Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
423 AM AST Wed Jan 11 2023

.SYNOPSIS...
Sunny to partly cloudy skies will prevail in the morning, with
deteriorating weather conditions across the central sections in
the afternoon. Instability aloft will enhance the development of
some isolated thunderstorms. For the upcoming weekend, another
frontal boundary will move across the local islands, increasing
the showers for the local islands.

&&

.SHORT TERM...TODAY THROUGH FRIDAY...

Once again, expect a mixture of clouds and sunshine in Puerto Rico
and the U.S. Virgin Islands through the morning hours. The winds
today will be out from the east-southeast, but due to the proximity
of a shear line and an induced pre-frontal trough, winds will
continue to be weak and influenced by the local sea breeze
variations. Therefore, afternoon convection will be driven mainly by
sea breeze variations, diurnal heating, and orographic effects. As
it forms and due to the lack of steering winds, they will spread
across the rest of mainland Puerto Rico, increasing the risk of
observing urban and small stream flooding. In addition, the Gálvez-
Davison Index (GDI) indicated atypical high values, especially
during the afternoon, which may result in numerous showers and
isolated thunderstorms.

Winds will veer from east-southeast to east by Thursday as the shear
line dissipates north of the islands and from the east to east-
northeast by Friday. However, above-normal moisture and low-level
instability will continue to result in isolated/scattered showers
across the islands during the night and morning. GDI values also
suggest the formation of scattered to numerous showers during the
afternoons, with a slight risk of isolated thunderstorms. Although
we anticipate periods of sunshine and clear skies each day,
scattered to numerous showers will affect portions of the islands
and local waters, with somewhat more vigorous afternoon convection
across the interior and western sections.

&&

.LONG TERM... Saturday through Thursday.

A mid to upper level trough and the associated frontal boundary
will provide unsettled weather conditions during the first part of
the long-term period. These unstable conditions aloft will combine
with low level moisture at the surface, enhancing the potential
for shower activity across the local islands. Given the change in
the wind direction from the north, as the frontal moves eastward
into the Central Atlantic, shower activity will be focused on the
north and central sections of Puerto Rico. Colder temperatures at
500 MB can enhance the potential for some isolated thunderstorms
with the heaviest activity. There is a potential for urban and
small stream flooding, especially across the San Juan Metro area
and north central sections.

On Monday, weather conditions will improve across the forecast area
as a high building pressure over the western Atlantic moves
eastward to the Central Atlantic, pushing the frontal boundary.
Embedded in the northerly winds, drier air with precipitable water
below normal will reach the local area, limiting the potential
for a widespread shower activity. This pattern will persist until
Tuesday with fair weather conditions and colder temperatures
across the islands. Trade wind pattern is again forecast on
Wednesday as the broad surface high pressure move at the central
Atlantic. On Thursday, trade winds showers from the remnants of
the frontal boundary moisture will filter into the regions,
increasing the frequency of the passing showers.

&&

.AVIATION...

VFR conditions will continue through the forecast period, with the
arrival of occasional SHRA/+SHRA over JSJ/IST/ISX. +SHRA/isolated -
TSRA will develop across the interior, spreading toward the
northwest and downwind from El Yunque/the USVI between 11/16-23z,
producing mountain obscuration, and may impact the local terminals,
including JBQ. Winds will continue calm-light/VRB thru 11/13z and
out of the ESE at 8-13 kt with sea breeze variations after 11/13z.

&&

.MARINE...

Across the regional waters, seas will remain up to 5 feet across
the Atlantic offshore waters and up to 4 feet across the rest of
the nearshore waters. Winds will remain light to moderate from the
east across most local waters. There is a low risk of rip
currents across all the exposed beaches, increasing to moderate on
Thursday.

For the upcoming weekend, hazardous marine conditions are
forecast with the arrival of a northerly swell across the offshore
Atlantic waters.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM...CAM
LONG TERM....LIS
AVIATION...CAM

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
443 AM AST Thu Jan 12 2023

.SYNOPSIS...

A mixture of sunshine and clouds is expected throughout the
morning hours. A shear line off to the north of the islands will
continue to promote above-average moisture and a weak wind flow
that, combined with sea breeze variations and local effects, will
result in scattered to widespread activity. Observing flooding of
urban areas and small streams is possible, and isolated flash
floods cannot be ruled out. A cold front approaching from the
northwest of Puerto Rico could promote unsettled weather
conditions by Sunday. Conditions may improve late Monday through
at least Wednesday next week, returning the pleasant tropical
winter temperatures.

&&

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

The remnants of a frontal boundary north of the islands will
continue to promote above-normal moisture pooling over the
Northeast Caribbean. Afternoon convection will be driven mainly
by sea breeze variations, diurnal heating and orographic effects.
These factors will promote favorable conditions for widespread
showers and isolated thunderstorms across the region during the
afternoon. Regardless of the expected afternoon conditions, expect
a mixture of sunshine and clouds throughout the morning.
Additionally, some instability aloft, from the divergence side of
a tilted trough, could enhance the development of isolated
thunderstorm. Given the expected conditions and the already
saturated soils, urban and small stream flooding is expected
today. We cannot rule out isolated flash flooding.

As the upper-level trough moves out of the region, a mid-level ridge
will promote more stable conditions for the rest of the short-term
period. Meanwhile, at the surface, a veering in winds is forecast,
as the surface ridge moves eastward into the Central Atlantic, in
response to another frontal boundary exiting the Eastern Seaboard.
Under the influence of a generally stable pattern and moderate
east-southeasterly winds, passing showers are anticipated each
day in the morning and evening hours across the U.S. Virgin
Islands and the east and northeast sections of Puerto Rico.
Afternoon convection will affect the northwestern quadrant and the
San Juan Metro area. Late Saturday, a more south-southeasterly
wind flow is expected as the front approaches the region.

&&

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

By Sunday, a mid to upper-level trough will amplify from the
northwest across the Northeast Caribbean, while on the surface, an
old cold front with a pre-frontal trough will pool near to above-
normal moisture over the islands. The latest guidance suggests
unsettled weather conditions, especially Sunday, and a cool/dry
air mass filtering behind the front by late Sunday night or
Monday. Our confidence is moderate that urban and small stream
flooding with isolated flash floods will likely happen on Sunday.

If models are correct, winds will shift from the north-northwest
early Monday morning to the North-northeast late Tuesday morning
or Wednesday. Model guidance suggests dewpoint depression values
ranging from 15 to 20 units of Celsius difference with isolated
values up to 25 degrees in the layer between 1000 MB and 700 MB.
This air mass may result in little or no rain between Monday and
at least early Wednesday morning, when values will decrease to 15
or less, suggesting a few isolated showers. In addition, winds
should increase behind the front, creating breezy to locally windy
conditions, particularly early Monday morning. Nice and cool
tropical winter temperatures will also be possible through that
period.

Around mid-week (Thursday), a high surface pressure will promote
winds to return from the northeast to the east-northeast, pushing
fragments of moisture, once again, over the region and promoting
the typical seasonal weather pattern due to the advection of
moisture/passing showers.

&&

.AVIATION...
(06Z TAFS)

VFR conditions will prevail for all the TAF sites at least until
12/18z. Strong shower activity is anticipated and would result in
VCSH and SHRA across TISX, TJBQ, and TJSJ. The heaviest activity
will reduce the VIS and some VCTS are possibles over TJBQ around
12/19Z. Winds will remain VRB until 12/14Z, increasing from the E
at 10 kts with sea breeze variation.

&&

.MARINE...

The local buoy network detects wind waves with a period between 6
and 9 seconds and a significant wave height between 1 and 3 feet,
while the 41043 detects significant wave heights between 3 and 5
feet with a similar period. The San Juan and Rincon buoys
observed a small northerly swell with 14 seconds fading across the
Atlantic Waters and Mona Passage. Similar conditions will persist
through at least Sunday night when marine guidance suggests the
arrival of a northeasterly swell with a period between 10 and 11
seconds and a height between 6 and 8 feet. The Atlantic Offshore
Waters may need a Small Craft Advisory around Sunday night through
early next week.

Beachgoers, the risk of rip currents is low for the beaches south
of Rincon through Yabucoa and Vieques. Meanwhile, the risk is
moderate for the beaches from Rincon northward to Humacao,
Culebra, St Thomas/St John, and St Croix.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM/AVIATION...LIS
LONG TERM...CAM

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
433 AM AST Fri Jan 13 2023

.SYNOPSIS...

Expect a mixture of sunshine and clouds with the trades pushing
showers from time to time. Afternoon convection due to sea breeze
variations will promote periods of moderate rains across the
interior and western PR and downwind from the Virgin Islands. A
cold front approaching from the northwest of Puerto Rico could
promote unsettled weather conditions by Sunday. Conditions may
improve late Monday through at least Wednesday next week,
returning the pleasant tropical winter temperatures. An advective
pattern may return through the second part of next week.

&&

.SHORT TERM...Today through Sunday.

The remnants of a frontal boundary continue to provide plenty of
water content across the region, as suggested by the latest
precipitable water values Satellite Imagery. This water content
and the local effects will increase the potential for shower
activity across the local waters, mainly during the morning hours.
As the day progresses, the diurnal heating, in combination with
the sea breeze, will bet for another active afternoon, mainly
across the west side of Puerto Rico. Despite the anticipated
shower activity, faster showers due to moderate winds will result
in less rainfall accumulations.

Surface conditions will change rapidly on Saturday as a cold front
exiting the Eastern Seaboard sinks southeastward into Central
Atlantic. This surface feature will induce a veering in winds.
Caribbean moisture will reach the local islands, embedding in the
southerly wind flow, causing the potential for widespread shower
activity for most of the area, but especially across the northern
and interior sections. As the frontal boundary moves further into
the region, deteriorating conditions will expand on Sunday.
Additionally, at the upper levels, the associated mid to upper-
level trough will induce divergence aloft and colder temperatures
at 500 MB. The combination of the above conditions will provide
cloudy skies for all local islands for most of the day,
accompanied by scattered to numerous showers across all the north
and northeastern sections. Therefore, residents and visitors can
expect periods of heavy rain with isolated thunderstorms,
resulting in urban and small stream flooding. Also, isolated flash
flooding cannot be ruled out with the heaviest activity,
especially across the San Juan metro area.

