locally fresh northeasterly trades through today. Winds
will turn more easterly during the weekend. Another pulse of a
northerly swell is forecast to arrive across the Atlantic waters
today and lingering through the weekend. This swell will promote
hazardous seas and small craft advisory conditions once again.

&&

.BEACH FORECAST...

Pulses of long-period northerly swell will continue to pose
significant risks for coastal activities this weekend. The
northern and northwestern coasts face a High Risk of Rip Currents,
with breaking waves ranging from 6 to 8 feet and occasionally
higher. At this moment there is no High Surf Advisory in effect,
but we will continuously monitor seas during the day to see if
conditions warrant.

Residents and visitors in affected regions should heed warnings,
avoid swimming in these waters, and stay informed about updates from
local authorities.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
407 AM AST Sat Jan 18 2025

.SYNOPSIS...

The merging of two old frontal boundaries will continue to
promote showers across the northern and northeastern portions of
Puerto Rico, and the U.S. Virgin Islands today. However, a drier
airmass will establish north of the area next week promoting fair
weather across the islands. Pulses of a long-period
northerly swell will promote hazardous marine conditions and life-
threatening rip currents over the weeknight. A High Surf Advisory
is now in effect through at least 6 PM AST Saturday due to large
breaking waves between 10 and 13 feet.

&&

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

As expected, the merging of two old frontal boundaries increased the
frequency of showers across the forecast area. A line of moderate to
heavy showers developed early in the night over the coastal Atlantic
waters, with the edge occasionally brushing the northern coastal
regions of Puerto Rico. However, the onset of the land breeze
prevented the line of showers from moving inland, keeping most of
the activity offshore throughout the night. Radar rainfall estimates
indicated that, at most, less than an inch of rain accumulated
across the northern and eastern coastal municipalities of Puerto
Rico, Vieques, Culebra, and the northern U.S. Virgin Islands. Gusty
winds were also reported at night, with wind speeds increasing as
the frontal boundaries converged. Weather stations, particularly in
north coastal areas of Puerto Rico near the strong line of showers,
recorded wind gusts of up to 30 mph. Low temperatures ranged from
the low to mid-70s across coastal areas and from the mid to upper
60s in the mountainous regions of Puerto Rico.

This weather pattern will persist through the morning hours, likely
affecting more land areas as the land breeze weakens. Additionally,
above-normal moisture and marginal instability aloft, caused by a
weak shortwave trough passing through, will continue to erode the
inversion cap that has been present throughout the week. This will
allow localized, shallow convection to develop and intensify through
the morning hours and early afternoon. As a result, a limited
flooding threat is expected during this period, primarily across the
northern and eastern third of Puerto Rico.

For the remainder of the short-term forecast, gusty easterly trade
winds will continue to bring patches of moisture associated with
remnants of the old frontal boundaries across the region. Moisture
values will remain near to slightly above normal, particularly
across windward sections of the islands, while southern Puerto Rico
may experience lower moisture levels. Additionally, a mid-level
ridge will rebuild, reinforcing subsidence, increasing dry air
aloft, and re-establishing the trade wind inversion cap. This setup
will suppress overall convective development; however, brief trade
wind showers are still expected, enhanced by sea and land breeze
interactions and other local effects. As a result, variable weather
conditions will prevail, with a mix of clouds and showers in areas
of higher moisture, alternating with periods of fair weather and
clear skies in drier patches of air moving through the region.

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

The long-term weather outlook remains unchanged, with only few
changes in timing and location of the weather features. For the
first half of the period, a mid-level ridge is expected to promote
drier air intrusion and stability over the islands. During this
period limited shower activity is anticipated with only 10-30%
chance of rain mainly over portions of northeastern and western
Puerto Rico, and the U.S. Virgin Islands. At the surface, a high
pressure system dominating in the central Atlantic will promote
easterly winds on Tuesday. Winds are expected to shift from the
southeast by late Wednesday into Thursday as the surface high
moves towards the eastern Atlantic. Moving into the latter part of
the week, the weather conditions will become more unstable due to
the presence of an upper level low in the northeastern Caribbean.
By Thursday into Friday, an increase in shower activity is likely
over the region with above-normal precipitable water values up to
1.7 inches. By Saturday, weather conditions will improve, once
again, over the area. Fair weather conditions will return,
accompanied with southerly winds and moist air.

Warm temperatures will return next week into the islands. Above-
normal temperatures are expected to persist for several days,
affecting mostly the coastal and urban areas or the islands.
Daytime highs are expected to reach the mid to upper 80s and low
90s in coastal and urban areas, while the mountains will
experience highs in the mid to upper 70s.

&&

.AVIATION...
(06Z TAFs)

Mostly VFR at all terminals. SCT ocnl BKN lyrs nr FL025...FL050 en
route btw PR and the USVI with SCT -SHRA/SHRA associated with
moisture remnants of old frontal boundary carried by prevailing ENE
trade winds. SFC wnds 5-10 kts and variable with land breezes bcmg
fm E-NE 12-18 kts with sea breeze variations aft 18/14Z and higher
gusts.

&&

.MARINE...

High pressure building across the western Atlantic will support
moderate to locally fresh east to northeast trades today. Winds will
turn more easterly later today into early next week. Another pulse
of a northerly swell will continue to spread across the Atlantic
waters and local Caribbean passages this weekend. This swell will
promote hazardous seas and small craft advisory conditions once
again.

&&

.BEACH FORECAST...

Pulses of long-period northerly swell will continue to pose
significant risks for coastal activities throughout the weekend.
A High Surf Advisory is now in effect through at least 6 PM AST
this evening due to large breaking waves between 10 and 13 feet
along the northwest to northeast coast of Puerto Rico, Culebra,
and the northern U.S. Virgin Islands. Residents and visitors in
affected regions should heed warnings, avoid swimming in these
waters, and stay informed about updates from local authorities.

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
438 AM AST Sun Jan 19 2025

.SYNOPSIS...

Breezy to windy condtions will continue for the next several days
as a strong surface high pressure builds over the central
Atlantic. Quick passing showers embedded in the trades will move
at times across the USVI and eastern sections of PR. Limited
shower activity is expected each afternoon over western PR. Choppy
wind- driven seas will maintain hazardous marine conditions
throughout the workweek.


&&

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

Calm and breezy conditions prevailed during the overnight hours
across the region. Isolated showers were observed across the eastern
and northern portions of the islands, leaving minor accumulations.
Breezy conditions were observed too, with easterly winds at 8 to 14
mph, and higher gusts at times. Minimum temperatures remained in the
low to mid 60s in the mountains and higher elevations, and in the
mid to upper 70s along the coastal areas and lower elevations.

At the mid to upper levels, a building ridge is expected to promote
stability over the islands. Therefore, limiting the potential to
observe strong showers across the region. At the surface, a strong
high pressure over the central Atlantic will continue to maintain
breezy easterly trade winds at 15 to 25 mph, with higher gusts.
During the next few days, patches of moisture will reach the islands
from the east dragged by the winds. However, no significant rainfall
is expected during this period.

Over the next few days, warmer temperatures will return. The 925 mb
temperatures will remain between normal to above-normal. This trend
is expected to persist until at least next weekend, affecting mostly
the coastal and urban areas of the islands. Therefore, expect highs
to reach the mid to upper 80s and low 90s along the coastal areas
and lower elevations, and from the mid to upper 70s in the mountains
and higher elevations.

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

The mid-to upper-level ridge will continue to support stable
conditions aloft and a strong trade wind cap across the
northeastern Caribbean, as it drifts slowly eastward from the
central to eastern Atlantic by the end of the long-term period.
However, the stronger trades will bring at times the remnants of
old frontal boundaries across the local area. Promoting passing
showers in general across the windward areas of the islands, and
limited afternoon shallow convection over western PR. Global model
guidance suggest a weak upper level-low developing over the
central Caribbean on Thursday, and merging with a stronger upper
level-trough over the western Atlantic during the weekend. This
weather scenario can support better shower development on Thursday
and late in the weekend.

Normal to above normal temperatures will prevail for most of the
long-term period, particularly across the coastal and lower
elevations of the islands. Daytime highs are expected to reach the
mid to upper 80s and low 90s in coastal and urban areas, while the
mountains will experience highs in the mid to upper 70s. Minimum
temperatures will range from the low 60s across the higher
elevations to the mid and upper 70s across the lower elevations of
the islands.


&&

.AVIATION...

(06Z TAFs)

Mainly VFR conditions are expected to prevail across all terminals
during the next 24 hours. Passing SHRA expected to continue today
across TJSJ/TIST/TISX. E winds expected to continue in general
between 15-20 kts with stronger gusts at times.


&&

.MARINE...

A high pressure building across the western to central Atlantic will
support moderate to fresh easterlies for the next several days.
Stronger winds are expected on Tuesday across the Anegada Passage and
Caribbean waters. Choppy wind-driven seas will continue across
portions of most offshore waters and passages. Small craft advisory
conditions are likely to continue through the entire forecast
period.


&&

.BEACH FORECAST...

Fading northerly swell and windy conditions across the region
will continue to promote life-threatening rip currents,
especially along the eastern and northern coasts of Puerto Rico
and the U.S. Virgin Islands through today. Thereafter, a moderate
risk of rip currents is expected to persist for the next couple of
days, before winds and seas increase once again the breaking wave
action by midweek along the eastern and northern coastlines.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Mon Jan 20 2025

.SYNOPSIS...

Strong trades will continue through midweek across the eastern
Caribbean. Showers embedded in the trades will favor the windward
areas of the islands. Shallow afternoon convection is possible
each afternoon over western PR. Shower activity is expected to
increase in general between Tuesday afternoon and early Thursday
morning. Hazardous seas due to wind-driven waves will persist for
most of the workweek.


&&

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

Mostly fair weather was seen across the region with passing showers
from moderate to locally heavy along windward sections and local
waters. Stations along interior and eastern portions reported
rainfall accumulations up to 0.20 inches. Minimum temperatures
remained in the low and mid 70s along urban and coastal areas
while the interior reported low to mid 60s.

