Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST Wed Dec 21 2022

.SYNOPSIS...

A mid-level ridge will promote stable weather conditions. However,
moisture fragments will sometimes result in the arrival of clouds
and showers across the windward sections of Puerto Rico and the
U.S. Virgin Islands. Shallow afternoon convection due to sea
breeze variations will develop each day across the interior and
western portions. A subsiding northeasterly swell will result in
life-threatening rip currents from Rincon to northeast PR,
Culebra, St Thomas, St John, and St Croix. There is high
confidence that another pulse of northeasterly swell will create
hazardous coastal conditions Friday into the weekend.

&&

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

Mid-level ridge persists over the northern Caribbean and will
continue to dominate for the rest of the week. This will keep on
inhibiting deep convective activity across the region throughout the
forecast period. At low-levels, moisture fragments of an old shear
line remain in the vicinity promoting cloudy conditions and light
showers across windward coastal areas. This trend with passing
showers under an east northeast wind flow will hold through the
morning hours affecting mostly the eastern and northern coastal
areas of Puerto Rico and, at times, Vieques, Culebra and the
northern U.S. Virgin Islands. By late morning into early afternoon,
winds will shift more out of the southeast. This will cause
afternoon showers to develop over interior and the northwestern
quadrant of Puerto Rico. These showers will promote at most ponding
of water in roadways and in poor drainage areas.

By late tonight and Thursday, low-level moisture content will
plummet to below normal levels as the remnants of the shear line
moves north and dry air gets advected by the southeast winds over
the CWA. Therefore, mostly sunny skies and fair weather conditions
are forecast during this period. Moisture will pick up again on
Friday, supporting isolated to scattered showers over windward
coastal areas during morning hours and later over northwestern
portions of Puerto Rico. Limited rainfall accumulations, however,
are expected with any shower activity.

&&

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

A climatological weather pattern may persist throughout the long
term, which is a mixture of sunshine/clear skies and clouds with
showers arriving due to occasional patches of moisture.

A short wave trough will weaken the mid-level high pressure and
the trade wind cap over the Northeast Caribbean, allowing moisture
to rise near or above 700 MB Saturday through Sunday. While at
the surface, model guidance suggests the arrival of moisture
fragments each day, generating passing showers due to cold air
advection over warmer waters, especially overnight and early
morning.

A surface high pressure will tighten the local gradient, increasing
local winds Monday through mid-week and increasing the frequency
of the passing showers. There is a low/moderate chance of a cold
front approaching the northeast Caribbean from the northwest
around Thursday.

&&

.AVIATION...
(06Z TAFS)

Mainly VFR conditions expected through the forecast period. However,
brief passing showers may move in and around the USVI terminals and
TJSJ through 21/14z. TJBQ terminal may observe isolated SHRA after
21/17z. Winds will be out of the NE at 5 to 9 knots through 21/14z,
shifting afterwards more ESE at 10 to 14 knots, with stronger gusts
and sea breeze variation.

&&

.MARINE...

The northeasterly swell is slowly subsiding across the Atlantic
Waters and exposed passages and should continue to do so for the
next few days. However, mariners should continue to exercise
caution due to wave heights of up to 6 ft and winds between 15 and
20 knots. Winds remain moderate to locally fresh but will become
more east-southeast throughout the day.

Another long period northeasterly swell will arrive,
deteriorating marine conditions from Friday onwards. There is a
moderate chance to observe fresh to locally strong winds Monday
through the middle of next week.

Latest buoy data from Rincon, San Juan and Vieques indicated seas
near 2-4 feet at 13/14 seconds. This northeasterly swell will
create strong rip currents from Rincon to Northeast PR, Culebra,
St Thomas and St Croix throughout the day.

&&

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

High Rip Current Risk through this afternoon for PRZ010.

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

AM...None.
&&

$$

CVB, CAM

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
410 AM AST Thu Dec 22 2022

.SYNOPSIS...
Issued at 335 AM AST Thu Dec 22 2022

Easterly flow with patchy moisture will continue over the area
through the next 7 days. Surface high pressure will build into the
northeast Atlantic during the week next week and send a back door
front through the area mid-week for continued showery periods.