&&

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

After the possible frontal passage (FROPA), the latest model
guidance maintains good moisture across some areas of PR and the
USVI, which could promote unsettled weather over the interior,
south and east PR, the USVI, and local Caribbean Waters during the
afternoon. Regarding the dry air that could filter over the
Atlantic Waters and northwest and western PR. The FROPA will shift
the winds from the north on Monday, north-northeast Tuesday, and
return from the northeast by Wednesday. In addition, winds should
increase behind the front, creating breezy to locally windy
conditions, particularly early Monday morning. Nice and cool
tropical winter temperatures will also be possible through that
period. Now, the current model guidance suggests little or no rain
on Tuesday.

As the trade winds return, fragments of moisture will arrive by
Wednesday onward, promoting the typical trade wind showers across
the windward sections. A mid-level high pressure will limit the
vertical development promoting dry air aloft. However, cold air
advection over warmer waters will enhance these trade wind showers
each night and early morning. Periods of sunshine and clouds may
be observed each morning, followed by afternoon convection across
the interior and southwest sections each afternoon.&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions will prevail for all the TAF sites.
Winds will remain VRB until 13/14Z, increasing up to 12 kts from the
E and with sea breeze variation. VCSh will prevail for most eastern
sites in the morning hours & SHRA and VCTS are possible across the
NW sections at around 13/19Z.

&&

.MARINE...

The local buoy network detects wind waves with a period between 5
and 8 seconds and a significant wave height between 1 and 3 feet,
while the 41043 detects significant wave heights between 4 and 5
feet with 9 seconds from the east-northeast. The San Juan and
Rincon buoys observed a small northerly swell with 14-10 seconds
across the Atlantic Waters and Mona Passage. Similar conditions
will persist through at least Sunday night when marine guidance
suggests the arrival of a northeasterly swell with a period
between 10 and 11 seconds and a height between 6 and 8 feet with
occasional seas up to 10 feet. The Atlantic Offshore Waters may
need a Small Craft Advisory around Sunday night through early next
week.

Beachgoers, the risk of rip currents is low for the beaches south
of Rincon through Yabucoa and Vieques. Meanwhile, the risk is
moderate for the beaches from Rincon northward to Humacao,
Culebra, St Thomas/St John, and St Croix.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM...LIS
LONG TERM....CAM
AVIATION...LIS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
417 AM AST Sat Jan 14 2023

.SYNOPSIS...The frontal boundary will continue to approach the
forecast area from the northwest, and will affect the region
Sunday into Monday. Active weather is expected for the beginning
of next week, with the increase in the shower activity today.

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

A polar trough will continue to exit the eastern coast of the United
States, escorting a cold front into the northeastern Caribbean. As
the frontal system approaches, the winds from the surface into the
mid levels of the atmosphere will shift from the southeast. In the
meantime, a patch of moisture will approach from the Leeward
Islands, converging over the local islands, and increasing shower
activity, especially in and around the Virgin Islands and
southeastern Puerto Rico. As the front continues to approach late
Saturday, the winds will veer from the south, and will continue to
gradually shift clockwise until becoming north-northeast on Monday.
The latest guidance has the bulk of the rain approaching the Mona
Channel late Saturday and early Sunday. Therefore, the shower
activity should reach the west and northwest sections of Puerto Rico
on Sunday, crossing Puerto Rico during the day, and reaching the
Virgin Islands late Sunday into Monday.

Although the front is expected to move fast, moderate to locally
heavy rainfall can be anticipated, with an elevated risk for
flooding anticipated, as well as mudslides in areas of steep
terrain. For the main island of Puerto Rico, conditions should
improve by Monday, with a drier air mass moving in and cooler
temperatures expected. The clouds and showers should linger a little
longer over the Virgin Islands, although with the heaviest activity
staying just south of St. Croix by late Monday.

&&

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

The inherited forecast remains on track. The latest model
guidance continues to suggest little or no rain on Tuesday
as the cold front continues to move across the forecast area.
Nevertheless, patches of moisture embedded within the trade
winds will reach the local islands from Wednesday onward,
promoting the typical trade wind showers across the windward
sections. The cold air advection over warmer waters will enhance
these trade wind showers each night and early morning. Therefore,
expect periods of sunshine and clouds each morning, followed by
the afternoon convection across the interior and western to
southwestern quadrant each afternoon. Nonetheless, the vertical
development of this rainfall activity will remain limited due to a
mid-level high pressure that is promoting dry air aloft. With the
passage of this cold front, nice and cool tropical winter
temperatures will spread across the forecast area, at least
through the end of the period.

&&

.AVIATION...Mainly VFR conditions expected for the forecast period.
SHRA expected to increase in frequency during the period around
the USVI terminals. After 17Z, SHRA are also expected to develop
along TJBQ, with brief periods of reduced VIS and low ceilings.
Winds will be from the SE at 10 knots through 18Z, gradually
shifting from the south between 18Z-21z, and from the west-
southwest afterward.

&&

.MARINE...No change from previous forecast. Relative tranquil seas
will continue today, before the arrival of a northwesterly swell
late on Sunday. Light southerly winds are expected today.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM...ERG
LONG TERM....MMC
AVIATION...ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
423 AM AST Mon Jan 16 2023

.SYNOPSIS...

Expect the residual moisture from the cold front that
moved across Puerto Rico to linger through the morning hours.
Today, the USVI, should begin to experience the rainfall activity
as the front moves across. A northwesterly swell now over the
region will continue to affect marine and coastal conditions
through at least midweek.

&&

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

The cold front has crossed the islands, leaving a layer of low level
clouds across the skies of Puerto Rico and the northern USVI. Shower
activity, however, will linger in the vicinity of St. Croix through
tomorrow, although the accumulations should stay in the light to
moderate side. After the frontal passage, the circulation of a high
pressure centered near Florida and a low pressure a couple hundred
miles east of Virginia will promote a northerly wind flow over the
islands through Tuesday. Along with these winds, the air mass will
become drier, with precipitable water values falling down from 1.5 on
Monday to 1.1 inches on Tuesday. As a result, generally fair weather
is expected to prevail through this period. However, even under the
influence of the drier air mass, northerly winds tend to promote
advective showers along northern Puerto Rico, so a shower or two
cannot be ruled out.

As the high pressure migrate eastward, the winds will shift from the
northeast late Tuesday and on Wednesday while strengthening. The
remnants of the cold front will be dragged by the trade winds over
the northern USVI and eastern Puerto Rico, increasing the
probability of showers. Additionally, 1000-850 mb thicknesses will
be below normal, meaning that temperatures should stay below normal
as well, reaching the upper 70s and low 80s at coastal areas, and
the low to mid 70s in the mountains. At night, lows will drop into
the 50s and low 60s in the mountains, and upper 60s to low 70s at
lower elevated areas.

&&

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

On Thursday, expect patches of moisture embedded within the trade
winds to promote the typical trade wind shower activity across
Puerto Rico and the U.S. Virgin Islands. A similar weather pattern
will prevail throughout the period. The cold air advection over
warmer waters will enhance trade wind showers each night and early
morning. Periods of cloudy skies are forecast, although sunny
skies are anticipated from time to time. The mixture of cloudy and
sunny skies will be followed by the afternoon convection across
the interior and western quadrant of Puerto Rico each afternoon.
Like in previous discussions, the vertical development of any
rainfall activity will remain limited due to a mid-level high
pressure promoting dry air aloft. At this time, PWAT models
suggest moisture content fluctuating below 1 inch and up to 1.30
inches at times. Latest model guidance shows an upper-level TUTT
inducing a trough at the surface and causing an increase in
rainfall activity by the end of the weekend into the beginning of
the workweek. Temperature-wise, expect the nice and cool tropical
winter temperatures to spread across the forecast area, at least
through the end of the period.

&&

.AVIATION...Mainly VFR conditions expected. A cold front lingers across
the area, bringing periods of SHRA across the USVI terminals and
TJSJ. Periods of reduced VIS and low ceilings will be possible.
SHRA should dissipate after 14Z for TJSJ, but VCSH will continue
for the USVI throughout the forecast period. Winds will be out of
the north to northeast, at 10-13 knots, and stronger gusts.

&&

.MARINE...A northwesterly swell will continue to enhanced hazardous
seas and coastal conditions through at least mid-week. For more
details we encourage you to visit the CFWSJU and MWWSJU products.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Wednesday night for PRZ001-
002-005-008-010.

High Surf Advisory until 6 AM AST Wednesday for PRZ001-002-005-
008-010-012.

High Rip Current Risk through late Wednesday night for PRZ011-
012.

VI...High Surf Advisory until 6 AM AST Wednesday for VIZ001.

High Rip Current Risk through late Wednesday night for VIZ001.

High Rip Current Risk from this evening through late Wednesday
night for VIZ002.

AM...Small Craft Advisory until 2 PM AST Wednesday for AMZ710-712-741-
742.

Small Craft Advisory from 8 AM this morning to 2 PM AST
Wednesday for AMZ715.

Small Craft Advisory from 8 AM this morning to 8 AM AST Tuesday
for AMZ745.

$$

SHORT TERM...ERG
LONG TERM....MMC
AVIATION...ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
419 AM AST Tue Jan 17 2023

.SYNOPSIS...

Cooler temperatures and drier air will prevail across the area
today. Generally fair weather is expected to prevail for the next
couple of days. Hazardous marine and coastal conditions are
expected to persist, due to a northwesterly swell that has moved
into the local waters.

&&

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

The cold front that moved through the islands on Sunday now lingers
well south of the Virgin Islands, with part of the moisture field
covering St. Croix and patchy clouds across the islands. The most
recent precipitable water values derived from GOES-16 show less than
one inch for western Puerto Rico, increasing to 1.4 near St. Thomas
and 1.6 near St. Croix. This moisture is mainly capped below 850 mb,
due to a building ridge over the western Caribbean promoting a drier
air mass above these levels. At the surface, the trade winds are
being steered by a high pressure now centered east of Florida,
coming out of the northeast at 10 to 15 knots. The National Blend
Model (NBM) has higher amounts of rain than either of the most used
global models (GFS and ECMWF). Based on current observations, it
looks like that the GFS and ECMWF have a better grab of reality, and
the forecast was based on these models. Therefore, generally fair
weather is expected to prevail with only very brief and light
showers moving over sections of northeast Puerto Rico at times.