Trade winds will prevail for the short term forecast, as a surface
high pressure builds in the Central Atlantic, promoting breezy
conditions across the local islands. Model guidance keeps suggesting
the arrival of trade wind perturbations into the region, seeing the
wettest period on Tuesday. Compared to climatology, above normal
Precipitable Water (PWAT) values (1.5 - 1.8 in), an increase in the
700-500 mb moisture content, and steeper lapse rates in the low
levels exhibit an increase of shower activity with moderate to
locally heavy showers across the region each day, particularly over
interior and eastern portions of Puerto Rico, including the San Juan
Metropolitan Area. Although deep convection activity is not
anticipated, rainfall accumulations will increase flooding potential
in the forementioned areas. Ponding of water in roadways, urban, and
poorly drained areas is very likely, with a slight chance of
isolated urban and small stream flooding.

Seasonal temperatures are expected during the short-term period.
Maximum temperatures will range from mid 80s to upper 80s in lower
elevations while higher terrains can expect mid 70s to low 80s.


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

A deep layered ridge will continue to move slowly eastward from
the central to the eastern Tropical Atlantic through the long-term
period. This will promote moderate to locally fresh trades across
the eastern Caribbean and occasionally bring remnants of old
frontal boundaries across the local area, resulting in passing
showers primarily in the windward areas of the islands. Limited
shower activity is expected over western Puerto Rico. However, the
overall coverage and intensity of showers could increase on
Thursday and Sunday.

Global model guidance suggests that a weak upper-level low or
trough will develop over the central Caribbean on Thursday and
merge with a stronger upper-level trough over the western Atlantic
during the weekend. This scenario will likely support increased
shower activity on Thursday with the arrival of the remnants of an
old frontal boundary from the east and later in the weekend as a
front over the western Atlantic approaches the region and a pre-
frontal trough develops near the islands.

Normal to above-normal temperatures are expected to prevail
throughout most of the long-term period, particularly in the
coastal and lower elevations of the islands. Daytime highs will
range from the mid to upper 80s and low 90s in coastal and urban
areas, while the mountains will experience highs in the mid to
upper 70s. Minimum temperatures will range from the low 60s in the
higher elevations to the mid and upper 70s in the lower elevations
of the islands.


&&

.AVIATION...

Mostly VFR conds expected along TAF sites. Showers embedded in the
trades will promote VCSH at most terminals btw 20/12z-20/22z.
Trade winds from 15-20 kt with gusts up to 25-28 kt during
daytime, decreasing to 5-10 kt winds under land breeze influence
will prevail after 20/22z.


&&

.MARINE...

A high pressure building across the central Atlantic will support
moderate to fresh easterlies for the next several days. Stronger
winds are expected from tonight through Tuesday across the
Caribbean waters and local passages. Choppy wind-driven to
hazardous seas for small craft will continue across portions of
most offshore waters and passages. Small craft advisory conditions
are likely to continue through the end of the workweek.


&&

.BEACH FORECAST...

A moderate risk of rip currents is expected to persist for the
next couple of days. The wind-driven seas will increase once
again risk of rip currents during the second part of the workweek
along the eastern and northern coastlines of the islands.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
435 AM AST Tue Jan 21 2025

.SYNOPSIS...

Breezy to locally strong winds will continue across the region
through midweek. Quick passing showers are expected to move from
time to time over the USVI and eastern sections of PR. Shallow
afternoon convection is possible each afternoon over western PR,
with no significant impacts. Shower activity is expected to
increase in general between late today and early Thursday
morning. Choppy wind-driven to hazardous seas will persist for
most of the workweek, maintaining dangerous conditions for small
craft and creating life-threatening rip currents.


&&

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

A calmer night and breezy conditions along coastal areas were
observed over the forecast area, with pockets of moisture moving
over the local waters. Seasonal minimum temperatures prevailed, with
urban and coastal areas stations reporting mid to upper 70s and
higher terrains remained in the 60s.

Variable weather and breezy conditions are expected for the short-
term forecast, as a surface high pressure builds in the Central
Atlantic, promoting strong trade winds across the region. The latest
guidance suggests an increase in moisture content in low to mid
levels, but not as much as yesterday's 00z runs. A mid-to-high level
ridge over Hispaniola and breezy conditions will inhibit deep
convection activity through the period. Today, the weather pattern
will most likely be like yesterday with showers embedded in the
trades, from moderate to locally heavy, mainly along windward
sections. However, the latest model guidance suggests the arrival of
another trade perturbation is expected tomorrow morning, moving
across the region. Rainfall accumulations will likely increase
flooding potential during the night, particularly over eastern
Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands. Ponding
of water in roadways, urban, and poorly drained areas is highly
likely, along with isolated urban and small streams flooding. A
drier air mass will reach the local islands later on Thursday
morning, bringing stable conditions once again.

There's a tendency for 925 mb temperatures to increase up to above-
normal values due to low-level winds shifting from the ESE.
Maximum temperatures are expected from mid 80s to low 90s mainly
along urban and coastal areas and the interior may expect mid 70s
to low 80s.

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

A deep layered ridge will hold over the Tropical Atlantic through
the long-term period. A short-wave trough is expected to cause a
brief weakness over the region from Sunday onwards, and a pre-
frontal trough is expected to develop mainly north of the region
during the weekend. However, the precipitable water content is
forecast to remain at normal to below normal levels, and showers
across the area will be driven mostly by the remnants of old
frontal boundaries that the trade winds will carry from time to
time.

Normal to above-normal temperatures are expected to prevail
throughout most of the long-term period, particularly in the
coastal and lower elevations of the islands. Daytime highs will
range from the mid to upper 80s and low 90s in coastal and urban
areas, while the mountains will experience highs in the mid to
upper 70s. Minimum temperatures will range from the low 60s in the
higher elevations to the mid and upper 70s in the lower elevations
of the islands.


&&

.AVIATION...

(06z TAFs)

VFR conds expected for all terminals. E-ENE winds with 10-18 kt and
gusty winds up to 25 kt from 21/12z through 21/22z. VCSH for TIST
and TISX due to the arrival of another trade perturbation
embedded in the trades.


&&

.MARINE...

Building surface high pressure across the central Atlantic will
support moderate to fresh easterlies for the next several days. A
wind surge today will promote stronger winds across the Caribbean
waters and local passages. Choppy wind-driven to hazardous seas
for small craft will continue across portions of most offshore
waters and passages. Small craft advisory conditions are likely
to continue through the end of the workweek. Showers will increase
from late today through early Thursday morning across the
regional waters.


&&

.BEACH FORECAST...

Choppy wind-driven seas across the Atlantic and eastern coastlines
of the islands will promote a high risk of rip currents through
midweek. A High Rip Current risk continues in effect across northern
Puerto Rico, Culebra, and St Croix. Life-threatening rip currents
are still possible elsewhere.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Wed Jan 22 2025

.SYNOPSIS...

Shower activity is expected to increase in general through early
Thursday morning due to a trade wind perturbation. Choppy wind-
driven to hazardous seas will persist for most of the workweek,
maintaining dangerous conditions for small craft and promoting
life-threatening rip currents. Quick passing showers are expected
to move from time to time over the USVI and eastern sections of
PR. Shallow afternoon convection is possible over western PR each
day.


&&

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

Mostly fair weather, and breezy conditions, were observed overnight
with passing showers embedded in the trades along eastern portions
of Puerto Rico and the U.S. Virgin Islands. Doppler radar rainfall
estimates ranged from 0.1 to 0.2 inches, with local amounts up to
0.3 inches over Rio Grande. Minimum temperatures in lower elevations
remained in the 70s while higher terrains were observed in the lower
to mid 60s.

The short term forecast remains on track, with a variable weather
pattern for the second part of the workweek. Current satellite image
shows patches of moisture arriving into the region, and derived
products show high moisture content over east of the Leeward
Islands. The broad high surface pressure in the Central Atlantic
continues promoting trade winds, which will remain for the next few
days. A mid-to-high level ridge northeast of the region will
maintain stable conditions aloft, unfavoring convection activity.
The perturbation in the trades is expected to arrive later today,
increasing PWAT values will increase up to 1.8 inches, above normal
values based on the latest model guidance and climatology. This will
promote frequent shower activity, from moderate to locally heavy,
across the region, particularly starting today in the afternoon into
Thursday morning. Rainfall accumulations over the eastern,
eastern interior, and the San Juan Metropolitan Area in Puerto
Rico, Vieques, Culebra, and the U.S. Virgin Islands. Although
showers will move quickly, ponding of water in roadways, urban,
and poorly drained areas is very likely, along isolated urban and
small streams flooding. A drier air mass will arrive on Thursday,
but patches of moisture will arrive bringing occasional showers.

Low-level winds shifting from the E-ESE will promote above-normal
925 mb temperatures today, with maximum temperatures in lower
elevations from mid 80s to upper 90s, and higher terrains from mid
70s to low 80s.

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

A deep-layered ridge is expected to presist over the Tropical
Atlantic throughout the long-term period. A short-wave trough is
expected to cause a brief weakness aloft over the region on
Sunday, and a pre-frontal trough is expected to develop mainly
north of the region during the weekend. Another upper level trough
is expected to move over the area on Tuesday, and the 500 mb
temperatures are forecast to drop near -7C. However, the
precipitable water content is forecast to remain at normal to
below normal levels through the entire forecast period, and
showers across the area will be driven mostly by the remnants of
old frontal boundaries that the trade winds will carry from time
to time.

Normal to above-normal temperatures are expected to prevail
throughout most of the long-term period, particularly in the
coastal and lower elevations of the islands. Daytime highs will
range from the mid to upper 80s and low 90s in coastal and urban
areas, while the mountains will experience highs in the mid to
upper 70s. Minimum temperatures will range from the low 60s in the
higher elevations to the mid and upper 70s in the lower elevations
of the islands.


&&

.AVIATION...

(06z TAFs)

Mostly VFR conds expected at TAF Sites. Perturbation in the trades
will arrive today, with -RA/+RA for TISX, TIST starting at 22/13z
and for TJSJ at 22/22z. Reduced CIG/VIS may promote brief periods of
MVFR conds from 22/18z to 23/06z. E-ESE winds from 8-12 kt and
gusty winds up to 20 kt.


&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to locally fresh easterlies for the next several days.
Choppy wind-driven to hazardous seas for small craft will continue
across portions of most local waters and passages. Small craft
advisory conditions are likely to continue through the end of the
workweek. Increased shower activity will continue through early
Thursday morning.


&&

.BEACH FORECAST...