&&

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

Low pressure at the surface will run rapidly up the east coast of
the United States today and tonight. When this low moves into
eastern Canada on Friday, considerable cold air will pour into the
western Atlantic behind a cold front. This front will stall or
slow considerably as flow out of the western tropical Atlantic
meets it northwest of the local area. Patches of moisture will be
carried in this flow but will not reach much above 8 kft until
Saturday. Above this moist surface layer air is quite dry. On
Saturday some moisture will reach to 10-12 kft and spawn
additional showers. 500 mb temperatures are expected to be their
lowest of the next 7 days (less than minus 9) on Friday morning. A
few thunderstorms may be possible over west northwest Puerto Rico
due to the cooling of the mid levels. One thunderstorms was
observed Wednesday with the 500 mb temperature at minus 7 degrees
C.

At upper levels, a ridge will build to the west of the area and
weaken as it approaches, but flow will be from the northwest
during the period creating a generally stable environment in the
mid and upper levels. With shallow moisture and stable mid and
upper levels, showers are expected to produce minimal rainfall
except in isolated areas where stronger convection can grow this
afternoon in west northwest Puerto Rico.

&&

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

A broad surface high pressure is expected to build and hold over the
central Atlantic through the long term period. This will promote
moderate to locally fresh trades across the region. Embedded in this
flow, patches of low-level moisture will stream across the region
from time to time. At upper levels, a weak upper level low is
forecast to build east of the Leeward Islands. Models suggest that
an associated induced low-level trough could move across the eastern
Caribbean on Sunday, bumping PWAT values to around 1.50 inches and
promoting better chances of showers across the USVI and PR.

Moisture levels overall should remain at normal to below normal
levels on Monday and Tuesday, and no significant rainfall amounts
are expected across the islands. Late in the long term period, the
GFS and ECMWF models suggest that a pre-frontal trough will set-up
across the northeastern Caribbean. Moisture content and instability
is expected to increase, and shower activity should increase in
coverage during the day on Wednesday across all the islands.
Therefore, the threat for urban and small stream flooding will
increase as well. However, the solution is different for the
associated surface front, the GFS is more aggressive with bringing
the front over our area while the ECMWF has the front lingering
around 25N through Friday.

&&

.AVIATION...
(06Z TAFS)
Issued at 335 AM AST Thu Dec 22 2022

Mainly VFR conditions are expected to prevail across all
terminals through the period. Aft 22/19Z SHRA/Isold TSRA psbl WNW
PR til 22/21Z. Sfc winds to bcm E 8-14 kt with sea breeze
influences. Max winds W 65-75 kts btwn FL355-390.

&&

.MARINE...
Issued at 335 AM AST Thu Dec 22 2022

Seas are expected to build up to 7 feet by tonight across the
Atlantic waters due to the arrival of another northerly swell. A
Small Craft Advisory is already in effect for the offshore
Atlantic waters. This swell is expected to peak at 5-7 feet around
15 to 17 seconds on Friday and through the weekend. This will
likely produce high surf conditions along the north-facing beaches
of the islands due to large breaking wave heights. Minor beach
erosion will be possible, as well as life-threatening rip
currents. A high risk of rip currents will continue across many
beaches with northern and eastern exposure of all the islands.
Moderate to locally fresh trades will continue for the next
several days.

&&


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

High Rip Current Risk from this evening through late Sunday
night for PRZ010.

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

AM...Small Craft Advisory from 8 PM this evening to 2 PM AST Monday
for AMZ710.

&&

$$

SHORT TERM/AVIATION...WS
LONG TERM/MARINE....DSR/MRR

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
509 AM AST Fri Dec 23 2022

.SYNOPSIS...A seasonal weather pattern will prevail,
characterized by mixed periods of sunshine and brief passing
showers. An increase in wind speeds will cause an increased
frequency of showers moving inland from the waters during the
weekend. Long-period N-NE swells spreading across the local
Atlantic waters and Caribbean waters will maintain choppy to
hazardous marine conditions for small craft, while generating
life-threatening rip currents and dangerous swimming conditions
for beach enthusiasts through at least early next week.