As the high pressure migrates eastward, fragments of moisture from
the front will be pushed back into the islands by late Wednesday and
Thursday. This should increase the frequency of showers a little,
mainly for the USVI and eastern Puerto Rico. However, due to the
lack of dynamics at the mid and upper levels, the rain amounts are
not expected to be of concern.

&&

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

By the end of the workweek, expect the dry air to prevail across
Puerto Rico and the U.S. Virgin Islands. Nevertheless, expect the
patches of moisture embedded within the trade winds to promote
the typical trade wind shower activity across the region. The cold
air advection over warmer waters will still enhance trade wind
showers each night and early morning. Periods of cloudiness and
sunny skies are still anticipated throughout the period. The
mixture of cloudy and sunny skies will be followed by the
afternoon convection across the interior and western quadrant of
Puerto Rico each afternoon. Once again, the development of any
rainfall activity will be limited because there is a mid-level
high pressure promoting dry air aloft. Model guidance continues
showing an upper-level TUTT inducing a trough at the surface and
causing an increase in rainfall activity by the end of the weekend
into the beginning of the workweek but nothing significant. From
Sunday onwards, the patches of moisture are expected to move fast
across the area due to an anticipated increase in winds.
Temperature-wise, expect the nice and cool tropical winter
temperatures to spread across the forecast area throughout the
period.

&&

.AVIATION...Mainly VFR conditions expected to prevail. BKN layers will
remain from FL040-FL060 through 22Z as a frontal boundary lingers
south of the islands. No significant operational impacts expected
from the front for the PR terminals, but SHRA could develop at
times around TISX. Winds will be out of the NE at 11 to 14 knots,
with gusts around 20 knots for the USVI terminals.

&&

.MARINE...Hazardous seas and life-threatening rip currents will
continue through late midweek due to the combination of a
northerly swell and wind driven seas. Moderate to locally fresh
north-northeasterly winds will continue across the regional
waters. For more details we encourage you to visit the CFWSJU and
MWWSJU products.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Thursday afternoon for PRZ001-002-
005-008-010>012.

High Surf Advisory until 6 AM AST Thursday for PRZ001-002-005-
008-010-012.

High Rip Current Risk from this evening through Wednesday
afternoon for PRZ013.

VI...High Rip Current Risk through Thursday afternoon for VIZ001-002.

High Surf Advisory until 6 AM AST Thursday for VIZ001.

AM...Small Craft Advisory until 8 AM AST Thursday for AMZ710.

Small Craft Advisory until 2 AM AST Thursday for AMZ712-715-741-
742.

Small Craft Advisory from 8 PM this evening to 8 PM AST
Wednesday for AMZ722.

Small Craft Advisory until 2 AM AST Wednesday for AMZ745.

&&

$$

SHORT TERM...ERG
LONG TERM....MMC
AVIATION...ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
419 AM AST Wed Jan 18 2023

.SYNOPSIS...

Weather-wise, drier and stable conditions will prevail today.On
Thursday into the upcoming weekend, pockets of moisture embedded
in the trade winds will increase the potential for shower activity
across the local islands. Hazardous marine and coastal conditions
will prevail for the next several days.

&&

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

A surface high pressure centered east of the Bahamas will maintain
winds out of the northeast today. At the mid levels, a ridge also
dominates, maintaining a strong trade wind cap inversion at 850 mb,
and a dry air mass above these levels. In fact, recent satellite
imagery from GOES-16 shows precipitable water values of only 0.82
inches, which is near 2 standard deviation below normal. Therefore,
mainly fair weather is expected, and the probability of precipitation
(PoPs) where adjusted a bit downward for today.

As the surface high migrates eastward, the winds will shift from the
east on Wednesday, and the remnants of the cold front that brought
unsettled weather last Sunday will retrograde into the islands. The
trade winds will then drag some showers over the Virgin Islands, and
also over eastern Puerto Rico. This activity is expected to be
limited, since the mid level ridge continues to hold. A similar
pattern is expected on Thursday, with additional patches of moisture
moving through, generating advective showers for the eastern half of
the area of responsibility, and the potential for convection over
the west in the afternoon hours.

&&

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

The forecast remains unchanged. The latest model guidance shows
a surface trough across the forecast area at least through the
weekend. Therefore, expect a slight increase in patches of
moisture. From Sunday onwards, winds will increase slightly,
meaning that the showers should move quickly over the region.

During the workweek, trade winds showers will promote the typical
shower activity across Puerto Rico and the U.S. Virgin Islands.
The potential for afternoon convection across the interior and
western quadrant of Puerto Rico each afternoon is still
anticipated due to the advective showers. However, the
development of any rainfall activity will be limited, mainly due
to a mid-level high pressure that continues to promote dry air
aloft. Temperature-wise, expect nice and cool tropical winter
temperatures across the forecast area.

&&

.AVIATION...VFR conditions prevailing through the forecast period.
SHRA activity should remain limited, mainly over the Atlantic
waters. However, no impacts to operations is expected. FL050 winds
will be out of the NE at 4 to 11 knots, with stronger gusts at
times.

&&

.MARINE...Hazardous seas and life-threatening rip currents will
continue due to the combination of a northwesterly swell and wind
driven seas. Moderate to locally fresh northeasterly winds will
continue across the regional waters. For more details we encourage
you to visit the CFWSJU and MWWSJU products.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Saturday afternoon for PRZ001-002-
005-008.

High Surf Advisory until 6 AM AST Thursday for PRZ001-002-005-
008-010-012.

High Rip Current Risk through Thursday afternoon for PRZ010-013.

High Rip Current Risk through late tonight for PRZ011.

High Rip Current Risk through late Thursday night for PRZ012.

VI...High Surf Advisory until 6 AM AST Thursday for VIZ001.

High Rip Current Risk through Thursday afternoon for VIZ002.

High Rip Current Risk through late Thursday night for VIZ001.

AM...Small Craft Advisory until 8 AM AST Thursday for AMZ710.

Small Craft Advisory until 2 AM AST Thursday for AMZ712-715-741-
742.

Small Craft Advisory until 8 PM AST this evening for AMZ722.

&&

$$

SHORT TERM...ERG
LONG TERM....MMC
AVIATION...ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
420 AM AST Thu Jan 19 2023

.SYNOPSIS...Today's main hazard risks are life-threatening rip
currents for beachgoers and choppy marine conditions for small
craft. Unfavorable conditions aloft and below normal moisture
content will promote generally fair weather conditions during the
next few days. A gradual increase in the general wind flow will
result in breezy to windy conditions by Friday into the weekend.


&&

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

Upper level ridge will remain in place overhead while
a trough east of the region is forecast to become more amplified
over the northern Leeward Islands. Mid level ridge will however
strengthen and build across the region to maintain stable conditions
aloft during the period. A surface high pressure ridge will
gradually build north and east of the region later today and
through the period, while a weakly induced surface trough crosses
the local islands accompanied by a patch of shallow moisture from
an old frontal boundary. Some associated trade wind showers will
continue to reach portions of the north and east sections of the
islands this morning but no significant rainfall amounts are
anticipated. For the rest of today and due to the fairly dry and
stable airmass in place expect limited afternoon shower activity.
This should be mainly over parts of the interior and west to
southwest sections of Puerto Rico and over the coastal waters and
downwind of the USVI and the adjacent islands.

For the rest of the period, expect the easterly winds to gradually
increase on Friday and Saturday as the surface ridge builds north of
the region resulting in a slight tightening of the local pressure
gradient. Overall dry and stable conditions will however persist
aloft and therefore expect more of a seasonal weather pattern with
cool overnight low temperatures and near normal daytime highs.
Mostly fair weather skies should prevail except for isolated to
scattered showers of short duration along with somewhat breezier
conditions during the day on Friday and Saturday.


&&

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

Based on the most recent model guidance, fair and relatively dry
weather conditions will prevail through the long-term forecast
period. A mid-to-upper level ridge will remain the dominant
feature over the northeastern Caribbean, maintaining a strong
trade-wind cap and hostile conditions for deep convective
development. At the surface, occasional low-level moisture patches
embedded in the trade winds will bring passing showers into
eastern Puerto Rico and the U.S. Virgin Islands, with increasing
easterly winds at 10-20 mph steering some showers further inland
at times. Even with rainfall totals from afternoon shower
development over western Puerto Rico, rainfall accumulations
should remain minimal throughout the cycle. Pleasant temperatures
will prevail across the local islands, ranging from the mid 50s
across higher elevations at nighttime to the mid 80s across
coastal and urban areas at daytime.


&&

.AVIATION...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 calm to light and variable with land breezes
bcmg fm E-NE 5-15 kts with sea breeze variations aft 19/14Z. No sig
operational wx impacts fcst for local terminals.


&&

.MARINE...Although the northwesterly swell and winds will
continue to subside, choppy seas and life-threatening rip currents
conditions will continue today. Small craft should exercise
caution mainly across the Atlantic waters and Mona Passage, where
seas will peak around 6 feet with occasional seas up to 8 feet.
Elsewhere, seas will remain below 5 feet. Increasing winds will
promote choppy marine conditions for small craft by Friday into
the weekend.

For beachgoers, the risk of life-threatening rip currents will
remain high for most north-facing beaches of Puerto Rico, Vieques,
Culebra, and the U.S. Virgin Islands.


&&

.FIRE WEATHER...Despite relative humidities expected to fall into
the lower 40s and within fire danger thresholds between the late
morning and early afternoon hours, winds should remain below 15
mph across local fire-prone areas. As a result, today's fire
weather hazard risk should remain low.

However, since the general wind flow, and current limiting
factor, is expected to increase by Friday into the weekend,
elevated to briefly critical fire weather hazard risks are
possible if conditions remain as dry as previous days.


&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Friday night for PRZ001-002-
005-008.

High Rip Current Risk through late tonight for PRZ010-012.