A high risk of rip currents is in effect for the north oriented
beaches of Puerto Rico, as well as for Culebra and easternmost
Vieques. A moderate risk of rip currents is in effect for most
other areas. Choppy wind-driven seas will continue to promote up
to a high risk of rip currents through the end of the week.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
520 AM AST Thu Jan 23 2025

.SYNOPSIS...

A weak surface trough crossing the region will continue to promote
shower activity across the islands through the rest of the
morning hours, before a drier air mass fills in from the east
later this afternoon. Trade wind perturbations will continue to
move from time to time during the next few days, promoting an
advective pattern with showers moving over the USVI and eastern
sections of PR during the night. Choppy wind-driven to hazardous
seas will persist for the rest of the week, maintaining dangerous
conditions for small craft and promoting life-threatening rip
currents. An induced surface trough is expected to move over the
area on Sunday.


&&

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

Rainfall activity persisted overnight along northern/eastern Puerto
Rico, Vieques, Culebra, the U.S. Virgin Islands, and local waters.
The 00z sounding showed an increase of moisture content in the lower
levels, with PWAT values of 1.63 inches, compared to the 12z values
(1.29 in). Additionally, satellite-derived products show above-
normal values across the region, as the perturbation in the trades
arrived overnight. Doppler Radar rainfall estimates from 0.2 to 0.5
inches over north-central and eastern Puerto Rico. Rain gauges over
the aforementioned areas reported 0.1 - 0.9 inches while St. Croix
reported up to 0.5 inches of precipitation.

A variable weather pattern will prevail for the latter part of the
workweek into the weekend. The surface high pressure in the Central
Atlantic will linger for the next few days, promoting strong trade
winds. The mid-to-high level ridge northeast of the region will
continue to support stable conditions aloft. PWAT values will
decrease once again as a drier air mass will move across the area
today, and strong trade winds will promote breezy conditions.
However, above-normal values are expected later tonight and early on
Friday, as another perturbation in the trades moves across the
region, bringing light to moderate showers mainly over eastern
Puerto Rico, Vieques, Culebra, and the USVI. Ponding of water in
roadways, urban, and poorly drained areas is likely. This pattern
will repeat on Friday into Sunday, with mostly fair conditions
during the day and occasional passing showers overnight.

The combination of E-ESE low-level winds, above-normal 925 mb winds,
and high moisture content will bring above climatological normal
temperatures today. Max temperatures in urban and coastal areas are
expected from mid to upper 80s with localized areas observing low
90s. Interior sections will most likely observe temperatures in the
mid to upper 70s.

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

A deep-layered ridge is expected to persist over the Tropical
Atlantic throughout the long-term period. However, a TUTT induced
surface trough is expected to reach the area from the east on
Sunday, increasing shower activity through early Monday morning.
An upper level trough is expected to move over the area on
Tuesday, and the 500 mb temperatures are forecast to drop near
minus 7C, increasing instability aloft. However, the precipitable
water content is forecast to remain at normal to below normal
levels(under 1.25 inches) during the first part of the workweek,
but increasing to normal to above normal levels (1.50-1.75 inches)
by Thursday as another low-level trough develops over the eastern
Caribbean.

Normal to above-normal temperatures are expected to prevail
throughout most of the long-term period, particularly in the
coastal and lower elevations of the islands. Daytime highs will
range from the mid to upper 80s and low 90s in coastal and urban
areas, while the mountains will experience highs in the mid to
upper 70s. Minimum temperatures will range from the low 60s in the
higher elevations to the mid and upper 70s in the lower elevations
of the islands.


&&

.AVIATION...

(06z TAFs)

VFR conditions are expected for all terminals. VCSH for most
terminals due to the arrival of another perturbation with showers
embedded in the trades starting around 23/22z. Breezy conditions btw
23/12z - 23/22z with E-ESE winds btw 10-15 kt and gusty winds up to
25 kt.


&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to locally fresh easterlies for the next several days.
Choppy wind-driven to hazardous seas for small craft will continue
across portions of most local waters and passages. Small craft
advisory conditions are likely to continue through the end of the
week for some offshore areas.


&&

.BEACH FORECAST...

A High Rip Current Risk remains in effect for the northern and
eastern beaches of PR, Culebra, and St. Croix through the end of
the workweek. A pulse of a small long-period northwesterly may
extend the areal coverage of the life-threatening rip currents to
Rincon and Aguada on Friday.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Fri Jan 24 2025

.SYNOPSIS...

Breezy trade winds will bring occasional patches of cloud and
showers across the islands, resulting in quick passing showers,
especially over the windward locations. Life-threatening rip
currents will likely form along the north and east-facing beaches
in PR and the USVI. Maximum temperatures are expected from mid to
upper 80s in lower elevations while higher terrain may expect mid
to upper 70s.

&&

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

Breezy conditions and shower activity persisted overnight, as
another perturbation in the trades moved across the region. Based on
Doppler Radar estimates, portions of the southeastern were the most
affected with estimates from 0.2 to 0.5 inches with localized areas
around 0.75 inches. Some stations along the area reported
accumulations of 0.64 inches in Caguas and 0.81 inches in Cayey.

An advective pattern, with a mixture of breezy stable conditions and
periods of shower activity embedded in the trades, will prevail for
the short-term forecast. The broad surface high pressure lingering
in the Central Atlantic continues promoting strong trade winds.
Current satellite imagery shows another perturbations in the trades
moving near the Leeward Islands and the latest model solutions agree
that these perturbations will arrive in the region each day
overnight, bringing light to moderate showers mainly over eastern
Puerto Rico and the USVI. Sunday is most likely the wettest day of
the period, as PWAT values suggested by model guidance increase to
above climatological normals (1.5 - 1.6 in). Additionally, the
latest model guidance suggests an increment in moisture content in
the 700-500 mb layer, as the mid-to-high level ridge moves eastward,
pushed by a polar trough exiting eastern CONUS. Although flood
potential is low, ponding of water in roadways, urban, and poorly
drained areas is very likely.

Strong trade winds will continue throughout the forecast period,
promoting breezy conditions across the region. Maximum temperatures
are expected from mid to upper 80s in lower elevations while higher
terrain may expect mid to upper 70s.

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

The ridge aloft will begin to feel an approaching TUTT around
Sunday, weakening the deep-layered ridge across the Northeast
Caribbean. The TUTT will swing by the region between Monday and
Tuesday when instability could increase. Then, another ridge
pattern aloft will build over PR and the USVI between Wednesday
and Thursday. We noted the possibility of having a mid to upper-
level trough northeast of us, over the Central Atlantic, that
could interact with the ridge aloft on Friday. Regardless of these
upper-level patterns, the dominant weather feature is a strong
surface high pressure across the North Atlantic that modulates
local weather conditions. This surface high pressure will maintain
any frontal boundary that could move from the Eastern Seaboard
into the western Atlantic away from us. On the other hand, the
surface high will promote breezy to locally windy trade winds
throughout the long term, pushing occasional moisture surges
across the islands, especially across the windward portions of
PR/USVI.

Model guidance suggests that Precipitable Water will increase
from near-normal to above-normal values from Wednesday onward,
mainly due to a perturbation or low pressure (observable around
700 MB and below) that could be enhanced by low-level convergence
across the windward locations. This could promote showery weather
throughout the second part of the following workweek.

&&

.AVIATION...
(06z TAFs)

Mainly VFR conds will prevail for all TAF Sites. E-ESE winds from 10-
15 kt and gusts up to 25 kt starting near 24/14z at most terminals.
VCSH for TISX near 24/12z. Another perturbation arriving later
today will promote VCSH for TIST, TJSJ, and TJBQ.

&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to fresh easterlies for the next several days. A long-
period northwesterly swell combined with choppy wind-driven seas
will result in hazardous seas for small craft across portions of
most the local waters and passages. Therefore, Small Craft
Advisory conditions are expected to continue throughout the day.

&&

.BEACH FORECAST...

Life-threatening rip currents will likely develop along the north
and east-facing beaches in PR, Culebra and St Croix due to the
combination of fresh to locally strong easterly winds and the
arrival of a long-period northwesterly swell. As a result, a High
Rip Current Risk statement is in effect through at least early
Saturday morning.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Sat Jan 25 2025

.SYNOPSIS...

Today will be a sunny day with the arrival of patches of clouds
that may result in some showers here and there. Be careful along
the north and east-facing beaches, where life-threatening rip
currents are likely today. The breeze trades will continue to pool
enough moisture across the islands, resulting in quick passing
showers, especially over the windward locations on Monday and
around Wednesday through Friday.

&&

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

Overnight calm and fair weather conditions prevailed across Puerto
Rico and the U.S. Virgin Islands. Temperature-wise, they remained in
the low to mid-70s along the coastal/urban areas, and over the
mountainous/rural areas, they stayed in the 60s. Winds were
relatively easterly, around 5 to 10 mph.

Today, stable weather conditions will prevail, with periods of light
showers embedded in the trade winds. As mentioned in a previous
discussion, trade winds, driven by a broad surface of high pressure
over the Central Atlantic, will continue to dominate the region,
promoting somewhat breezy conditions today. Maximum temperatures
will range from the mid to upper 80s in lower elevations and the mid
to upper 70s in the higher terrain. This weather pattern may suggest
that people do outdoor activities, but it is worth mentioning that
beach and marine conditions are not favorable for people to be on
the north and east-facing beaches of Puerto Rico and Culebra or for
small craft operators to be in the offshore Atlantic Waters.

A change in weather conditions is expected by Sunday onwards as a
wetter pattern is expected to develop as another perturbation in the
trades brings increased moisture. The latest model guidance suggests
precipitable water values increasing to above climatological normals
for this time of the year with values around 1.5 inches. With this
change, we forecast more frequent light to moderate showers across
eastern Puerto Rico, the U.S. Virgin Islands, and surrounding
waters. Temperature-wise, they will remain in the mid to upper 80s
for lower elevations and mid to upper 70s for higher elevations on
Sunday.

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

Instability will increase in response to a short wave trough at
upper levels and a low at mid-levels on Tuesday. This will be
followed by a more stable atmosphere Wednesday through Friday as a
mid-to-upper-level ridge builds over the Northeast Caribbean.
Then, we expect a trough amplifying from the Northeast near us by
Saturday, enhancing instability near the archipelago.