&&

.SHORT TERM...Today through Christmas Day...

High pressure at the surface in the northwest Atlantic Ocean will
drop down into the northeast central Atlantic waters during the
next 3 days to maintain a ridge of high pressure across the waters
north of the area between 20 and 30 north latitude. This will
cause the east to east-southeasterly winds over the area to
increase to 15 to 20 knots. It will also carry scattered showers
across the area with increasing frequency Saturday and Sunday--
some accentuated by streamers off upstream islands--and keep
temperatures near normal for the season. Moisture from 850-550 mb
will also be increasing somewhat during the period, but this will
still only yield brief periods of relative humidities over 50
percent in that layer. Today at upper levels a high pressure will
ridge northeast over the Dominican Republic and carry a jet of up
to 80 knots over it. The ridge will advance toward the area during
the period, but remain west of us. The jet will continue with the
ridge but only a remnant of its original strength will remain
after today.

Currently drier air is seen moving into the area quite rapidly,
already having entered the U.S. Virgin Islands and removed showers
from the surrounding waters and now crossing into Puerto Rico.
This will diminish rain chances today over those seen yesterday,
but flow will cause these showers to form in essentially the same
areas as yesterday again today.

&&

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

A broad surface high pressure is expected to build and hold over
the central Atlantic through the long term period. This will
promote moderate to locally fresh trades across the region.
Embedded in this flow, patches of low-level moisture will stream
across the region from time to time. This will promote seasonable
weather conditions across Puerto Rico and the U.S. Virgin Islands.
Latest global model solutions suggest that fronts exiting the US
East Coast will remain mainly over open waters. However, by the
second part of the workweek, a building surface high over the
western Atlantic will promote northeasterly winds, and fragmented
clouds or the remnants of old frontal boundaries could reach the
islands by Friday night.

At upper levels, a TUTT low is forecast to build east of the
Leeward Islands by midweek. Models are indicating that an
associated induced low-level trough will cross the islands between
late Tuesday and early Wednesday. Moisture content and
instability are expected to increase, and shower activity should
increase in coverage. Therefore, the threat for urban and small
stream flooding will increase as well.


&&

.AVIATION...Rapidly moving showers should bring very few
interruptions to VFR conds today. LLVL winds of 15-20 knots from
the E-ESE will cause sfc winds to increase to 8-16 kts from
23/14-16Z. Isold SHRA will dvlp ovr NW PR btwn 23/18-21Z. SHRA
will return to the USVI and ern PR aft 23/23Z. Max winds NW 50-60
kt btwn FL370-420. These winds will increase another 10 kt ovr
TJSJ and another 20 kt ovr the Mona Passage today as a jet moves
into the area and decays.


&&

.MARINE...Latest buoy readings at the San Juan buoy indicated
wave heights around 5-6 feet with periods of 12-13 seconds. In
contrast, the offshore 41043 buoy, located about 170 NM NNE of
San Juan, indicated persistent N-NE swells at around 8-10 feet at
18-19 seconds. As these swells spread across the local Atlantic
waters and Caribbean Passages, expect building seas up to 8 feet
with periods of 18-20 seconds, causing large breaking wave action
along the north and east facing beaches of the islands, which will
produce life-threatening rip currents, dangerous swimming
conditions and minor beach erosion. Small Craft Advisories, High
Surf Advisories, and a High Rip Current Risk were extended in
areal coverage and duration for most local waters and surf zone
areas, now through at least Monday afternoon.

Please refer to the latest Coastal Hazard Message (CFWSJU) and
Coastal Waters Forecast (CWFSJU) for detailed information.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Monday afternoon for PRZ001-002-
005-008-010-012-013.

High Surf Advisory through Monday afternoon for PRZ001-002-005-008.

High Surf Advisory through Monday afternoon for PRZ012.

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

High Surf Advisory through Monday afternoon for VIZ001-002.

AM...Small Craft Advisory until 2 PM AST Monday for AMZ710.

Small Craft Advisory until 2 PM AST Monday for AMZ712-715-722-
725-732-741.