VI...High Rip Current Risk through late tonight for VIZ001-002.

AM...None.
&&

$$

SHORT TERM...RAM
LONG TERM....ICP
AVIATION...RAM
PUBLIC...ICP

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
407 AM AST Fri Jan 20 2023

.SYNOPSIS...Today's hazard risks are winds, marine conditions,
and rip currents. Beachgoers and small craft should remain alert
for hazardous and life-threatening conditions. Despite occasional
patches of moisture streaming across the region, unfavorable
conditions aloft for deep convective development and moisture
deficiencies, which is typical for this season, will maintain
generally fair weather conditions during the next few days.
Increasing winds will keep or elevate current hazard risks
through the weekend. A persistent drying pattern may boost the
fire danger hazard risk during the next few days.

&&

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

A mid to upper level ridge will continue to build and hold across
the region through the period to maintain dry and stable condition
aloft. Meanwhile a trough east of the region extending across the
Northern Leeward islands is forecast to become amplified and sink
southwards into the southeastern Caribbean. A surface high pressure
ridge will continue to build north of the region and remain the
dominant weather feature for the next several days. As a result,
expect increasing easterly winds and overall breezy conditions,
especially along the coastal areas and over the coastal waters. For
the rest of the morning hours, a few patches of shallow trade wind
moisture will bring mainly isolated showers over the coastal waters
with very little of no precipitation expected to reach the islands.
Another day of pleasant weather and mostly sunny skies can be
expected with limited afternoon showers across the islands. Seasonal
temperatures and no major weather impacts are so far forecast for
today.

For the rest of the period, other than the aforementioned increasing
easterly winds due to the building surface ridge over the Atlantic;
overall dry and stable conditions will persist with a seasonal
weather pattern and no significant weather feature forecast based on
recent model guidance and the overall weather pattern. Cool
overnight low temperatures and near normal daytime highs can
therefore be expected. Mostly fair weather skies will prevail,
except for brief periods of isolated to scattered nocturnal trade
wind showers over the coastal waters, followed by sunny and fair
weather skies with limited shower activity over parts of the
interior and west sections of Puerto Rico each afternoon. Lesser
shower activity if any at all is so far forecast for the U.S. Virgin
Islands, where sunny skies and breezy conditions are expected to
prevail.

&&

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

Fair and relatively dry weather conditions will prevail through
the long-term forecast period, as suggested by the most recent
model guidance, which has not changed in recent days.

An eastward migrating mid-to-upper-level ridge will remain the
dominant feature over the northeastern Caribbean, maintaining a
strong trade-wind cap and hostile conditions for deep convective
development. Occasional low-level moisture patches embedded in the
trade winds will briefly bring moisture levels to seasonal values
of around 1.3 inches by Tuesday morning, promoting an increase in
passing showers across the waters moving inland into eastern
Puerto Rico and the U.S. Virgin Islands. Persistently moderate to
fresh easterly wind flow at 10-20 mph will push some showers
further inland; the same flow that will carry the remnants of an
old frontal boundary into the area by the end of the workweek,
resulting in slightly higher shower coverage by Thursday night
into Friday. Despite any shower activity observed, rainfall
accumulations should remain minimal. Tropical winter temperatures
will persist across the local islands, ranging from the lower 50s
across higher elevations at nighttime to the mid 80s across
coastal and urban areas at daytime.

&&

.AVIATION...VFR conds durg prd at all terminals. SCT lyrs nr
FL025...FL040...SKC ABV. ISOLD -SHRA/SHRA en route btw the local
islands and ovr the regional waters. SFC wnds calm to light and
variable bcmg fm east 12 to 15 kts with some enhanced sea breeze
variations and occasionally higher gusts btw 20-25 kts psbl aft
20/14Z. Low level wnds fm ENE btw 15-20 kts BLO FL250. No sig
operational wx impacts fcst for local terminals.

&&

.MARINE...Moderate to locally fresh easterly winds will maintain
choppy marine conditions today. Small craft should continue to
exercise caution, mainly across the local passages, where winds in
the 15-20 knots range could generate locally choppy seas.
Elsewhere, seas will remain below 5 feet and winds at 15 knots or
below.

For beachgoers, the risk of life-threatening rip currents will
remain high for most north-facing beaches of Puerto Rico and Saint
Croix.

&&

.FIRE WEATHER...Today's fire weather danger hazard risks should
remain low, mainly due to KBDI values still below 550 across primary
reporting sites. However, the drying pattern will continue, and
all fire danger criteria thresholds may come into place within the
next few days.

Aided by the sea breeze, local winds should persistently peak into
the 15-20 mph range during the late morning and early afternoon
hours. In contrast, relative humidity values may plunge into the
lower 40s as drier air continues to invade the area. Still, a
southerly component generated by the same sea breeze may locally
enhance moisture levels despite the drier air presence. Without
the influence of the sea breeze and continued lack of wetting
rains, this combination could boost the fire weather danger hazard
risk between this weekend and early next week.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk from 6 AM AST this morning through late
tonight for PRZ001-002.

High Rip Current Risk from 6 AM AST this morning through
Saturday afternoon for PRZ005-008.

VI...High Rip Current Risk from 6 AM AST this morning through
Saturday afternoon for VIZ002.

AM...None.
&&

$$

SHORT TERM...RAM
LONG TERM....ICP
AVIATION...RAM
PUBLIC/TRANSLATIONS...ICP

[cycloneye]

796
FXCA62 TJSJ 210815
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
415 AM AST Sat Jan 21 2023


.SYNOPSIS...
A mid to upper level ridge will be the dominant feature into the early
part of next week and therefore maintain dry and stable conditions aloft.
Meanwhile, the Atlantic surface high pressure ridge will continue to
build north of the region, tightening the local pressure gradient and
consequently increasing the easterly trade winds. Choppy marine conditions
due to the moderate to locally fresh easterlies will therefore persist.
An overall seasonal weather pattern is forecast for the rest of the
weekend with limited shower activity expected over and around the islands.
Impacts and potential hazard risks for today through Sunday are the
increasing trade winds, choppy marine conditions, and a moderate to
high risk of rip currents for most of the north and east facing beaches.

&&


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

Despite a few patches of low-level moisture streaming across the
region, the weather scenario during the short-term forecast cycle
will remain relatively dry and favorable for outdoor activities,
with no expected weather-related hazards. The patches mentioned
above, positioned by GOES-16 satellite imagery in an area stretching
from the Leeward Islands eastward into the tropical Atlantic, will
occasionally increase moisture levels to typical seasonal values of
around 1.2 inches. Still, the region will be mainly dominated by
pockets of drier air, with precipitable water values falling as low
as 0.8 inches on Sunday. On top of this, an eastward migrating mid-
to-upper level ridge will anchor north of the region and become the
dominant feature, providing stability while setting a strong trade
wind cap and hostile conditions for deep convective development over
the area. Thus, expect limited shower activity. Any rainfall
accumulations observed during the next few days will be mainly the
result of isolated to scattered passing showers moving inland from
the waters over eastern Puerto Rico and the US Virgin Islands,
particularly during the overnight and early morning hours. Afternoon
convective development may produce minimal rainfall accumulations
along the far western sections of Puerto Rico, but chances are
slight.

Pleasant temperatures will prevail, ranging from the lower 50s
across higher elevations at nighttime to mid 80s across coastal and
other urban areas at daytime. Surface winds will remain easterly,
reaching the 10-20 mph range with higher gusts and sea breeze
variations early in the afternoon but becoming calm to light and
variable at nighttime, dominated by land breezes. Breezy to windy
conditions will also prevail during the next few days, with an
additional increase in wind speeds to around 20-25 mph by Sunday
onwards, mainly across coastal areas of southern Puerto Rico and the
local islands.

&&

.LONG TERM...Tuesday through Sunday...

Recent model guidance and the present weather pattern both suggest
a seasonal weather pattern is expected Tuesday into Wednesday, with
only occasional patches of shallow low level moisture and passing
showers forecast during the overnight hours followed by limited
shower activity during the day. Mostly fair and pleasant weather
conditions will prevail across the region.

By the latter part of the period, expect a change in the overall
pattern due to the approach of a weak easterly trough late Wednesday,
followed by a cold frontal boundary by late Thursday into Friday.
Thereafter a surface high pressure ridge is forecast to build across
the west Atlantic resulting in an increase in the northeasterly wind
flow. This in turn will aid in pushing the remnants of the aforementioned
frontal boundary across the area while increasing low level moisture
convergence and promoting better potential for shower development.
In addition, the slight erosion of the mid to upper level ridge is
also expected due to a polar trough forecast to move eastward across
the Atlantic during the same time. Therefore the best potential for
increase shower activity at this time is Thursday into Friday. A
gradual improvement and return of the seasonal pattern is expected
by late Friday into the following weekend. By then, moisture transport
is expected to erode once again and the mid to upper level ridge
as well as the surface high pressure will build across the region
favoring mostly fair weather condition with less frequent shower
activity. Typical winter season temperatures will persist ranging
from the low to mid 50s across higher elevations at nighttime to
the mid 80s across coastal and urban areas.

&&

.AVIATION...
VFR conditions will prevail across all terminals during the next
24 hours. Calm to light and variable winds gradually becoming easterly
and increasing to 10-20 mph after 21/14Z with higher gusts and sea
breeze variations. Winds will once again become calm to light and
variable after 21/22Z.

&&

.MARINE...
Moderate to locally fresh trade winds will maintain choppy marine conditions
mainly across portions of the offshore waters and the local passages.Increasing
trade winds are expected for Sunday onwards, resulting in deteriorating
wind driven sea condition for portions of the local waters and passages.
Please refer to the latest Coastal Waters Forecast (CWFSJU) issued
by WFO San Juan PR for the latest updates on the marine conditions.

A moderate risk of rip currents remains in place for all north and east
facing beaches of Puerto Rico, Culebra and Vieques. There is however
a high risk of rip currents for some of the north and east facing beaches
of St Croix and a moderate risk for most of the remaining beaches of
the U.S. Virgin Islands.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...High Rip Current Risk through this afternoon for VIZ002.