Meanwhile, a surface high pressure centered across the Central
Atlantic will keep away a frontal boundary (moving eastward across
the Western Atlantic) from PR and USVI. Its associated pre-frontal
trough will position off to the northwest of PR. However, the
breezy trade winds will promote the arrival of moisture, resulting
in occasional periods of showery weather on Wednesday and Friday.
Moisture will slowly erode around late Friday through Saturday
before the frontal boundary moves closer to the islands by the
weekend, as another high pressure builds behind it over the
Western Atlantic.

&&

.AVIATION...
(06z TAFs)

VFR conds should prevail across all TAF Sites. E winds from 6-15 kt
and gusts up to 20 kt starting near 25/14z at most terminals.
An increase in shower activity is forecast to arrive later today,
promoting VCSH for TIST, TJSJ, and TJBQ.

&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to fresh easterlies for the next several days. A long-
period north-northwesterly swell combined with choppy wind-
driven seas will result in hazardous seas for small craft across
portions of most the local waters and passages. Although
conditions will somewhat improve across the coastal waters today,
further deterioration due to increasing seas and winds will
return around midnight tonight. Therefore, Small Craft Advisory
conditions are expected to continue throughout the weekend.

&&

.BEACH FORECAST...

Life-threatening rip currents will likely develop along the north
and east-facing beaches in PR, Culebra and St Croix due to the
combination of fresh easterly winds and pulses of a lingering
northwesterly swell. As a result, a High Rip Current Risk
statement continue in effect.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
442 AM AST Sun Jan 26 2025

.SYNOPSIS...

Calm weather is expected this morning, with an increase in rain
activity anticipated for the afternoon and evening. Increasing
atmospheric instability interacting with pockets of moisture will
lead to occasional showers in windward areas early this week.
While stability will decrease by the middle of the week, low-level
moisture may still contribute to the formation of showers.
Additionally, there is an increasing likelihood of breezy to
locally windy trade winds from Friday afternoon through next
weekend.

&&

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

Overnight, mostly cloudy skies and light to moderate rainfall
prevailed across Puerto Rico and the U.S. Virgin Islands. Winds were
easterly with a slight northeasterly component, ranging from 7 to 15
mph, which allowed showers to move quickly through the region.
Rainfall accumulations remained below 0.70 inches. The persistent
cloud cover kept temperatures in the mid to upper 70s along coastal
and urban areas, and in the upper 60s to low 70s over mountainous
and rural areas.

Recent satellite imagery shows slightly drier air beginning to
filter into the region during the morning hours today. However, the
latest model guidance continues to indicate that precipitable water
values will remain near or slightly above normal for this time of
year, around 1.5 inches. By the afternoon hours, another easterly
perturbation along with the available moisture will enhance
rainfall, particularly over the eastern half of Puerto Rico, the
U.S. Virgin Islands, and surrounding waters. Winds are expected to
remain breezy, ensuring that showers will move quickly through the
area. However, localized ponding of water on roads and in poorly
drained areas is possible where the heaviest or most frequent
rainfall occurs. Maximum temperatures will range from the mid to
upper 80s in lower elevations and the mid to upper 70s in higher
terrain. Overall, most of the rainfall is expected over the
Caribbean waters this afternoon, though some showers may reach the
eastern sections of Puerto Rico.

As mentioned in previous discussions, an approaching tropical upper
tropospheric trough (TUTT) will begin to influence the region by
Monday, increasing atmospheric instability. Combined with the
moisture present from the surface to mid-levels, this will support
the continuation of variable weather conditions, with breezy trade
winds pooling moisture across the islands. This will lead to passing
showers, especially in windward areas. Winds will remain easterly
due to a surface high-pressure system situated over the central to
eastern Atlantic.

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

A mid-to-upper-level ridge building over the Northeast Caribbean
from Wednesday through Friday will promote a stable atmosphere.
However, a surface high pressure across the Central Atlantic,
inducing an easterly wind flow with a lingering frontal boundary
northwest of PR, will favor moisture pooling across the islands.
Under the aforementioned weather pattern, we expect a typical
weather pattern with the arrival of scattered showers across the
local waters and windward portions in PR and the USVI, where low-
level convergence could enhance this activity, becoming numerous
at times.

Late Friday night into the weekend, model guidance suggests a
trough amplifying from the Central Atlantic near the Northeast
Caribbean, weakening the ridge pattern and enhancing the formation
of trade wind perturbations that will occasionally arrive across
the USVI and PR.

Meanwhile, another surface high pressure, building and moving
eastward from the Western to Central Atlantic, will enhance the
trade winds, increasing the potential to observe another period of
breezy to locally windy trades from late Friday into Sunday.

&&

.AVIATION...
(06z TAF)

All TAF sites should experience VFR conds. E winds from 7-15 kt and
gusts up to 25 kt starting near 26/14z at most terminals.
An increase in shower activity is forecast to arrive this afternoon,
promoting VCSH for TIST, TJSJ, and TISX.

&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to fresh easterlies for the next several days. As a result,
choppy to hazardous wind-driven seas continue across most of the
local waters and passages. Therefore, Small Craft Advisory conditions
are expected to continue through early this week.

Another surface high pressure forecast to move eastward from the
Western Atlantic to the Central Atlantic will promote fresh to
locally strong northeast to easterly winds, extending the
hazardous marine conditions the second part of the week.

&&

.BEACH FORECAST...

Exercise caution along the north and east-facing beaches of PR,
Culebra and St Croix, as we have a High Risk of observing life-
threatening rip currents today. Elsewhere, we have a moderate risk
of rip currents due to fresh easterly winds and choppy confused
seas.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
439 AM AST Mon Jan 27 2025

.SYNOPSIS...

Life-threatening rip currents will continue to impact the north
and east-facing beaches of Puerto Rico and the US Virgin Islands.
Increasing atmospheric instability interacting with a pocket of
moisture will lead to occasional showers in windward areas early
this week. While instability will decrease by the middle of the
week, low-level moisture may still contribute to the formation of
showers. Additionally, there is an increasing likelihood of breezy
to locally windy trade winds from Saturday onward.

&&

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

During the night, cloudy skies with light to moderate rainfall were
observed across the eastern half of Puerto Rico and the U.S. Virgin
Islands, while the western half of Puerto Rico experienced clear to
partly cloudy conditions. Rainfall accumulations ranged from 0.30 to
0.60 inches. The persistent cloud cover kept temperatures in the mid
to upper 70s in coastal and urban areas and in the upper 60s to low
70s in mountainous and rural regions. As has been typical, easterly
winds of around 10 mph were present, occasionally stronger near
areas of rainfall.

The latest model guidance suggests an increase in instability and
higher precipitable water content as the tropical upper tropospheric
trough (TUTT) approaches the region today. Precipitable water values
are expected to fluctuate between normal and above-normal levels for
this time of year. The combined influence of the TUTT and abundant
moisture will lead to variable weather conditions, bringing an
increase in shower activity throughout the day. While no significant
flooding risks are expected, localized ponding on roads and in
poorly drained areas remains likely. Maximum temperatures are
forecast to reach the mid to upper 80s in lower elevations and the
mid to upper 70s in higher terrains. Overnight lows will range from
the 70s to 60s. Winds are expected to remain breezy with an easterly
flow today, becoming lighter by Tuesday.

By Wednesday, a mid-to-upper-level ridge will build over the
Northeast Caribbean, promoting a more stable atmosphere. However,
the surface high-pressure system over the Central Atlantic and a
lingering frontal boundary northwest of Puerto Rico will promote
moisture pooling across the islands. This combination of weather
features will bring a typical pattern of scattered showers,
particularly along the local waters and the windward sides of Puerto
Rico and the U.S. Virgin Islands.

.LONG TERM...Thursday through Monday

With a TUTT-low across the Central Atlantic and a mid to upper-
level high pressure across the Northeast Caribbean, we can predict
an increase in induced trade wind perturbations reaching PR and
the USVI during the second part of the workweek. The interaction
of a surface high across the eastern Atlantic and a migrating high
over the western Atlantic will keep a frontal boundary to linger
off to the northwest of PR, pooling moisture over us. Under this
weather pattern, we can anticipate the arrival of trade wind
perturbation each day. Although the timing of the arrivals of
these perturbations shows some inconsistency between model
guidance runs, they will definitely affect the region.
Additionally, low-level convergence will enhance rain activity
over the windward locations. Although periods of sunshine
(daytime) or clear skies (nighttime) can be anticipated, showery
weather will affect the region occasionally.

It is essential to mention that although the western portions of
PR can expect fair weather overnight and during the mornings,
local effects may produce afternoon showers that could extend into
the early evening hours each day.

As the frontal boundary dissipates, the surface high pressure
will build strongly over the Atlantic Ocean, tightening the local
pressure gradient. Subsequently, this will promote the return of
the breezy to locally windy trades from Saturday onward.

&&

.AVIATION...
(06z TAFs)

VFR conds across all TAF sites. E winds from 10-17 kt and gusts up
to 25 kt starting near 27/13z at TJSJ, TIST, and TISX. Showers will
continue to filter across the islands throughout the day, with VCSH
or -RA affecting most TAF sites. while there is no risk of
flooding caused by rain, some water ponding on roads may still
occur.

&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to fresh easterlies for the next several days. As a result,
choppy to hazardous wind-driven seas continue across most of the
local waters and passages. Therefore, Small Craft Advisory conditions
are expected to continue through early this week. Another strong high
pressure will promote fresh to locally strong winds by the upcoming
weekend.

&&

.BEACH FORECAST...

Please, exercise caution along the north and east-facing beaches
of PR, Culebra and St Croix due to a High Risk of observing life-
threatening rip currents. Elsewhere, we have a moderate risk of
rip currents due to fresh easterly winds and choppy confused seas.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
411 AM AST Tue Jan 28 2025

.SYNOPSIS...

Expect a mixture of sunshine and clouds throughout this morning,
followed by afternoon showers across the windward locations and
northwest PR. A trade wind perturbation will bring a sharp
increase in moisture around Thursday. A weather pattern,
consisting of occasional showers across the windward locations of
PR/USVI, followed by afternoon showers across PR's western and
interior portions will prevail throughout the forecast. We still
have a moderate risk of rip currents along the north and east-
facing beaches in PR and the USVI. Near to above-normal
temperatures or a warming trend will likely prevail through the
workweek. While instability will decrease by midweek, low-level
moisture embedded in the trades will still lead to occasional
showers. Additionally, there is a growing likelihood of breezy to
locally windy trade winds starting on Saturday.