&&

$$

SHORT TERM/AVIATION...WS
LONG TERM/MARINE....DSR/ICP
PUBLIC...ICP

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Sat Dec 24 2022

.SYNOPSIS...

Hazardous seas across the local waters will result in dangerous
breaking waves and life-threatening rip currents along the
Atlantic Coastline and north and east-facing beaches of Puerto
Rico and the U.S. Virgin Islands this Christmas Weekend and next
week. Expect the typical weather pattern with trade wind showers
affecting the islands on and off throughout the forecast period
and afternoon convection developing across the leeward sections
due to sea breeze variations.

&&

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

A patch of moisture has pushed into the region from the east, and is
currently over the USVI and eastern Puerto Rico. This has resulted
in an increase in passing shower activity, mostly over the waters. A
few showers have made their way onshore, but overall generally fair
weather has been seen across the islands through the night. Patchy
moisture will continue to affect the region over the next few days,
with precipitable water values in the patches at near-normal values.
This will support a typical pattern dominated by passing shower
activity, mostly during the overnight and morning hours. With
stability aloft, associated with a mid- to upper-level ridge, this
pattern will continue; high rainfall accumulations are unlikely, as
most showers will be brief with light to moderate rainfall.

&&

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

A broad surface high pressure across the Eastern Atlantic will
tighten the local pressure gradient, promoting locally breezy
conditions throughout the work week. While at the upper level, a
TUTT low is forecast to build east of the Leeward Islands midweek
into the weekend. This TUTT will induce a low-level perturbation
that the breezy trades will push toward PR/USVI with a
low/moderate chance of resulting in showery weather Wednesday and
Thursday.

The typical tropical winter weather pattern should prevail through
Friday into the following weekend, meaning a mixture of
sunshine/clear skies and clouds. Showers will form due to cold air
advection over warmer waters each night and early morning. &&

.AVIATION...
(06Z TAFS)

Generally VFR conds next 24 hours for all aerodromes. Passing SHRA
leading to VCSH through 24/13Z for TIST/TISX, with limited impacts
at terminals. Winds pick up after sunrise out of the E, with speeds
to 10 to 15 knots, with sea breeze variations. Winds diminish after
sunset, becoming light overnight.

&&

.MARINE...

A long period northeasterly swell will result in hazardous seas,
dangerous breaking waves and life-threatening rip currents
throughout the weekend across the local waters and most beaches
with northern and eastern exposure of PR and the USVI. This swell
has a period ranging between 16 and 18 seconds and wave heights
between 5 and 8 feet with occasional seas up to 10 feet. Small
craft advisories are in effect for all the local waters, except
for the southern and western coast of Puerto Rico. These
conditions are expected to linger into early next week. However,
increasing trades next week will further deteriorate seas across
the regional waters.

Coastal conditions will continue to be dangerous, with breaking
waves of 10 feet or more for all the northern coasts of the
islands. There is a high rip current risk for the same areas
through Tuesday.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Tuesday afternoon for PRZ001-002-
005-008-010-012-013.

High Surf Advisory until 6 PM AST Monday for PRZ001-002-005-008-
012-013.

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

High Surf Advisory until 6 PM AST Monday for VIZ001-002.

AM...Small Craft Advisory until 2 PM AST Monday for AMZ710-712-715-
722-725-732-741.

&&

$$

CS, CAM

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
220 AM AST Sun Dec 25 2022

.SYNOPSIS...Dominant high pressure ridging at all levels will
maintain an overall stable and seasonal weather conditions across
the region through the rest of the weekend and into the upcoming
workweek. Typical passing trade wind showers will continue to
affect the local waters and passages as well as the north and east
coastal sections of the islands from time to time. Marine
conditions will remain hazardous across much of the local waters
and passages, resulting in dangerous breaking waves and life-
threatening rip currents across the local waters and beaches.