AM...None.
&&

$$

SHORT TERM...ICP
LONG TERM....RAM
AVIATION...ICP

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
339 AM AST Sun Jan 22 2023



.SYNOPSIS...
A mid to upper level ridge will remain the dominant feature through
Tuesday to maintain dry and stable conditions aloft. Surface high
pressure ridge will remain north of the region to maintain a moderate
east to northeast wind flow. Choppy marine conditions can be expected
across much of the local waters and passages for the next several days.
A seasonal weather pattern is forecast through the middle of the upcoming
week with limited shower activity expected across the islands and coastal
waters. Impacts and potential hazards for today through Tuesday will
be breezy conditions especially during the afternoon hours, choppy seas
and a moderate risk of rip currents for most of the local beaches except
for the protected beaches along portions of the south and west coasts
of Puerto Rico.

&&

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

No significant changes within the expected weather pattern during
the next few days and persisting dry and stable conditions will
support generally fair weather and favorable conditions for outdoor
activities, with no anticipated weather-related hazards. This
pattern results partly from a mid-to-upper-level ridge settling just
north of the region, maintaining hostile conditions for deep
convective development with a solid trade wind cap inversion around
the 800-850 mbar layer and drier air entrainment aloft. At the
surface, a developing high pressure anchoring just north of
Hispanola will cause the tightening of the local pressure gradient
while promoting increased trade winds. Under this general wind flow,
a few patches of low-level moisture will stream across the region,
with precipitable water briefly reaching the lower end of typical
seasonal levels at around 1.2 inches on Sunday. After that, a
decline in precipitable water will quickly follow, falling to about
0.8 inches or two standard deviations from typical seasonal values
by Monday into Tuesday as an extended patch of drier air moves into
the area. Any rainfall accumulations observed during the next few
days will be minimal and focused over eastern Puerto Rico and the US
Virgin Islands during the overnight and early morning hours.
Afternoon convective development may also produce minimal rainfall
accumulations along the far western interior to western sections of
Puerto Rico, but chances are slight.

Typical seasonal temperatures will prevail, ranging from the lower
50s across higher elevations at nighttime to mid 80s across coastal
and other urban areas at daytime. Breezy conditions will also
persist during the next few days, with easterly winds peaking around
10-20 mph and occasionally higher due to sea breeze variations early
each afternoon, mainly across coastal areas of southern Puerto Rico
and the local islands. Winds will become light and variable at
night, dominated by land breezes.

&&

.LONG TERM...Wednesday through Monday...

Recent model guidance and the overall weather pattern continued
to suggest a seasonal weather pattern with the typical periods of
passing low level cloud fragments and occasional showers during
the late evening and early morning hours but mainly over the coastal
waters. However by Wednesday night and early Thursday a weak easterly
disturbance and patch of moisture will quickly cross the area accompanied
by a wind surge a brief quick passing showers. Mostly fair and pleasant
weather conditions will prevail across the region thereafter except
for isolated to scattered afternoon showers mainly on the west end
and downwind of the islands.

By late Thursday into Friday, the prevailing winds are forecast to
become northeasterly as the Atlantic surface ridge builds and spreads
eastward over the west Atlantic, consequently increasing the northeast
wind flow. This will aid in pushing the remnants of a frontal boundary
across the area, thus increasing low level moisture convergence. A
slight erosion of the upper level ridge is also forecast as a polar
trough will cross the Atlantic just north and east of the region.
This overall scenario should favor and support the best potential
for some enhanced shower development especially during the afternoon
hours, and mainly over parts of the central interior and west
section of Puerto Rico. Lesser shower activity is forecast so far
the U.S.Virgin Islands where mostly sunny and fair weather skies
should prevail. Widespread and significant rainfall amounts are
not expected at this time during the period. A gradual improvement
and return of the limited shower activity is expected by late
Friday and through the following weekend, as trade wind moisture
will erode as the mid to upper level ridge as well as the surface
high pressure strengthens across the region favoring mostly fair
weather conditions. Some trade wind moisture returns on Monday as
the winds become more easterly and the trade winds increase once
again. Near seasonal temperatures are expected during the period
and should range from the upper 50s to low 60s across higher
elevations at night to the low to mid 80s across coastal and urban
areas.

&&

.AVIATION...
VFR conditions will prevail across all terminals during
the next 24 hours. Calm to light and variable winds gradually
increasing after 22/14Z to 15-20 mph around 22/18Z with higher gusts
and sea breeze variations. Winds will once again become light and
variable after 22/22Z. Impacts from occasional trade wind SHRA will
be brief and minimal.

&&

.MARINE...
Mariners can expect choppy seas up to 5 feet occasionally up to 6
feet over the offshore waters and most of the local passages, with
moderate to fresh east winds between 15 and 20 knots. Elsewhere and
in protected waters, seas between 1 to 4 feet. Small craft should
exercise caution across Offshore Waters and Caribbean Passages.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM...ICP
LONG TERM....RAM
AVIATION...ICP

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Mon Jan 23 2023

.SYNOPSIS...
A surface high pressure north of the region will support breezy
conditions over the next few days. Weak patches of moisture will
produce isolated to scatted showers and an increase of shower
activity is forecast for Friday as better moisture and a wind
surge enters the region. However, no significant rain producing
events are forecast for the near future. A moderate rip current
risk exist for mostly all of the beaches of PR and the USVI today.

&&

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

A surface high pressure is north of the area in the western
Atlantic. This will continue to drive trade winds across the area
from the east-northeast to east Monday and Tuesday. A cold front
will leave the eastern United States today but will not reach the
area as it sags south. The high behind it will continue to drive
the trade wind flow on Wednesday. Weak patches of moisture in the
flow will produce scattered showers--mainly on the eastern side of
Puerto Rico during the night and morning hours Monday and Tuesday
with increasing moisture late on Wednesday bring a few more
showers. The atmosphere above 7 kft is very dry and will continue
to be so through the period. This will keep vertical growth of
showers limited to less than about 10 kft. Nevertheless, some
minor convective activity with limited coverage is expected to
develop each day in western Puerto Rico and along the Cordillera
Central. Accumulations will be very limited.

At upper levels, a NW-SE oriented trough capped by a jet of up to 40-
50 knots will dig into the forecast area from the southeast and ease
south during the period. A few wisps of high clouds may be seen
during the period. Southwest flow at 250 mb will turn more westerly
during the period.

&&

.LONG TERM...Thursday through Tuesday...
A ridge continues to sit over the Eastern Caribbean with an axis
northeast of the region, remaining as the dominant feature that
is supporting breezy easterlies across the lower levels. This
flow will bring a patch of moist air to arrive early Thursday
morning, enhancing the chance of passing windward showers,
followed by a fair day of weather as drier air succeeds. However,
by early Friday morning, a noticeable band of post-frontal
boundary air and a wind surge will result in convergence of
moisture, raising precipitable water values to levels that should
support more shower activity. Most of the rainfall is expected
along the northern to eastern sections of Puerto Rico and the
northern USVI as breezy northeasterly winds prevail. No
outstanding rainfall amounts are expected, therefore flooding is
not much of a concern.

Conditions will improve by Saturday as drier air moves into the
region. During this time high pressure continues to prevail aloft,
providing generally stable conditions. This seasonal, fair
weather pattern is expected to last throughout the weekend until
Monday into Tuesday when the introduction of better moisture will
support an increase of showers. Overall, no significant rain
producing events are forecast for the near future. Temperatures
during this time will be around seasonal normals with mountainous
regions reaching down in the 50s/60s during the early morning
hours and coastal regions having lows in the 70s, followed by warm
afternoons across the islands each day.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. Land breezes of less than 6
kts over PR in easterly flow elsewhere of 10 kts or less bcmg
10-16 kts with sea breeze influences aft 23/15Z. Isold SHRA to
dvlp downstream of El Yunque and eastern islands and wrn PR with
brief MVFR CIGs psbl. Max winds E 25-32 kts btwn FL130-150 and
FL190-250.

&&

.MARINE...Seas are reaching up to 6 feet during the next few days
mainly due to moderate to locally fresh easterly winds. There will
be a lack of long period swell during the next week and wind wave
energy will become the primary wave group. Fair weather
conditions will prevail over the local waters, with a chance of
isolated to scatted showers from time to time. For beachgoers,
today there is a moderate rip current risk for most beaches of
Puerto Rico and the USVI, which will become high by midweek as
wind swell increases in strength.


.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM...WS
LONG TERM....RC

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
436 AM AST Tue Jan 24 2023

.SYNOPSIS...
Mostly quiet weather conditions will prevail with an increase of
shower activity on Wednesday as a frontal boundary moves over the
local area. Another burst of showers is expected on Friday and
after then precipitable water values will be slightly more
favorable for showers over the weekend into next week. Showers
during this time will be light and passing. Breezy conditions
will prevail over the next several days due to high pressure in
the Western Atlantic. The risk of rip currents is moderate today
for the local beaches, however will become high tomorrow for
several northern facing beaches of Puerto Rico.

&&

.SHORT TERM...Today through Thursday...
Surface high pressure is now squeezed between a cold front advancing
across the western Atlantic and another low pressure near 30 north
and 36 west. Its ridge extends southwest and then west across the
waters north of Puerto Rico at about 25 north. High pressure also
dominates the southeastern United States. This is causing surface
flow to be nearly easterly across the local area. Although the high
pressure over the southeast U.S. advances into the western Atlantic,
the front will make little progress south until Wednesday evening
and moderate to locally fresh surface winds will continue from the
east northeast. A lingering, but greatly attenuated, frontal
boundary will move southwest out of the Atlantic across the local
area on Wednesday and bring a slight increase in shower activity.

The airmass is very dry above the inversion, which will continue
around 5.7-6.0 Kft through the period, except on Wednesday
afternoon, when the moist layer may rise for a short while to around
10 Kft. This will keep showers from growing in any significant way
and keep showers light and passing. At upper levels, a broad trough
just off the coast of Brazil and Venezuela will sink south into
South America during the period. As it does so, winds at 250 mb will
gradually switch from southwest to northwest and diminish and a
ridge will build northeast across Hispaniola.