&&

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

Overnight, mostly calm weather conditions prevailed across Puerto
Rico and the U.S. Virgin Islands. While early evening showers passed
through the eastern sections of Puerto Rico, they only accumulated
between 0.10 to 0.30 inches of rain. The western half of Puerto
Rico, like in previous days, remained with clear skies. Temperatures
in the lowlands stayed in the mid to upper 70s, and the higher
elevations ranged from the upper 60s to low 70s. Easterly winds
persisted at 7 to 15 mph.

The tropical upper tropospheric trough (TUTT) will continue to cross
the region through tonight, slightly enhancing instability and
increasing moisture levels to around 700mb. Precipitable water
models indicate values fluctuating between normal and above normal
for this time of year. Nevertheless, the combination of these
weather features along with the occasional introduction of
patches of dry air will result in variable weather conditions.
Locally induced afternoon showers are expected over the western
parts of Puerto Rico today. Maximum temperatures are forecast to
reach the upper 80s in the lower elevations and the mid to upper
70s in the higher terrains. Winds are anticipated to gradually
decrease throughout the day.

By mid-week, a mid-to-upper-level ridge will build over the
Northeast Caribbean, leading to a more stable atmosphere. However, a
surface high-pressure system over the Central Atlantic and a frontal
boundary northwest of Puerto Rico will help promote moisture pooling
across the region. This combination will bring a typical weather
pattern of scattered showers, primarily along the local waters and
the windward sides of Puerto Rico and the U.S. Virgin Islands.
Additionally, low concentrations of Saharan dust will reach the
islands, affecting air quality and potentially impacting those with
respiratory conditions. As we move toward Thursday, conditions could
shift, bringing an increase in rainfall activity by late afternoon
or evening.

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

A TUTT-low amplifying near the Lesser Antilles will weaken the
mid to upper-level high-pressure ridge across the Northeast
Caribbean. This TUTT will induce surface perturbations, reaching
PR and the USVI Friday onward. While at the surface, high pressure
will migrate from the Western to the Central Atlantic, tightening
the local pressure gradient and inducing a breezy to windy
pattern from late Friday through Tuesday next week. Under this
weather pattern, we can anticipate the arrival of trade winds
perturbations each day, bringing periods of showery weather as
they will be enhanced by low-level convergence.

Model guidance continues to have inconsistencies with the timing
of these perturbations' arrivals, causing a moderate-high
uncertainty about when we can expect those periods of scattered to
numerous showers. However, they will affect the region at times.
Thus, expect a mixture of sunshine (daytime) and mostly clear
skies (nighttime) with some clouds and quick showers, followed by
afternoon showers across the western sections of PR.

&&

.AVIATION...
(06z TAFs)

VFR conditions will prevail across all TAF sites. However,
showers may cause brief MVFR conditions at TJBQ after 28/16Z with
expected -RA VCSH. E winds at 10-15 kt after 28/13Z, with
occasionally higher gusts near the heaviest rainfall activity.
VCSH affecting TJSJ, TISX, and TIST after 28/14Z.

&&

.MARINE...

A surface high pressure across the central Atlantic will support
moderate to fresh easterlies for at least tonight. As a result,
choppy to hazardous wind-driven seas will continue across most of
the local waters and passages. Therefore, the Small Craft Advisory
was extended through this afternoon for the Atlantic Offshore Waters,
elsewhere small crafts should exercise caution. Another strong high
pressure will promote fresh to locally strong winds by the upcoming
weekend.

&&

.BEACH FORECAST...

Please, exercise caution along the exposed beaches in PR and the
USVI as we still have a moderate risk of life-threatening rip
currents due to fresh easterly winds and choppy confused seas.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
440 AM AST Wed Jan 29 2025

.SYNOPSIS...

A variable weather pattern will hold for the upcoming days, with
presence of moisture today and Saharan Dust air Layer for
Thursday. Shower activity is forecast each day for the afternoon
hours across the western interior sections and eastern sections of
Puerto Rico & the U.S. Virgin Islands. Marine conditions are
forecast to deteriorate by Friday due to confused seas.


&&

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

Mostly clear skies prevailed across the islands, with the exception
of the eastern coastal areas of Puerto Rico, where some clouds and
showers filtered across. The overnight temperatures in the lowlands
stayed in the 70s, and the higher elevations in the 60s as mostly
clear skies dominated the region. Easterly with a northeasterly
component persisted with wind speeds ranging from 2 to 8 mph.
Overall, calm weather conditions dominated Puerto Rico and the U.S.
Virgin Islands.

The latest model guidance continues to suggest a mid-level ridge
building over the Northeastern Caribbean, leading to a stable
atmosphere today. However, climatological models show precipitable
water values fluctuating from the 50th to the 75th percentile or
normal to above-normal values for this time of the year, and
humidity values extending from the surface to around 700mb. Meaning
that there is high confidence in shower development throughout the
day. At this time, the forecast leans towards afternoon convergence,
with periods of moderate to heavy rain developing across the
interior and western sections of Puerto Rico as winds will become
lighter and variable today. Therefore, there is a limited risk of
flooding in those areas, particularly during the afternoon hours.
Occasional brief passing showers are anticipated across the eastern
sections of Puerto Rico and the U.S. Virgin Islands. Late today into
tomorrow, low concentrations of Saharan dust will move over the
islands, affecting air quality and potentially impacting those with
respiratory conditions.

On Thursday, expect a cut-off low to approach the forecast area and
winds to become moderate to fresh northeasterly as a frontal
boundary and subsequent surface high influence the region. The
combination of these weather features will promote moisture pooling
across the region.

As we move toward Friday, we anticipate a slight
increase in rainfall activity as a TUTT-low amplifies near the
Lesser Antilles, weakening the mid to upper-level high-pressure
ridge across the Northeastern Caribbean, promoting showery weather
due to the enhanced low-level convergence. A limited risk of
excessive rainfall is expected each day of the short-term period.

.LONG TERM...Saturday trough Wednesday...

A broad surface high-pressure system over the central Atlantic
will maintain a moderate easterly trade wind flow across the
region on Saturday. Meanwhile, a strong upper-level trough
developing just east of the islands will weaken the mid to upper-
level ridge, reducing stability in the atmosphere. This strong
upper-level future will reflect at the surface and cloudiness and
moisture across the Atlantic will reach the local islands dragged
by the easterly winds during the period.

On Sunday, as the surface high-pressure system shifts eastward,
the pressure gradient will become stronger, causing an increase in
wind speeds across the region. This change will accelerate the
easterly trade winds, bringing moisture inland and enhancing local
effects, resulting in shower activity across the interior and
eastern slopes sections of Puerto Rico. PWAT values will rise to
approximately 1.5 inches. Combined to that moisture, global model
guidance suggest an cold trend at the 500 MB temperatures by
Friday into Saturday, providing space for the development of
isolated thunderstorms. Expect stronger trade wind showers, some
of which could bring brief heavy rain and gusty winds, especially
in the overnight and early morning hours. From Monday through
Wednesday, the easterly trade winds will continue to bring patches
of moist air into the region, leading to partly cloudy skies and
scattered showers. These showers will mainly affect coastal and
windward areas during the night and early morning hours. By the
afternoon, some localized convection could develop over western
and interior Puerto Rico, mainly due to daytime heating and sea
breeze interactions. However, as the mid- level ridge builds back
in, it will help limit thunderstorm activity by creating a more
stable atmosphere. Even so, brief heavy downpours, ponding of
water on roads, and occasional gusty winds remain possible with
the strongest showers.

&&

.AVIATION...

(06Z TAF) VFR conditions will prevail across all TAF sites. However,
showers may cause brief MVFR conditions at TJBQ and
TJPS after 29/16Z with expected VCSH. E winds at 5-12 kt after
29/13Z, with occasionally higher gusts near the heaviest rainfall
activity.

&&

.MARINE...

A surface high-pressure system over the central Atlantic will
continue to support moderate to locally fresh easterly winds,
leading to choppy, wind-driven seas across most local waters and
passages, where small craft should exercise caution. By the latter
part of the week, another strong high-pressure system will
strengthen over the western Atlantic, increasing fresh to locally
strong trade winds and deteriorating marine conditions, especially
across the Atlantic waters and passages, where small craft
advisories may be needed. On Friday, a pulse of energy from a
northerly swell and the wind driven seas will result in confused
seas, leading to hazardous marine conditions.


&&

.BEACH FORECAST...

There is a moderate risk of rip current for most of the locally
exposed beaches on the islands today through Thursday. A strong
high-pressure system will strengthen over the western Atlantic,
increasing trade winds and rougher surf, particularly along east
and north-facing beaches of Puerto Rico and the U.S. Virgin
Islands. By Friday, a pulse of northerly swell energy will lead to
higher breaking waves along northern beaches, increasing the risk
of dangerous rip currents and hazardous surf conditions.
Beachgoers should exercise caution, as strong currents and rough
surf could make swimming and coastal activities dangerous.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
504 AM AST Thu Jan 30 2025

.SYNOPSIS...

Today, expect isolated to scattered showers moving across the
windward sectors of the islands and this afternoon particularly
across the southwestern quadrant of Puerto Rico. A weak Saharan
Air Layer will gradually fill in tonight and last through
Thursday. Breezy conditions will prevail through the weekend,
with passing showers moving from time to time during the night and
early morning hours under an advective weather pattern.

&&

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

A variable weather pattern will persist across Puerto Rico and the
U.S. Virgin Islands, with frequent isolated to moderate showers
affecting the northeastern sections of Puerto Rico. Although shower
activity has been persistent, rainfall accumulations will remain
insignificant. The local pressure gradient remains weak, with the
pre-frontal trough located north of the area, allowing winds to be
light and variable. Surface temperatures will remain in the mid-to-
upper 70s across coastal areas, while orographic cooling will lead
to temperatures in the lower-to-mid 60s across the mountainous
interior.

For today, a broad surface high-pressure system will build over the
western Atlantic as the pre-frontal trough continues moving eastward
into the central Atlantic. As this high-pressure ridge extends
further into the Atlantic basin, the local wind flow will shift to
an east-northeast direction, enhancing low-level moisture advection.
GOES satellite-derived total precipitable water (TPW) imagery
indicates a sufficient moisture plume lingering into the early
afternoon, supporting the development of isolated to scattered
shower activity, particularly across the southwestern quadrant of
Puerto Rico due to localized orographic lifting and diurnal heating
effects.