&&

.SHORT TERM...Today through Tuesday... A surface high pressure
located over the eastern Atlantic continues to generate a trade
wind flow out of the east. These winds are expected to strengthen
in the next several days as the pressure gradient tighten. For
today, the low level steering flow will be at 15 to 17 knots, and
20 to 24 knots for Monday and Tuesday. At the upper levels, a
trough is located just east of the Lesser Antilles. Although this
feature is not expected to impact directly the local islands, it
will induce several areas of enhanced moisture that the wind flow
will carry over the region at times. Therefore, for the next
several days, the frequency of showers is expected to increase.
Columnar moisture should remain shallow, although it could tap
into the mid-levels at times, especially on Monday and Tuesday.
Additionally, with the strong winds, the activity is expected to
move quickly, reducing the chances for any significant flooding to
occur, although ponding of water on roadways and low- lying areas
can be anticipated.

For today, Christmas Day, the most recent satellite-derived
precipitable water product shows the first patch moving across the
Caribbean waters, and some of this activity could make it into
eastern and southern Puerto Rico and across the United States Virgin
Islands. On Monday, a stronger patch arrives, with precipitable
water values reaching 1.7 inches (above normal). Finally, on
Tuesday, an induced surface trough will be crossing the region. So
far, this day appears to be more showery than the others, with
eastern Puerto Rico and the Virgin Islands collecting a little more
rain during the period.


&&

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

A broad surface high pressure across the eastern Atlantic will
continue to build and spread across the north central Atlantic
during the period. Consequently this will tighten the local
pressure gradient and in turn promote locally breezy conditions
through the rest of the work week. Meanwhile in the upper levels,
a TUTT low is forecast to sink southwards across the Leeward Islands
into the northeast Caribbean by Wednesday, and linger into the weekend.
This TUTT will become amplified and induce a low- level perturbation
which in turn will be brought across the region in the form of a wind
surge on Wednesday and Thursday. Thereafter the typical season weather
pattern is forecast to prevail and persist for the rest of the
work week and into the weekend.

Dominated by the fairly strong high pressure ridge across the region,
the overall weather pattern will result in a a mix of sunshine and
few passing low level clouds with some isolated to scattered afternoon
showers mainly over the west interior of PR and just downwind of the
USVI during the day. Mostly clear skies and cool overnight temperatures
can be expected over most land areas except for parts of the north
and east coastal areas, where quick passing overnight and early morning
showers can be expected each day with brief gusty winds from time to
time accompanying the shower activity and along the coastal areas.

&&

.AVIATION...Mainly VFR conditions expected. SHRA expected across the Caribbean
waters, and could reach at times TIST/TJPS through 18Z, and could bring
brief periods of reduced VIS and low ceilings. SHRA is then expected
for TJBQ from 18-21Z. Winds will be out of the ESE at 15-17 knots,
with stronger gusts.

&&

.MARINE...Seas are forecast to range between 5 to 10 feet across
the local Atlantic waters and Caribbean passages through early
next week due to a long period north- northeasterly swell. This
swell will help to produce breaking waves between 8 to 13 feet
across the north facing surf zones. Additionally, moderate to
fresh easterly winds will maintain choppy conditions, resulting in
some confused seas in areas affected by the northerly swell.
Therefore, Small Craft Advisories, High Surf Advisories, and High
Risk of Rip Currents will continue to be in effect across the
islands throughout the weekend into early next week.

&&

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

High Surf Advisory until 6 AM AST Tuesday for PRZ001-002-005-008-
012-013.

High Rip Current Risk through Tuesday afternoon for PRZ010.

High Rip Current Risk through late Tuesday night for PRZ013.

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

High Surf Advisory until 6 AM AST Tuesday for VIZ001-002.

High Rip Current Risk through late Tuesday night for VIZ001.

AM...Small Craft Advisory until 2 PM AST Tuesday for AMZ710-712-715-
722-725-732-741.

&&

$$

SHORT TERM...RAM
LONG TERM....ERG
AVIATION...RAM

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
456 AM AST Mon Dec 26 2022

.SYNOPSIS...Brief passing trade wind showers will continue to
affect the eastern forecast area, gradually diminishing in
frequency as we approach the afternoon. During the afternoon,
brief showers can develop mainly over the western interior and
metro area of Puerto Rico. Nevertheless, no significant
accumulation and generally fair weather is expected for most of
the region. Hazardous marine and coastal conditions, including
choppy seas and life-threatening breaking waves and rip currents
will continue to affect the local waters and north-oriented
beaches.