This configuration will keep mostly quiet weather over the area with
neither significant features nor heavy rain events occurring over
the area, but minor showers will continue periodically.

&&

.LONG TERM...Friday through Wednesday...
An enhancement of showers is expected on Friday morning as
northeasterly wind flow guides post-frontal boundary air over the
region. The combination of a moist lower to mid atmosphere and
breezy winds will produce showers across eastern and northern Puerto
Rico and the northern USVI. Most will be light and quick lived.
Afternoon convection across southwestern PR is possible due to
local effects and seabreeze convergence. The combination of dry
air prevailing above 700 mb and high pressure in the upper levels
across the Caribbean Basin is providing no concern for flooding
with this expected rain.

Meanwhile in the western Atlantic, high pressure squeezed between
two areas of low pressure continues to support breeze winds into the
weekend, then being replaced by a robust high on Sunday that will
raise wind speeds in excess of 20 knots. During this time another
swath of moist air moves into the region, supporting more showers
on Sunday. Again, this activity will be fairly light. For the
rest of the long term, a mix of patches of moist and dry air will
continue to fill the lower levels, supporting isolated to
scattered showers with light amounts of rainfall. Wind direction
will become more easterly by Monday as the area of high pressure
moves north of the region, with breezy conditions continuing
to prevail. This seasonal pattern is forecast out through
Wednesday, therefore expect a pleasant week of sunshine and light
showers.


&&

.AVIATION...VFR conditions are expected to prevail across the lcl
area thru 25/08Z. An area of mstr with isold -SHRA and CIGs BKN-
OVC065 is movg WNW across the area at 18 kt. Sfc winds bcmg E 12-18
kt with higher gusts and sea breeze variations through 21z, bcmg
land breezes less than 8 kt aft 24/22Z.

&&

.MARINE...Seas are generally below 6 feet and the main driver is
moderate to locally fresh easterly winds as a high pressure in the
Western Atlantic moves north of the region. This pattern will
continue for the next several days with the winds backing,
becoming northeasterly by Friday. Currently there is a moderate
risk of rip currents for the local beaches, however by tomorrow
the risk will become high for several beaches on the northern
coastline of Puerto Rico.

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.

&&

$$

SHORT TERM...WS
LONG TERM....RC

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Wed Jan 25 2023



.SYNOPSIS...
Breezy conditions continue to prevail due to a high pressure in
the western Atlantic. Some rain is expected in the mountains
during the next 24 hours, which could lead to ponding of water in
poorly drained areas. Friday, Sunday and Tuesday are forecast to
be standout days for weather as breezy winds push moist air over
the islands, however with no major amounts of rainfall to be
expected each day. There is a high risk of rip currents for
northern facing beaches of Puerto Rico until tonight mostly due to
wind generated short-period swell.

&&

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

A surface high pressure in the western Atlantic will generate east
northeast trade wind flow across the Caribbean. A weak cold front
now connected to the low pressure near 25 north 37 west is
approaching the forecast area from the east northeast and will
likely bring some additional shower activity to Puerto Rico and the
U.S. Virgin Islands this afternoon and tonight with its passage.
Winds will become a little more northeasterly and shower activity
will be enhanced by the orographic lift along the coast and over the
mountains. Nevertheless, expect amounts, in general, to be no
greater than one half inch in the mountains during the next 24 hours
ending at 26/12Z, and impacts limited to some ponding in poorly
drained areas. As the center of the high shifts northeast in to the
north central Atlantic, the northeast flow will continue. This will
bring a second slightly better cold front boundary through the area
on Friday morning. Showers will be a little better then. But,
showers in both cases will be very limited on the south coast of
Puerto Rico and only modest in the U.S. Virgin Islands where
orographic enhancement is weaker. Temperatures will be a few degrees
cooler across the area as the successive waves of cool air invades,
although these effects will also be limited on the leeward sides of
the islands.

The atmosphere at mid levels will be under the effects of a high
pressure just to the north and will be almost completely dry. The
effects of the upper level trough to our south and the modest jet up
to 50 knots around it will diminish through the period as a ridge
eases its way through Hispaniola. Both of these levels will be the
chief limiting factors in shower activity.

&&

.LONG TERM...Saturday through Thursday...

Breezy northeasterly winds will prevail in the lower levels as a
TUTT that is reflected down to the surface lingers east of the
region. However, a ridge continues to sit over the Caribbean,
maintaining generally stable conditions. Scattered showers are
forecast for Saturday morning as these breezy winds push the
moisture that is available, which is limited, over the near
coastal mountainous regions. A quiet weather pattern will follow
until Sunday afternoon when a robust high pressure at the surface
in the Western Atlantic causes surface wind speeds to reach in
excess of 20 knots, meanwhile advecting moist air into the
islands. The main activity will be wind driven showers which may
be consistent at times, possible causing ponding of water across
urban areas.

Wind driven showers remain the main weather feature into the new
week with an increase of quantity on Tuesday. As northeasterly flow
continues to prevail at this time, eastern and northern wind exposed
areas will receive the majority of rainfall. During this time the
nearness of an upper-level jet may begin to increase ventilation
aloft during Tuesday and Wednesday which would increase shower
frequency, however model guidance currently has the jet a good
distance from the islands. Also, precipitable water values on
Wednesday are projected to be limited so most likely a fair day
of weather is expected. Overall, a seasonal pattern of patchy
moisture moving in from breezy winds is to be expected. No
significant rain accumulations are forecast as high pressure in
the mid to upper-levels dominants, providing a stable local
atmosphere.

&&

.AVIATION...VFR conditions will prevail across the lcl area during
the next 24 hrs except in wrn PR and alg the Cordillera Central
where afternoon SHRA will produce MVFR conds with mtn topping. Winds
will be E-ENE at 10-16 kt with higher gusts and sea breeze
variations through 24/21z, becoming land breezes less than 6 kts in
PR and less than 10 kt in the USVI. Max winds W 36-46 kts btwn FL330-
375 diminishing during the day from the north.

&&

.MARINE...Moderate to fresh easterly winds will continue to
support sea heights around 5 feet today. Mostly wind generated
short-period east swell prevails as the dominant wave group and
then there is very small around 11-second northeast swell sourced
from a weak low in the Atlantic. This swell mix is producing
breaking wave heights of up to 6 feet along the northern coastline
of Puerto Rico, therefore a High Risk of Rip Currents statement
is in effect until late tonight (CWFSJU). Elsewhere the risk is
moderate. Weather conditions over the local waters will be mostly
clear with some isolated showers from time to time.


.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late tonight for PRZ001-002-005-
008.

VI...None.
AM...None.

&&

$$

SHORT TERM...WS
LONG TERM....RC

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
513 AM AST Thu Jan 26 2023

.SYNOPSIS...
Breezy conditions from the east-northeast will continue and there
will be an increase of shower activity later tonight and Friday.
Rainfall should be limited however poorly drained urban areas
might have some ponding of water. Surface wind flow will become
northeast Friday onward for the next several days. Temperatures
will be slightly cooler with this wind flow. There will be another
increase of showers on Sunday and then a similar pattern prevails
for the following week. There is a High Rip Current Risk
statement for northwestern beaches of Puerto Rico and the risk is
moderate mostly elsewhere for the local islands. Marine conditions
will deteriorate by Sunday.

&&

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

A surface high pressure in the western Atlantic is generating east
northeast trade wind flow across the Caribbean. An old frontal
boundary is approaching the forecast area from the northeast and
will likely bring some additional shower activity to Puerto Rico and
the U.S. Virgin Islands later tonight and Friday with its passage. A
low pressure with a central pressure of 1010 mb is near 24 north 37
west this morning. Winds will become a little more northeasterly and
shower activity will be enhanced by the orographic lift along the
coast and over the mountains. Nevertheless, expect amounts, in
general, to be no greater than one half inch in the mountains during
the next 48 hours ending at 28/12Z, and impacts limited to some
ponding in poorly drained areas. Another high pressure will leave
the eastern coast of the United States near South Carolina and move
into the western Atlantic on Saturday. This will keep flow in the
local area northeasterly and will bring in moisture from the
northeast around the low pressure which will be between 22 and 28
north and around 45 west Saturday to maintain light passing showers
across the local area. Temperatures will be a few degrees cooler
across the area as the cool air advection continues, although these
effects will also be limited on the leeward sides of the islands.

The atmosphere at mid levels will be under the effects of a slowly
retreating high pressure just to the northwest and will be almost
completely dry. The effects of the upper level trough to our south
will be replaced by a weak ridge by Friday evening. Both of these
levels will be the chief limiting factors in shower activity.


&&

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

A strengthening ridge in the western Atlantic will promote a
moist, breezy northeast flow on Sunday. In the mid-levels a ridge
dominants the Caribbean basin and is causing dry air to fill the
mid to upper levels, preventing any serious vertical motion. The
result will be a regime of passing showers that invade the
windward sections and local waters. Accumulations should be
limited however there may be the ponding of water for some poorly
drained urban areas. This pattern will continue into the week as
patchy moisture that was held up in a trough east of the region
becomes loose and advects over the islands in the northeasterly
flow. Dry air continues to prevail in the upper-levels throughout
the week, therefore vertically shallow passing windward showers
are all that is to be expected. During this time, temperature
will range in the 50s to 70s during the early morning hours and
warm up into the 70s and 80s during the afternoons, with respect
to mountainous and coastal regions.

&&

.AVIATION...VFR conditions will prevail across the lcl area during
the next 24 hrs. Sct -SHRA in N central coast of PR may induce lcl
CIGs AOB 030. Sfc winds will be NE at 12-18 kt with higher gusts and
sea breeze variations through 26/21z, becoming bcmg 6-12 kt and
diminishing afterward. Maximum winds 35-40 kts btwn FL400-415.

&&

.MARINE...Moderate to fresh easterly winds are creating choppy
conditions across the local waters, with winds becoming northeast
by tomorrow. This pattern will continue for the next several days
as another ridge builds in the western Atlantic over the weekend,
with sea heights rising in excess of 7 feet by Sunday. For today,
a mix of wind wave short-period swell and weak mid-period swell
will produce breaking wave heights around 5 feet for the northern
coastline of Puerto Rico. Because of this, a High Rip Current Risk
statement is out for the beaches of northwestern Puerto Rico from
Aguadilla to Hatillo, meanwhile there will be a moderate risk for
mostly all other beaches of Puerto Rico and the USVI. Expect
bigger breaking waves this weekend into next week as marine
conditions deteriorate.