By Friday, global weather models indicate an increase in relative
humidity values trapped within the 850-500 MB layer, associated with
a slight colder temperatures at 500 MB rounding between -5 to -6 C.
Given the expected conditions, Thursday night into early Friday
morning is anticipated to be the wettest period within the short-
term forecast, with enhanced shower activity, particularly across
windward sections of the U.S. Virgin Islands. Nearly the same
period, a slightly area of drier air with some Saharan Dust particles
with reach the islands, resulting in some haziness. By Saturday, a
broad surface high-pressure system anchored over the central
Atlantic will induce a tightening of the local pressure gradient,
resulting in breezy conditions across the region. This enhanced
trade wind flow may also contribute to fast-moving low-level cloud
patches embedded within the prevailing flow, leading to brief,
passing showers across windward coastal areas.

&&

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

For the long term, a series of surface high-pressure systems will
continue to induce breezy to windy east to northeast trade winds,
On Sunday, that pattern will bring moisture across the region and
enhance local effects. This will result in shower activity,
especially across the interior and eastern half of Puerto Rico.
Latest model guidance suggests that precipitable water values will
rise to 1.5 inches or greater that day, which is considered
above-normal for this time of year.

From Monday through Wednesday, the mid-level ridge will build back and
bring some stability to the area, but trade wind perturbations
will move through each day, bringing periods of showery weather.
Expect a mix of moist and dry air patches moving across the
region, leading to partly cloudy skies and scattered showers.
These showers will mainly affect coastal and windward areas during
the night and early morning hours. In the afternoons, localized
convection may form over western and interior Puerto Rico,
primarily due to daytime heating and sea breeze interactions.
Ponding of water on roads and in poorly drained areas is likely,
and residents and visitors are encouraged to exercise caution on
roadways.

Temperature-wise, the 925 mb temperatures are forecast to drop a
few degrees, remaining within seasonal values, resulting in
slightly cooler temperatures through mid week. For more details,
visit the Experimental Graphical Hazard Weather Outlook at
https://www.weather.gov/erh/ghwo?wfo=sju.

&&

.AVIATION...
(06Z TAFs)

VFR conditions will persist for all the TAF sites during
the period. VCSH and -RA will persist across TJSJ at least until
30/15Z. Winds will increase from the E-NE, increasing to 15 knots
with gusty winds. VCSH is expected for TJPS in the afternoon.

&&

.MARINE...

A surface high pressure across the eastern Atlantic and a pre-frontal
trough from a frontal boundary well at north of the region will
result in gentle to locally moderate easterly winds across the local
waters today. Another strong high pressure will gradually build
across the eastern Atlantic, leading to moderate to locally fresh
winds tonight, and fresh to locally strong winds from Friday onward.
These increasing winds, along with a small northerly swell, will
likely deteriorate marine conditions for small craft in most water
zones from Friday through at least early next week.

&&

.BEACH FORECAST...

There is low to moderate risk of rip currents today and tonight across
the northern and eastern beaches of PR, Culebra, and St. Croix. A
moderate risk will likely persist over the next few days. A small
northwesterly swell and choppy wind-driven waves will increase
the risk of rip currents later during the weekend.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Fri Jan 31 2025

.SYNOPSIS...

Isolated to scattered showers will likely continue this morning
resulting in variable weather conditions today, followed by a
drier airmass tonight. A weak Saharan Air Layer will continue
fill and linger through the weekend. Breezy conditions will
prevail through the weekend, with passing showers moving from time
to time during the night and early morning hours under an
advective weather pattern.

&&

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

A variable weather pattern persisted through the night, with
isolated to moderate showers affecting the eastern sections of
Puerto Rico and the U.S. Virgin Islands. After 2 AM, shower activity
shifted toward the northern portions of Puerto Rico, impacting areas
from the San Juan metro to Aguadilla. Notably, intense rainfall was
observed over Barceloneta and some sections of the San Juan Metro
area, where Doppler radar estimates indicated nearly half an inch of
accumulation. Overnight temperatures ranged from the low to mid-60s
across the mountainous regions and the low to mid-70s along the
coastal areas.

The variable weather pattern will continue through the morning and
early afternoon as a weak induced surface trough continues the path
across the region. This disturbance will bring increased cloudiness
and moisture, resulting in a wet morning across most of the islands
and a variable afternoon. However, rainfall accumulations are
expected to remain low, with only a limited ponding of water on
roadways. Winds will remain strong to vigorous from the east-
northeast due to the influence of a strengthening high-pressure
system over the western Atlantic and its interaction with a nearby
frontal boundary.

For Saturday into Sunday, model guidance suggests some instability
across the region as a strong upper-level trough, located just east
of the area, erodes in someway the mid-to-upper-level ridge. This
will result in colder temperatures at the 500 MB level. However,
despite this instability, limited surface moisture and the arrival
of a dry air mass with Saharan dust particles will contribute to
mostly stable weather conditions. Any showers that develop will be
driven by local and diurnal effects. As a result, hazy skies will be
present by Saturday with no-significant flooding threat expected.

&&

.LONG TERM...Sunday through Friday...

The long-term forecast will be characterized by variable weather
conditions. According to the latest model guidance, a mid-level
ridge is expected to build over Cuba and the Bahamas at the start
of the week, bringing stability to the middle and upper levels of
the atmosphere. Precipitable water values are likely to fluctuate
between below-normal and seasonal levels, ranging from 1.00 to
1.5 inches. A mix of moisture and dry air pockets will move within
the trades daily, resulting in typical conditions where showers
develop, mainly affecting coastal and windward areas during the
night and early morning hours. In the afternoons, localized
convection may form over western Puerto Rico, primarily due to
daytime heating and sea breeze interactions.

Winds will continue with an east-northeast component throughout
the week, driven by high pressure over the Atlantic. This will
keep conditions breezy, especially along coastal areas of the
islands. For this reason, any showers that develop are expected to
move quickly, and while there are no flooding concerns at the
moment, ponding of water on roads and in poorly drained areas is
likely. Residents and visitors are encouraged to exercise caution
on roadways.

By mid to late week, a stronger high pressure system will
establish itself over the western Atlantic, tightening the
pressure gradient even further across the region, which will keep
winds breezier. Daytime temperatures are expected to range from
the mid to upper 80s in lower elevations and mid to upper 70s in
higher elevations, with overnight lows in the 70s and 60s,
respectively.

&&

.AVIATION...
(06z TAFs)

VFR conditions will persist for all the TAF sites during the
period. VCSH and -RA will persist across most of the TAF sites at
least until 31/19Z. Winds will increase from the E-NE, increasing
to 15 knots with gusty winds. After 31/23Z winds will slightly
diminish becoming from the E at 10 knots.

&&

.MARINE...

A weak induced surface trough will continue to move across the
region this morning resulting in isolated to scattered showers
across the local waters. A building surface high pressure over the
western Atlantic will promote moderate to locally strong east to
northeast winds from today onward. These increasing winds, along
with a small northerly swell, will promote choppy to hazardous seas
across most of the local waters through at least early next week.

&&

.BEACH FORECAST...

There is a moderate risk of rip currents along all the coastal
areas of Puerto Rico, including Vieques and Culebra, and along
the U.S. Virgin islands. This means that life-threatening rip
currents are possible in the surf zone and beachgoers should
exercise caution. A small northwesterly swell and choppy wind-
driven waves will increase the risk of rip currents later during
the weekend.

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST Sat Feb 1 2025

.SYNOPSIS...

Variable weather conditions will prevail for today into the rest
of the weekend. Patches of cloudiness and moisture will continue
to streak along northeastern sections of the islands and local
waters with no flooding impact for the day. By late today into
early tomorrow, some Saharan Dust particles would arrive, but
quite after that cloudiness and showers will affect eastern
sections of Puerto Rico and the U.S. Virgin Islands. Hazardous
marine conditions will prevail due to wind-driven seas for today
into the upcoming workweek. Therefore, several small craft
advisories remains in effect.

&&

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

Overnight, weather conditions remained generally calm, with mostly
clear skies across the western half of Puerto Rico. Meanwhile, the
eastern half of Puerto Rico and the U.S. Virgin Islands experienced
some clouds and brief showers. Since midnight, radar estimates
indicated rainfall totals of around 0.20 inches over the eastern
sectors of Puerto Rico. Surface observations showed low temperatures
in the mid to upper 70s along coastal and urban areas, while higher
elevations and rural areas saw temperatures in the 60s. Winds were
predominantly from the east at around 10 mph or less over land.

Latest precipitable water (PWAT) guidance indicates values ranging
from below normal to seasonal levels today, leading to variable
weather conditions. Additionally, a mid-to-upper-level trough will
deepen to the east of our region, near the Leeward Islands, causing
some ventilation and instability aloft. This will result in colder
temperatures at mid levels and lower 250 MB heights over the weekend
into early next week. Showers are expected this morning over the
eastern sectors of Puerto Rico and the U.S. Virgin Islands, followed
by the development of isolated to scattered showers across the
interior and western areas during the day and afternoon. Winds will
remain breezy from the east-northeast with gusty periods, driven by
a strong surface high-pressure over the Central Atlantic. This will
help move developing showers quickly, with only limited ponding of
water on roadways and in poorly drained areas.

A similar pattern is expected to continue through the end of the
forecast period. By Sunday into Monday, models suggest PWAT values
will slightly increase and remain at seasonal levels, ranging from
1.3 to 1.6 inches. This will be due to the arrival of patches of
moisture embedded in the easterly to northeasterly trades, resulting
in the continuation of showers, mainly affecting coastal and
windward areas during the night and morning hours. In the
afternoons, localized convection may form over the interior and
western Puerto Rico, primarily due to daytime heating and sea breeze
interactions. Note that low concentrations of Saharan dust
particulates will also be present during the short term period,
bringing slightly hazy skies to areas with limited shower activity.
Daytime temperatures are expected to range from the mid to upper 80s
in lower elevations and in the mid 70s to low 80s in higher
elevations, with overnight lows in the 70s and 60s, respectively.

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

A surface high-pressure system over the Western Atlantic will
extend into the Caribbean on Tuesday, inducing moderate to fresh
east-northeast winds across the region. A mid-level ridge will
maintain dry and stable conditions aloft, limiting significant
rainfall development. As a result, Puerto Rico and the U.S. Virgin
Islands can expect mainly fair weather, with brief, light showers
affecting eastern coastal areas during the early morning hours.