&&

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

For the rest of the morning and today, shallow low level moisture
will continue to stream across the regional waters, with some
affecting portions of the USVI and the north and east coastal areas
of PR from time to time. Brief Mountain top obscurations can be
expected with the passing showers over the east interior along with
areas of patchy fog in the remaining higher mountains and valleys of
PR until the early morning hours. Mostly sunny skies expected during
the rest of the day but some locally induced afternoon showers may
develop mainly over the western portions of PR. Elsewhere, streamer
like clouds and showers are expected to develop downwind of the
islands including around the USVI with a few showers reaching
portions of east and southeast PR.

Mid to upper level ridge is forecast to hold across the region but
will slightly erode Tuesday into Wednesday, as a Tutt east of the
area becomes amplified across the northern Leewards. This will then
bring cooler mid level temperatures to the region and help
destabilize the upper level favoring more enhanced trade wind
showers. In addition, the surface high across the N central Atlantic
will build and spread across the west Atlantic and north of the
region. This will further tighten the local pressure gradient thus
increasing the easterly winds and low level moisture convergence
Tuesday into Wednesday. That said, still expect a trade wind
moisture surge to cross the region late Tuesday into Wednesday with
accompanying breezy to windy conditions and more frequent overnight
and early morning passing showers with better chance for afternoon
convection over the islands Tuesday afternoon through early
Wednesday. Gradually improving but still breezy conditions are
expected later on Wednesday and with lesser afternoon shower
activity. During this time expect the passing morning showers and
afternoon convection to be fast moving and steered by the fairly
strong easterly trades. Rainfall accumulations so far based on the
expected streamer like convection, should range between half and
inch to one inch with the heaviest downpours. This may however lead
to ponding of water on roads and in poor drainage areas, with only
slight chance of minor urban flooding anticipated in isolated areas
so far.

&&

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

From Thursday and through the end of the year 2022, a seasonal
weather pattern is expected to prevail with some cloudiness and
brief passing showers over north and east coastal areas mainly
during the morning hours followed by scattered showers during the
afternoon hours mainly over interior and western Puerto Rico. Cool
overnight and morning temperatures and mostly clear skies can be
expected over most other land areas with patchy fog over interior
Puerto Rico. A mid to upper level ridge will be slightly eroded by a
TUTT east of the region but will still help promote these
conditions, limiting shower development while mostly leaving our
area depending on patches of moisture filtering in for shower
activity. Tightening of the local pressure gradient, mainly due to a
spreading broad surface high pressure across the Atlantic will also
promote locally breezy conditions during most of the long term
period. Current long term model guidance shows patches of drier air,
with precipitable water values of around or less than an inch, and
patches of more humid air, with precipitable water values of around
or more than 1.5 inches, affecting the region on Thursday and
Friday. Moisture will slightly increase for Saturday through the end
of the long term forecast period as model guidance shows
precipitable water over our region staying around and slightly above
1.5 inches. To start next week, and the year 2023, the mid to upper
level ridge will further erode as a TUTT affects our area through
the end of the long term forecast period, this and the slight
increase in moisture will promote a more active variation of the
seasonal weather pattern.

&&

.AVIATION...VFR conds at all terminals thru fcst prd. VCSH psbl at
TJBQ/TJSJ/TJNR/TISX/TIST til 14/12Z. Brief Mtn TOP obscr psbl ovr
Ern interior due to low clds/-RA til 26/11Z. PR Isold-SCT SHRA ovr
the local Atl waters and btw E PR and the USVI. SFC wnds calm to
lgt/vrb but with brief gusts accompanying the passing SHRA. Wnds
bcmg 15-20kts with ocnl hir gusts and some sea breeze variations aft
26/14Z.