.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk until 6 AM AST early this morning for
PRZ001-002-005.

High Rip Current Risk through this afternoon for PRZ008.

VI...None.
AM...None.

&&

$$

SHORT TERM...WS
LONG TERM....RC

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
539 AM AST Fri Jan 27 2023

.SYNOPSIS...
A shearline is causing scattered showers to pass across the
northern sections of Puerto Rico and the northern USVI this
morning. A pattern of shallow passing showers is expected to
continue the next several days as a developing ridge in western
Atlantic enhances northeast winds. Marine and coastal conditions
are deteriorating due to building short-period northeasterly swell
as winds strengthen over the weekend. See the marine sections
below for more details.

&&

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

A shearline has arrived in the forecast area and is expected to
continue past the forecast area by 28/00Z on a southwest course.
There is also another cold front in the western Atlantic that is
squeezing out a high pressure between the front and a low in the
central Atlantic. The high pressure behind the front will continue
to enhance the northeast winds that will increase during the day
and increase over the area through Sunday morning. This is due to
a low pressure currently at 25 north and 40 west that is sending a
shallow layer of moist air toward the forecast area as the low
moves to the west. Currently the GFS shows the axis of the trough
becoming nearly north-south at 29/09Z Sunday at 47 degrees west
longitude. Although some drier air may pass through this afternoon
and evening numerous small shallow showers are expected to be
carried through the area on this northeast flow through Sunday.
The greatest rainfall (up to one half inch through Sunday) is
expected to be in northeast Puerto Rico and along the north coast.


Mid and upper levels, under the influence of a high pressure in
the western Caribbean, are monolithically dry with little moisture
even in the upper levels as an upper level ridge to the west
maintains west to northwesterly flow of 10 to 25 knots.

&&

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

A high pressure system building in the western Atlantic will
maintain a breezy east-northeast to northeasterly flow embedded
with patchy moisture that will cause a regime of scattered showers
along northern and eastern Puerto Rico and over the USVI. Due to
a ridge across the mid-levels of the Caribbean Basin, dry air is
dominating above 700mb which will limit any noticeable vertical
lifting. This pattern will slightly change on Thursday when
another high in the western Atlantic migrates eastward north of
the region, returning surface winds back to an easterly flow. A
perturbation in the trades may arrive on Friday, slightly
increasing shower activity. After this, the positioning of high
pressure to the northeast squeezed between two areas of low
pressure will promote an east-southeast surface wind flow
starting late Friday into the weekend. Southeastern Puerto Rico
will begin to receive an increase in rainfall during this time.

All shower activity is expected to be mild with minimal rainfall
accumulations. Consecutive showers over urban areas may produce
ponding of water but this is not forecast to be much a concern.
With northeast winds during the first half of the long term,
temperatures will be slightly lower than usual as relatively
cooler air advects into the region. Afterwards, the arrival of
easterly flow will return temperatures back to seasonal normal
values.

&&

.AVIATION...SHRA--mostly light--accompanying a decaying shearline
are bringing lcl MVFR conds and mtn obscurations to the nrn and
ern portions of PR. Some SHRA arnd the USVI. Some improvement btwn
27/18- 22Z, but SHRA to return to the north coast of PR
afterwards. Sfc winds vrb less than 7 kts bcmg NE 10-18 kts with
hir gusts btwn 27/12-14Z. Maximum winds N 50-60 kt btwn FL490-540
and NNE-NE 20-35 kt btwn FL110-360.

&&

.MARINE...The arrival of a short-period northeast swell is raising
sea heights in the local Atlantic Waters up to around 7 feet,
causing the issuance of a Small Craft Advisory for the Offshore
Atlantic Waters for Today until further notice. Meanwhile small
craft operators across other marine zones should exercise caution.
Ongoing moderate to strong northeasterly winds are the cause of
this event and they are expected to strengthen over the weekend as
an area of high pressure builds in the western Atlantic.
Therefore, marine and coastal conditions are in a deteriorating
trend.

Beachgoers should be aware that there is a a High Rip Current
Risk Statement out for the northern beaches of Puerto Rico and the
USVI, which includes the northern coastline from Aguadilla to
Fajardo, and the islands of Culebra, St. Thomas, and St. John. The
risk is moderate else where besides southern Puerto Rico, which
has a low risk.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk from this evening through late tonight for
PRZ001-002.

High Rip Current Risk through late tonight for PRZ005-008.

High Rip Current Risk through this afternoon for PRZ012.

VI...High Rip Current Risk through this afternoon for VIZ001.

AM...Small Craft Advisory until 6 PM AST Tuesday for AMZ710.

&&

$$

SHORT TERM...RC
LONG TERM....WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
432 AM AST Sat Jan 28 2023

.SYNOPSIS...A pattern of variable weather conditions is expected
to continue for the next few days. Passing showers embedded with
the trades and dry air will continue to affect the islands
occasionally. Afternoon convection over the western portions of
Puerto Rico is possible, with minimal impacts over the area. Normal
to below normal temperatures are expected to continue in general
due to the mean northeasterly wind flow.

&&

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

The region will remain under the influence of a ridge over the
southwestern Atlantic and a low pressure over the central Atlantic,
both features are reflected at all levels. This will promote promote
moderate to locally fresh northeast winds across the northeastern
Caribbean through the short term period. Trade wind showers embedded in
this flow with areas of drier air in between, will stream over the
islands from time to time. Favoring an advective pattern across the
USVI and across the northern and eastern sections of PR during the
night and morning hours. Some showers could move further inland due to
their fast-moving nature. Latest global model guidance suggest peaks of
precipitable water content close to 1.30 inches this morning, tonight,
Monday morning, and a slightly higher peak of near 1.40 inches by Sunday
night. Overall, minor rainfall accumulations are expected each day.
However, between three quarters of an inch to an inch of rain is
possible in portions of northeastern PR through the period.

Normal to below normal temperatures are expected to continue in general
due to the mean northeasterly wind flow. The main threat will be the
choppy to hazardous seas across most of the local waters, and life-
threatening rip currents along the north and east facing beaches of the
islands. There is a slight threat for ponding of water in roads and
poor drainage areas across northeastern PR through Sunday night.


&&

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

A surface high pressure building in the western to central Atlantic
will maintain east to northeasterly winds across the local area.
This pattern is expected to bring patchy moisture to support the
development of passing showers across the eastern portions of
Puerto Rico and the US Virgin Islands. Scattered showers, although
limited, are forecasted to develop across the western and
southwestern municipalities of Puerto Rico. A mass of drier air is
expected to prevail across the islands. Therefore, shower
activity across the islands will not be significant for the first
half of the long period. The Precipitable Water content (PWAT)
between 1.02 to 1.39 inches indicates a period of low chances of
precipitation, and dry conditions are forecasted for most of the
workweek. By late Thursday into early Friday, a perturbation
moving with the trades will result in a slight increase in shower
activity, mainly for the eastern and northern portions of Puerto
Rico, including Vieques, Culebra and the US Virgin islands.
Continuous showers could lead to minor ponding of water in roads
and poor drainage areas. Temperatures across the islands are
expected to be lower than normal due to the northeast winds.
Expect cooler temperatures, especially over the Central Cordillera
during the overnight hours.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. However, quick passing trade wind
showers could move at times across the USVI terminals, and TJSJ/TJBQ.
Causing mostly -RA/VCSH and SCT/BKN cigs btw FL035-FL065. Low-level
winds will continue from the NE at 15-25 kt.


&&

.MARINE....Moderate to locally fresh east-northeast winds will
maintain hazardous marine conditions, mainly across the Atlantic
waters, Anegada Passage and Mona Passage, where Small Craft
Advisories are in effect. By tomorrow, most of the local waters
will be under Advisories. Choppy seas up to 6 feet and
northeasterly winds up to 20 knots with gusts up to 30 knots
suggest that Small Craft should exercise caution across the rest
of the local waters. For beachgoers, a high risk of rip currents
remains in effect for most north-facing beaches of Puerto Rico and
Culebra, where life- threatening rip currents are likely. Later
today, Saint Croix will be under the high risk.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Monday afternoon for PRZ001-002-
005-008-012.

VI...High Rip Current Risk from Sunday morning through Monday
afternoon for VIZ001.

High Rip Current Risk from this evening through Monday afternoon
for VIZ002.

AM...Small Craft Advisory until 8 PM AST Monday for AMZ710.

Small Craft Advisory from 8 AM this morning to 8 PM AST Monday
for AMZ712-715-722.

Small Craft Advisory from 2 AM Sunday to 8 PM AST Monday for
AMZ732-742.

Small Craft Advisory from 8 PM this evening to 8 PM AST Monday
for AMZ741.

&&

$$

DSR/GRS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
345 AM AST Sun Jan 29 2023

.SYNOPSIS...Variable weather conditions are expected to prevail
for the next few days across Puerto Rico and the US Virgin
Islands. Patches of low-level moisture will continue to affect
the local area and supporting the development of showers across
the islands. With the heaviest showers, ponding of water in roads
and poor drainage areas are possible. Across the local waters,
choppy to hazardous seas continue. Several Small Craft Advisories
and rip current statements are also in effect (Please refer to the
marine section and local products).


&&

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

No significant change from previous discussions. The main hazards
will be the choppy to hazardous seas across most of the waters, and
life-threatening rip currents along the north and east facing
beaches of the islands through midweek. Otherwise, there is a slight
threat for ponding of water in roads and poor drainage areas. Normal
to below normal temperatures are expected to continue in general due
to the mean northeasterly wind flow.