By Wednesday into Thursday, as the surface high-pressure system migrates
toward the central Atlantic, patches of trapped moisture will
continue to reach the islands. The tightening pressure gradient
will enhance trade winds, resulting in breezy to windy conditions.
Scattered showers will affect the U.S. Virgin Islands and eastern
Puerto Rico during the morning, bringing the potential for
ponding of water on roadways and poor drainage areas. During the
afternoons, localized convection resulted from the daytime heating
and local effects could lead to isolated showers over western and
interior Puerto Rico. These showers may bring brief heavy
rainfall, potentially causing minor urban and small-stream
flooding, particularly in low-lying areas. On Friday, the overall
pattern will persist, with the islands remaining under the
influence of the high-pressure system, but winds will turn more
from the east. Morning showers will continue to affect eastern
Puerto Rico and the U.S. Virgin Islands, potentially impacting
eastern sections in the early morning hours. Again, afternoon
convection over western Puerto Rico could result in water ponding
if so. No significant changes are expected on Saturday, as the
islands remain under the dominance of the Atlantic high pressure.
Therefore, significant rainfall is not anticipated.

Overall, while no significant weather systems are forecast, the combination
of moderate to strong trade winds and intermittent moisture
surges will keep Puerto Rico and the U.S. Virgin Islands under
variable weather conditions. Residents should remain cautious of
occasional heavy showers and ponding on roadways, particularly
later in the week.

&&

.AVIATION...
(06Z) Mainly VFR conditions will prevail during the next 24
hours. However, SHRA/VCSH embedded in the NE trades could result
in brief MVFR conditions across TAF sites during the day. ENE
winds at 12-18 kts with higher gusts at 20-25 kts after 01/14Z,
decreasing to around 10 knots after 22Z to 23Z.

&&

.MARINE...

A building surface high pressure over the Western Atlantic
extending into the Central Atlantic will continue to support a
moderate to locally fresh easterly wind pattern across the region,
resulting in wind-driven seas. Given the current conditions,
recent data from the local buoy network indicates seas ranging
from 5 to 7 feet, creating hazardous marine conditions,
particularly for small craft operators. As a result, several small
craft advisories remain in effect until Sunday, especially across
the offshore waters and local passages, with the potential for
hazardous conditions extending into the upcoming workweek.
Mariners are urged to exercise caution in the coming days.

&&

.BEACH FORECAST...

Wind-driven seas will continue contributing to choppy marine
conditions across local coastal waters. While the current rip risk
will remain moderate across most exposed beaches, some north coast
beaches and other coastal areas that are not considered safe for
beachgoers could pose a more significant hazard for residents and
visitors. Similar conditions are expected to persist through
Sunday and into the upcoming workweek.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
447 AM AST Sun Feb 2 2025

.SYNOPSIS...

Variable weather will persist through the rest of the weekend into
the upcoming workweek, with patches of clouds and moisture moving
across the region, though no flooding is expected. Hazardous
marine conditions will continue due to wind-driven seas, with
small craft advisories remaining in effect into the workweek.

&&

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

Overnight, skies were generally clear to partly cloudy over land
areas, with light to moderate rainfall affecting northern and
eastern Puerto Rico and the U.S. Virgin Islands. Radar estimates
indicated rainfall totals between 0.20 and 0.40 inches in these
areas since midnight. Surface observations recorded low
temperatures in the mid to upper 70s along coastal and urban
regions, while higher elevations and rural areas saw cooler
temperatures in the 60s. Winds were predominantly from the east
northeast at around 10 to 12 mph, with higher gusts near coastal
areas.

The short-term forecast will be characterized by variable weather
conditions. At the surface, a high pressure system across the
eastern Atlantic will provide easterly to northeasterly breezy
winds. Aloft, a mid-to-upper-level trough located over the Leeward
Islands will continue to move eastward today, while a mid-to-upper-
level ridge centered over Cuba will mainly dominate the weather
pattern in the coming days. The latest precipitable water (PWAT)
guidance indicates values mainly near seasonal levels throughout the
forecast period, except today, when a patch of moisture will
continue to move in, and values could reach up to 1.65 inches, which
is considered above normal. This will promote the continuity of
showery and variable weather, and out of the next three days, today
and tonight should have the best rain chances and coverage. As a
result, occasional showers are expected this morning over the
windward sectors of Puerto Rico and the U.S. Virgin Islands,
followed by the development of scattered showers across the interior
and western areas during the afternoon. Tonight, northern coastal
areas and eastern Puerto Rico and the U.S. Virgin Islands will
experience showery weather once again. On Monday and Tuesday, a
similar weather pattern will persist but with reduced shower
coverage as a mixture of drier and moist air moves through the trade
winds. While flooding is not a concern, limited ponding on roads and
in poorly drained areas is likely, so drivers should exercise
caution. Traces of Saharan dust will also be present during this
period, causing slightly hazy skies in areas with fewer showers.

Daytime temperatures will range from the mid to upper 80s in lower
elevations, and from the mid-70s to low 80s in higher elevations,
with overnight lows in the 70s and 60s.

.LONG TERM..Wednesday trough Sunday...

The long term forecast remain on track. A mid-level ridge will
maintain dry and stable conditions aloft, limiting significant
rainfall development. As a result, Puerto Rico and the U.S. Virgin
Islands can expect mainly fair weather, with brief, light showers
affecting eastern coastal areas during the early morning hours.
By Wednesday into Thursday, the surface high-pressure system
over the western Atlantic in interaction with a pre-frontal trough
well north of the region will induce a east-northeast wind flow
across the islands. Embedded in the winds patches of trapped
moisture with PWAT of 1.2 to 1.5 inches will reach the islands.
The tightening pressure gradient will enhance trade winds,
resulting in breezy to windy conditions. Scattered showers will
affect the U.S. Virgin Islands and eastern Puerto Rico during the
morning, bringing the potential for ponding of water on roadways
and poor drainage areas. During the afternoons, localized
convection resulted from the daytime heating and local effects
could lead to isolated showers over western and interior Puerto
Rico. These showers may bring brief heavy rainfall, potentially
causing minor urban and small-stream flooding, particularly in
low-lying areas.

From late Friday into the weekend, conditions will become wetter
as continued patches of trapped moisture move across the region,
as a building surface high pressure migrates from the Western
Atlantic into the eastern Atlantic. This will mark the wettest
period of the long- term forecast. Additionally, an open and weak
mid- to- upper level trough will be present, resulting in
increased instability aloft. This feature will enhance ventilation
and introduce colder temperatures at 500 MB, supporting some
convective development. As a result, scattered to numerous showers
are expected, particularly across eastern Puerto Rico and the
U.S. Virgin Islands in the mornings, with afternoon convection
developing over western and interior Puerto Rico. These showers
may produce periods of moderate to heavy rainfall, increasing the
potential for ponding of water on roadways and minor urban
flooding. Additionally, with the local and diurnal heating, some
isolated thunderstorms cannot be ruled out with the heaviest
shower activity.

&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions will prevail during the next 24 hours.
However, variable and showery weather will continue with the ENE
trades. This will result in SHRA and VCSH throughout the day,
primarily affecting northern Puerto Rico TAF sites and the U.S.
Virgin Islands. Brief MVFR conditions may occur at these sites as a
result. ENE winds will range from 12 to 18 knots, with gusts between
20 to 25 knots after 02/14Z. Winds will decrease to around 12 knots
between 22Z and 23Z.

&&

.MARINE...

A surface high-pressure system over the Central Atlantic will
maintain a moderate to locally fresh easterly wind flow,
contributing to wind-driven seas across the region. Seas will
fluctuate between 5 and 7 feet, creating hazardous conditions,
particularly for small craft. Consequently, multiple small craft
advisories remain in effect through Monday, especially for
offshore waters and local passages, with the possibility of rough
conditions persisting into the early workweek. Mariners should
remain vigilant and exercise caution as these conditions continue.

&&

.BEACH FORECAST...

Hazardous coastal conditions will persist as wind-driven seas
maintain choppy waters for today into the upcoming workweek. While
most exposed beaches will experience a moderate risk of rip
currents, specific north-facing beaches, and other less sheltered
coastal areas may present a higher danger to swimmers and
beachgoers.

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
529 AM AST Mon Feb 3 2025

.SYNOPSIS...

Variable weather under breezy E-NE winds will persist during the
next few days, with a mixture of sunshine and patches of clouds
and passing showers moving across the region, though no
significant flooding is expected. In general, similar conditions
are expected through the workweek, with greater chances of
afternoon rains by mid week. Hazardous marine conditions will
continue due to wind- driven seas, with small craft advisories
remaining in effect today into tomorrow.

&&

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

The weather pattern has remained consistent, with radar and satellite
imagery showing fast-moving trade wind showers affecting Puerto
Rico’s northern and eastern halves, Vieques, Culebra, and the U.S.
Virgin Islands, driven by breezy east-northeasterly trade winds.
Radar-estimated rainfall has indicated up to half an inch over
northeastern Puerto Rico since midnight, though surface stations
have reported less than a quarter of an inch. Overnight
temperatures have been typical, ranging from the lower 60s in
higher elevations to the mid to upper 70s across lower elevations
and the local islands.

A surface high pressure over the western Atlantic and an old
frontal boundary to the north will maintain an east-northeasterly
wind flow. At mid-levels, a ridge will persist through Tuesday,
limiting significant shower development. However, the ridge will
be displaced by a mid-level trough by Wednesday, bringing slightly
more favorable conditions for showers. In response, moisture
levels will fluctuate, with precipitable water values generally
oscillating around typical levels (1.2-1.5 inches), and slightly
higher into above normal levels on Wednesday. While model
guidance suggests a gradual decrease in wind speeds through
midweek, breezy conditions will persist, especially along coastal
areas and the local islands during peak sea breeze hours.
Temperatures will remain near normal, with overnight lows in the
lower 60s and daytime highs in the mid-80s.

Overall, expect a weather pattern dominated by occasional to frequent
fast-moving showers, with the highest impact across the U.S.
Virgin Islands and northeastern Puerto Rico. Localized afternoon
convection is possible over the interior and western to
southwestern Puerto Rico. However, with ridging in place through
Tuesday, significant rainfall is unlikely. By Wednesday, the mid-
level trough will enhance instability and increase moisture
levels, raising the potential for more shower development.