&&

.MARINE...Hazardous marine and coastal conditions are expected to
continue due to a long period north-northeasterly swell. Seas are
expected to reach 5-10 feet across the local Atlantic Waters and
Caribbean Passages through early next week. Moderate to fresh
easterly winds will also promote choppy conditions. A Small Craft
Advisory is currently in effect for all waters but the inner
southern and western waters, where small craft should still
exercise caution. Breaking waves of 8-13 feet will affect most
north oriented beaches due to the north-northeasterly swell. A
High Risk of Rip Currents is also in effect for all of these
beaches, as well as the beaches of Aguada and Rincon.


&&

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

High Surf Advisory until 6 AM AST Tuesday for PRZ001-002-005-008-
012-013.

High Rip Current Risk through Tuesday afternoon for PRZ010.

High Rip Current Risk through late Tuesday night for PRZ013.

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

High Surf Advisory until 6 AM AST Tuesday for VIZ001-002.

AM...Small Craft Advisory until 8 PM AST Wednesday for AMZ710-712-715-
722-725-732.

Small Craft Advisory until 2 AM AST Wednesday for AMZ741.

&&

$$

SHORT TERM...RAM
LONG TERM....MRR

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
507 AM AST Tue Dec 27 2022

.SYNOPSIS...

Quick passing showers and breezy east to southeast winds will
continue to affect our area. Showers and/or passing clouds are
expected to move inland and mainly affect sectors of northern and
eastern Puerto Rico and the local islands from time to time.
Afternoon shower development can also affect sectors of western
Puerto Rico. Rainfall accumulations however, are expected to be
minimal. Hazardous marine and coastal conditions persist due to
the now fading but lingering northeasterly swell and fresh to
locally strong winds. Choppy seas and a high risk rip currents are
expected over the local waters and north-oriented beaches,
respectively.

&&

.SHORT TERM...Today through Thursday

Expect a mix of clear skies and passing low level clouds and
occasional showers overnight into the early morning hours. The
shower activity will be mainly over the regional waters but some may
continue to reach the north and east coastal areas of the islands
from time to time. Brief wind gusts between 20-25 kts will remain
possible with the passing shower.

Expect increasing trade winds and low level moisture convergence
today as the anticipated wind surge and band of moisture will stream
across the islands and coastal waters. Portions of the USVI and
mainly the north and east coastal areas of PR will continue to be
affected, however rainfall accumulations are expected to be a quarter
of an inch or less, as the showers should be fast moving steered by
the brisk low level winds. Mostly sunny to partly cloudy skies
expected by late morning into the afternoon but again expect some
locally induced afternoon showers over the western portions of PR.
Streamer like clouds and afternoon showers may also develop over the
east interior and mainly on the west-end and downwind of the USVI,
Vieques and Culebra. Rainfall accumulations are forecast to be
minimal although some showers may be briefly moderate to locally heavy
at times.

Mid to upper level ridge will hold over the area although slightly
eroding today into Wednesday, as the TUTT east of the islands
continued to become amplified across the northern Leewards. This
along with the cooler mid level temperatures will aid in enhancing
the shower activity carried by the easterly trades. The surface high
across the N central Atlantic will continue to spread across the
west Atlantic and north of the region, and consequently further
tighten the local pressure gradient thus increasing the easterly
winds and low level moisture convergence into Wednesday. Expect
breezy to windy conditions and frequent passing clouds with
occasional showers as well as better chance for afternoon and early
morning shower development through early Wednesday. Due to the
expected fast movement of the shower activity each day, rainfall
accumulations are expected to range between half an inch and one
inch with the heaviest downpours in isolated spots particularly over
portions of the east interior, San Juan metro where streamer like
showers will be possible, and over parts of the west sections of PR.
Lesser amounts can be expected elsewhere. Some showers will continue
to cause ponding of water on roads and in poor drainage areas, with
only slight chance of minor urban flooding anticipated in isolated
areas each day. A gradual improvement but still somewhat breezy
conditions are expected late Wednesday and through Thursday with
lesser afternoon shower activity expected.