The islands will remain under the influence of a broad mid-to upper-
level ridge centered over Cuba and Florida, and a TUTT low over the
central Atlantic. This will continue to promote drier air aloft and
overall stable conditions. Meanwhile at the surface, a high pressure
is building off the US East Coast, behind a front that lies from the
Bahamas into the north central Atlantic, while a small low pressure
area is reflected from the TUTT a few hundred miles to the southeast
of the front. These surface features will promote patches of low-
level moisture with areas of drier air in between under a moderate
to fresh northeasterly wind flow. This cooler air moving over warmer
waters near the islands will promote an advective pattern, with
showers developing and moving from time to time across the USVI and
across the north and eastern sections of PR. In addition, due to the
stronger than normal trades, showers are expected to move further
inland. Sea breeze variations in southwest PR and local effects
could trigger light afternoon showers today.

&&

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

A building high pressure over the central Atlantic will continue
to dominate the local weather conditions. Moderate to fresh east
to northeasterly winds across the local islands are expect and
will carry patches of low-level moisture to support the
development of shallow showers across the northern and eastern
portions of Puerto Rico and the US Virgin Islands. The latest
Precipitable Water content (PWAT) between 0.90 and 1.30 inches
suggest patches of drier air will be also present. This pattern
will inhibit strong convection across portions of the islands, but
variable weather conditions with groups of clouds, showers and
sun will be observed. By the second half of the long term period a
perturbation is forecast to move across the area that may result
in a slight increase in shower activity, mainly for the eastern
and northern portions of Puerto Rico, including Vieques, Culebra
and the US Virgin islands. Continuous showers could lead to minor
ponding of water in roads and poor drainage areas. Due to the NE
wind flow, temperatures are expected to be normal to slightly
lower than normal. Expect pleasant temperatures across the
islands, especially over the central interior of Puerto Rico.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. However, quick passing wind
showers could move at times across TJSJ/TJBQ and the USVI terminals.
Causing mostly -RA/VCSH and SCT/BKN cigs btw FL035-FL065. Low-level
winds will continue from the ENE at 10-18 kt with higher gusts.


&&

.MARINE...Moderate to fresh east to northeast winds will maintain
hazardous marine conditions across most of the local waters and
passages where Small Craft Advisories are in effect. Choppy seas
up to 6 to 7 feet and northeasterly winds up to 20 knots with
gusts up to 30 knots suggest that Small Craft should exercise
caution across the rest of the local waters. For beachgoers, a
high risk of rip currents remains in effect for most north-facing
beaches of Puerto Rico, Culebra, Saint Thomas and Saint Croix
where life-threatening rip currents are likely.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Tuesday night for PRZ001-002-
005-008-012.

VI...High Rip Current Risk through late Tuesday night for VIZ002.

High Rip Current Risk from Monday morning through late Monday
night for VIZ001.

AM...Small Craft Advisory until 8 AM AST Wednesday for AMZ710-712.

Small Craft Advisory until 2 AM AST Tuesday for AMZ715-722.

Small Craft Advisory from 8 AM this morning to 2 AM AST Tuesday
for AMZ732-741-742.

&&

$$

DSR/GRS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
435 AM AST Mon Jan 30 2023

.SYNOPSIS... Variable weather conditions will continue to persist
across the local area for the next several days. Periods of
sunshine and passing showers will continue to be observed from
time to time, mainly over the northern and eastern portions of
Puerto Rico and the US Virgin Islands. Choppy to hazardous seas
continue across the local nearshore and offshore waters.
Therefore, Small Craft Advisories are in effect for most of the
marine zones. There is a high risk of rip currents along the north
and east facing beaches of Puerto Rico, Saint Thomas, Saint John
and Saint Croix.

&&

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

Choppy to hazardous seas across the Atlantic waters and Passages,
and life-threatening rip currents along the north and east facing
beaches of the islands will continue to be the main threats through
the short term period. Today's showers may cause ponding of water in
roads and poor drainage areas across northeastern PR. Normal to
below normal daytime temperatures are expected to continue in
general due to the mean northeasterly wind flow.

A broad mid-to upper-level ridge centered over Cuba will be the
dominant weather feature through midweek. This will continue to
promote drier air and stable conditions aloft. The trade wind cap
will continue to push fragmented low-level moisture and low-level
clouds at times across the region. This northerly cooler air moving
over warmer waters near the islands will promote an advective
pattern, with showers developing and moving from time to time across
the USVI and across the north and eastern sections of PR. In
addition, due to the stronger than normal trades, showers are
expected to move further inland over central PR. However, minor
rainfall accumulations are expected with this activity. Light
afternoon showers may develop over SW PR if the sea breeze can
overcome the mean northeasterly wind flow.

&&

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

The current forecast continues on track. A surface high pressure
located in the western to central Atlantic is forecasted to be the
dominant feature across the local area. Local weather is expected
to be variable with patches of moisture dragged by the trade
winds. These patches will support shower activity across the
northern, northeastern and eastern Puerto Rico at times and as
well the US Virgin Islands. The general wind flow will continue
from the east to northeast, supporting afternoon convection across
the western portions of Puerto Rico with showers that could lead
to ponding of water in roads and poor drainage areas. By the
second half of the long term period, a small perturbation coming
from the east will increase the potential for more showers across
the local area. A slight change on the wind flow from the east to
southeast will bring more humidity, increasing the frequency of
showers towards the central interior and northwestern portions of
Puerto Rico. The Precipitable Water content values between 1.35 to
1.62 inches indicates a humid a wetter pattern for the end of the
period. Temperatures across the islands are expected to be lower
than normal due to the northeast winds. Expect cooler
temperatures, especially over the mountains during the overnight
hours.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. However, quick passing showers
may cause brief MVFR cigs at the USVI terminals btw 12z-20z, and in
TJSJ btw 20z-23z. Low-level winds will continue from the ENE at 12-
18 kt with stronger gusts.

&&

.MARINE...Moderate to locally fresh northeast winds up to 20
knots with higher gusts, and small northeasterly swell will
maintain hazardous marine conditions across most local waters. Small
Craft Advisories remain in effect for the nearshore and offshore
Atlantic waters, offshore Caribbean waters, Anegada and Mona
Passages, and the coastal waters of northwestern Puerto Rico.
For the rest of the waters, small craft operators should continue
to exercise caution due to choppy marine conditions, with wind-
driven seas of up to 6 feet. For beachgoers, a high risk of rip
currents remains in effect for most north-and east-facing beaches
of Puerto Rico, Culebra, and all the US Virgin Islands, where
life-threatening rip currents are likely.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Tuesday night for PRZ001-002-
005-008-012.

VI...High Rip Current Risk through late Tuesday night for VIZ002.

High Rip Current Risk through late tonight for VIZ001.

AM...Small Craft Advisory until 8 AM AST Wednesday for AMZ710-712-715-
741.

Small Craft Advisory until 2 PM AST Tuesday for AMZ722.

Small Craft Advisory until 2 AM AST Tuesday for AMZ732-742.

&&

$$

DSR/GRS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
521 AM AST Tue Jan 31 2023

.SYNOPSIS...Moderate to fresh northeast trades due to a surface
high over the western Atlantic will continue to promote breezy
conditions and choppy to hazardous wind-driven seas for the next
few days. Life-threatening rip currents will persists across the
north and east facing beaches of the islands through midweek.
Passing trade wind showers will prevail through the end of the
week, with minor rainfall accumulations in general.


&&

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

Variable weather conditions are expected today across the islands,
mainly across the northern and eastern portions of Puerto Rico, and
the USVI in the morning hours. The main hazards across the islands
continue to be choppy to hazardous seas across the Atlantic waters
and Passages until the end of the period. In addition, life-
threatening rip currents will continue along the north and east
facing beaches of the islands until the end of the workweek. For
today, the shower activity should be less than the previous days due
to dry air present across the local area. This weather pattern will
persist for the next few days. A broad mid level high pressure will
be the dominant weather feature and is expected to continue
promoting drier air across the region. For the rest of the period,
fragments of moisture will be carried by the trades, resulting in
passing showers overnight and during early morning hours across the
windward portions of the islands. During the afternoon hours,
convection still possible to occur across the western to
southwestern portions of Puerto Rico leaving minor rainfall
accumulations. Temperatures across the islands are expected to be
normal to below due to the northeast winds.

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

A weak surface high pressure over the central Atlantic will be
replaced by a stronger high pressure on Sunday. In response,
winds will shift from the east to east-southeast and become
moderate to fresh once again later in the weekend. At upper
levels, a ridge west of the region is expected to shift east of
the Leewards by Sunday, as a long wave trough moves slowly
eastwards from the west through the rest of the long term period.
The 500 mb temperature is forecast to drop to around -10 degrees
Celsius during this period, increasing instability aloft.

From Sunday through Tuesday, weak trade wind perturbations will
stream across the islands during the morning hours, increasing
shower activity in early morning convection between the USVI and
eastern PR, followed by afternoon showers over western PR.
Rainfall amounts are expected to remain under an inch, but will
continue to monitor and adjust the forecast as needed during the
next couple of days.


&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hrs. Fast moving trade wind showers may
cause brief MVFR cigs at TJSJ/TIST/TISX btw 10z-22z. Winds will
continue from the NE at 10-18 kts with higher gusts after 31/14Z.


&&

.MARINE...Choppy to hazardous seas between 5 and 8 feet will
continue through midweek due to a fading northeasterly swell and
wind-driven seas. NE winds at 15-20 kt with higher gusts will
prevail for the next couple of days, and SCAs are in effect for
most of the local waters.

Across the northwest to northeastern beaches of the islands there
is an elevated risk of rip currents, and a High Rip Current Risk
remains in effect for northern PR, Culebra, and St. Croix. Please
refer to the latest Coastal Hazard Message (CFWSJU) and Surf Zone
Forecast (SRFSJU) for detailed information.


&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Thursday night for PRZ001-002-
005-008.

High Rip Current Risk through Wednesday afternoon for PRZ012.

VI...High Rip Current Risk through Wednesday afternoon for VIZ002.

AM...Small Craft Advisory until 8 PM AST Wednesday for AMZ710-712.

Small Craft Advisory until 2 PM AST Wednesday for AMZ715-741.

Small Craft Advisory until 2 PM AST this afternoon for AMZ722-
732.

Small Craft Advisory until 2 AM AST Wednesday for AMZ742.

&&

$$

SHORT TERM/AVIATION...GRS
LONG TERM/MARINE...DSR