Currently, the most significant hazard risks are from winds and wind-
related threats through midweek, despite periods of frequent
showers that may give the impression of excessive rainfall risks.
For more details on this and other hazards, visit the Experimental
Graphical Hazard Weather Outlook at
https://www.weather.gov/erh/ghwo?wfo=sju.


.LONG TERM...Thursday to Monday...

No major changes to the long term forecast. East-northeast steering
flow will bring patches of moisture towards the islands to start the
long term period. Precipitable water (PWAT) values will reach around
1.5 inches with the strongest patches. This steering flow will be
due to the interaction between a surface high pressure over the
western Atlantic and a pre-frontal trough well north of the region.
The tightening pressure gradient will promote breezy to windy
conditions which will steer isolated to scattered showers over
windward sectors during the morning hours. During the afternoon
hours, sea breeze convergence, diurnal heating and local effects
will promote localized convection mainly over interior to western
Puerto Rico, which can promote a limited flooding risk. More
frequent moisture patches will arrive late Friday and into the
weekend as the surface high pressure moves towards the eastern
Atlantic and a weak mid to upper level trough increases instability
aloft, enhances ventilation and reduces temperatures at 500 mb. This
will help boost the local rain pattern, particularly afternoon
convection over western Puerto Rico. Highs can reach the low to mid
80s (locally higher especially in W-SW-S PR) across lower elevations
of the islands. Lows can reach the upper 50s to 60s across higher
elevations of Puerto Rico, and from the low to mid 70s across lower
elevation of the islands. Patchy fog can also be present during the
overnight to early morning hours across sectors of interior Puerto
Rico.

&&

.AVIATION...

(06Z TAFS)

Variable and showery weather driven by breezy ENE trade winds will
persist, with SHRA to VCSH mainly affecting northern PR TAF sites
and the USVI, leading to brief MVFR periods. VCSH may also impact
TJPS between 03/17-22Z. Winds will increase from 5-10 knots to
15-18 knots, gusting 20-30 knots, after 03/14Z, then decrease to
8-10 knots by 03/22Z.

&&

.MARINE...

A surface high pressure over the western Atlantic migrating eastward,
will maintain moderate to fresh east-northeast winds through at least
today. Winds should subside somewhat tomorrow, Tuesday, but another
pulse of breezy conditions is anticipated for the middle and latter
part of the workweek. These winds will maintain choppy and hazardous
seas for small craft operators, especially along the offshore waters
and local passages. Small Craft Advisories are in effect for the
Offshore Atlantic waters through noon tomorrow, and for the
offshore Caribbean waters, and local passages through noon today.
Small Craft should Exercise Caution over the nearshore
northwestern, northern and eastern waters of Puerto Rico, as well
as the waters surrounding St. Thomas and St. John.

&&

.BEACH FORECAST...

Hazardous coastal conditions will persist as wind-driven seas
maintain choppy waters today. While most exposed beaches will
experience a moderate risk of rip currents, specific north-facing
beaches, and other less sheltered coastal areas may present a
higher danger to swimmers and beachgoers. Up to a moderate rip
current risk is forecast through the workweek.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
455 AM AST Tue Feb 4 2025

.KEY MESSAGES...

* Breezy conditions will persist, impacting outdoor activities and
operations. Stay prepared and adjust plans accordingly.

* Low humidity, breezy winds, and drying soils will create favorable
conditions for fire spread today. Take precautions to minimize
fire risks.

* Small craft operators should take action to avoid hazardous seas
caused by breezy conditions, which will continue through the
weekend.

* Life-threatening rip currents are possible, especially along
northern and southeastern Puerto Rico, Culebra, Vieques, and the
U.S. Virgin Islands. Beachgoers must stay alert and avoid
dangerous waters.

* Variable weather will persist during the next several days with
passing showers moving from time to time over windward areas.
Localized afternoon convection is possible over interior to
W-SW PR.

&&

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

The weather pattern has remained consistent, with radar and
satellite imagery showing fast-moving trade wind showers affecting
northern and eastern into the eastern interior and central interior
sections of Puerto Rico, Vieques, Culebra, and the U.S. Virgin
Islands, driven by breezy east-northeasterly trade winds. Radar-
estimated rainfall has indicated up to a quarter of an inch over
localized areas of northeastern Puerto Rico since midnight, far from
surface stations, which have reported less than a tenth of an inch
over the same period. Overnight temperatures have been typical,
ranging from the lower 60s in higher elevations to the mid to upper
70s across northeastern Puerto Rico and the local islands.

A surface high over the Bermuda region will maintain breezy east-
northeasterly winds today while a mid-level ridge suppresses
significant shower development. As the surface high weakens, wind
speeds may briefly decrease on Wednesday, but breezy conditions will
persist. By Thursday, a new surface high moving off the U.S. west
coast will strengthen winds, increasing hazards along coastal areas
and local islands, especially during peak sea breeze hours.
Meanwhile, the mid-level ridge will give way to a trough on
Wednesday, increasing instability and moisture. Precipitable water
values will rise from 1.1-1.5 inches today to around 1.6 inches
Wednesday into Wednesday night before returning to typical levels on
Thursday.

The weather pattern will feature occasional fast-moving showers,
with increased activity during peak moisture periods. The most
significant impacts are expected across the U.S. Virgin Islands and
northeastern Puerto Rico. Localized afternoon convection may develop
over the interior and western to southwestern Puerto Rico, with the
trough potentially enhancing rainfall accumulations on Wednesday.
Temperatures will remain near normal, with lows in the lower 60s and
highs in the mid-80s.

The most significant hazard risks are from winds and wind-related
threats, with periods of increased showers enhancing excessive
rainfall risks on Wednesday. Dry conditions and breezy winds, along
with drying soils and available fuels, will also support a fire
danger risk today. For more details on this and other hazards, visit
the Experimental Graphical Hazard Weather Outlook at
https://www.weather.gov/erh/ghwo?wfo=sju.

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

The long term forecast remains on track. East to east-northeasterly
winds will continue to prevail across the region during the period,
with breezy conditions through at least early next week. The breezy
conditions will be caused by a strong high pressure that will
establish to the north-north east of the area, causing a tight
pressure gradient. These winds will keep an advective pattern with
occasional patches of moisture crossing our region, bringing periods
of more frequent showers across the windward areas (N & E sections
and the local islands). The weekend, particularly Saturday, looks to
be the wettest period due to more frequent moisture patches reaching
the area and slightly greater instability aloft due to a weak mid to
upper level trough crossing the area. This will enhance the
ventilation, reduce temperatures at 500mb and allow the moisture
layer to extend from the surface up to just under 500mb, with
Precipitable Water (PWAT) values around 1.6 inches, which is
slightly above normal for this time of the year. This will help
boost the local rain pattern, particularly afternoon convection over
western Puerto Rico. However, no significant flooding threat is
expected due to the breezy conditions.

Relatively drier conditions will follow early next week, but still
breezy and variable with the occasional patches of moisture reaching
the area. PWAT values will remain at seasonal levels, with slightly
below normal values possible for Tuesday. In general, continue to
expect an advective pattern across the windward sections with a
mixture of sunshine and rain during the entire period, with gusty
conditions.

Temperatures will not change much during the period with highs
ranging from the low to mid 80s across lower elevations of the
islands (locally higher especially in W-SW-S PR). Lows can reach the
upper 50s to 60s across higher elevations of Puerto Rico, and from
the low to mid 70s across lower elevation of the islands. Patchy fog
can also be present during the overnight to early morning hours
across sectors of interior Puerto Rico.

&&

.AVIATION...

(06Z TAFs)

Variable and showery weather driven by breezy ENE trade winds will
persist, with SHRA to VCSH mainly affecting northern PR and the USVI
TAF sites, leading to brief MVFR periods. VCSH may also impact TJPS
between 04/16-22Z. Winds will increase from 5-10 knots to 15-18
knots, gusting 20-30 knots, after 04/14Z, then decrease to 8-10
knots by 04/22Z.

&&

.MARINE...

A surface high pressure over the western Atlantic migrating eastward,
will maintain moderate to fresh east-northeast winds through today,
with winds subsiding somewhat tonight and tomorrow. However, as
another surface high pressure builds north of the region from
Thursday onwards, breezy conditions will return. These winds will
maintain choppy to hazardous conditions for small crafts across the
offshore Atlantic, while choppy seas will persist elsewhere.

&&

.BEACH FORECAST...

Hazardous coastal conditions will persist as wind-driven seas
maintain choppy waters today. While most exposed beaches will
experience a moderate risk of rip currents, specific north-facing
beaches, and other less sheltered coastal areas may present a
higher danger to swimmers and beachgoers. Up to a moderate rip
current risk is forecast through the workweek. It is possible that
the risk of rip current increases to high during the weekend. For
more information please refer to the latest Surf Zone Forecast
(SRFSJU).

&&

.FIRE WEATHER...

Favorable conditions for fire spreading are possible today,
particularly across the southern coastal plains, southern hills, and
western Puerto Rico, due to drying soils, available dry fuels, below-
normal moisture, and breezy to gusty conditions. Recent fire
activity and firefighter mobilization, observed via satellite and
social media, highlight the ongoing threat. While some afternoon
showers may develop over the southern hills and far southwestern
Puerto Rico, they will not provide significant wetting rains. Skies
will be mostly clear to partly cloudy, with highs in the mid-upper
80s and minimum relative humidity dropping to the mid-40s. Peak wind
speeds will range around 15-20 mph, with gusts around 25-30 mph.
KBDI readings have reached 557 in southern Puerto Rico, signaling
increased dryness. These conditions will support the rapid spread of
new fires, particularly in fire-prone areas.

&&

.CLIMATE...

During the month of January and the first couple days of February,
several Warmest Low Temperature records were tied or broken in
our climate sites. At the San Juan Area Station (at Luis Munoz
Marin Airport), 13 daily warmest low temperature records were
either tied or broken. At the Cyril E. King Airport in St.
Thomas, 3 daily warmest low temperature records were either tied
or broken. At the Henry E. Rohlsen Airport in St. Croix, 3 daily
warmest low temperature records were either tied or broken. For
more information, please refer to the latest Record Event Reports
for each station, RERSJU (spanish translation at RERSPN), RERIST
and RERISX.