&&

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

A seasonal weather pattern is expected to prevail through the end of
the year 2022, on Saturday. A mid to upper level ridge will be
gradually eroded by a lingering TUTT east of the region, promoting
gradually increased instability, however, this will leave the
region mostly dependent, in terms of shower activity, on patches
of moisture advecting into it. Cloudiness and brief passing
showers over northern and eastern coastal areas are expected
mainly during the morning hours followed by afternoon showers
mainly over interior and western Puerto Rico, with possible
streamers also affecting the metro area. Tightening of the local
pressure gradient, mainly due to a spreading broad surface high
pressure across the Atlantic will also promote locally breezy
conditions for the rest of the week. This will also promote faster
moving shower activity. Cool overnight and morning temperatures
and mostly clear skies can be expected over most other land areas
along with patchy fog over interior Puerto Rico. Areas of
precipitable water values at or around 1.5 inches will persist for
most of the long term forecast period, keeping moisture during
the period mostly at normal values for this time of the year. The
mid to upper level ridge will continue to erode to start next
week, and the year 2023, as a TUTT approaches and affects our area
through the end of the long term forecast period. This and
precipitable water values staying at or around normal will promote
a more active variation of the seasonal weather pattern.

&&

.AVIATION...VFR conditions will continue thru the fcst prd. However
increasing SHRA fcst for local flying area as a surge on moisture
in the brisk easterly winds will cross the region. Expect SCT-BKN
lyrs nr FL025...FL050 en route btw islands and ovr the regional
waters with Tempo SHRA PSBL at TIST/TISX/TJSJ/TJNR TIL 27/14z.
Brief MVFR due to low clds and SHRA. Psbl wnd gusts btw 20-25kts
with SHRA. Mtn Top obscr also likely with SHRA/Low clds ovr ern
PR. SFC wnds lgt/vrb but briefly hir w/passing showers...then
increasing to 15-18 kts with ocnly hir gusts and enhanced sea
breeze variations aft 27/14z.

&&

.MARINE...Choppy and hazardous marine conditions are expected to
continue due to the now fading but lingering northeasterly swell
and fresh to locally strong east-to-southeast winds. A Small Craft
Advisory continues to be in effect for all waters but the inner
southern and western waters, where small craft should still
exercise caution. A High Risk of Rip Currents continues for the
north oriented beaches from northwest to northeast Puerto Rico,
Culebra, Vieques, St Thomas and St John and the northern and
eastern coast of St Croix.

&&

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

High Rip Current Risk through this afternoon for PRZ010.

High Rip Current Risk through Thursday afternoon for PRZ012.

High Rip Current Risk through late tonight for PRZ013.

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

High Rip Current Risk through Thursday afternoon for VIZ001.

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

Small Craft Advisory until 8 PM AST Wednesday for AMZ712-715-722-
725-732.

Small Craft Advisory until 8 PM AST this evening for AMZ741.

&&

$$

SHORT TERM...RAM
LONG TERM....MRR

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
543 AM AST Wed Dec 28 2022

.SYNOPSIS...

Showers will continue to move across our local waters and inland
during the early morning hours, mainly affecting sectors of the
eastern half of the region. These showers should be brief and fast
moving. Drier air will move in through late in the morning and
the afternoon will promote mostly fair weather with only slight
chance of a passing showers around the San Juan metro during the
afternoon. A seasonal weather pattern is expected during the next
few days. Choppy and hazardous marine conditions, and a high risk
of rip currents for the Atlantic Coastline, are expected to
continue, now mainly due to fresh to locally strong east-
southeast winds.

&&

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

Mid to upper level ridge will hold over the area but slightly erode
today through Friday, as the TUTT east of the islands gradually
becomes amplified across the northern Leewards and a short wave
trough crosses the Atlantic north of the region. This will aid in
enhancing the trade wind showers east of the region as they make
their way across the forecast area. Meanwhile the broad surface high
pressure spread across the west and central Atlantic will maintain a
fairly tight local pressure gradient resulting in moderate to
locally strong easterly winds. The brisk low level wind will
continue to transport fragments of low level moisture and passing
showers across the local waters and portions of the islands during
the rest of the early morning hours. These shower will be fast
moving and brief with little rainfall accumulations expected.

By late morning and into the afternoon hours more seasonal weather
conditions are expected with skies becoming mostly sunny to partly
cloudy with again some locally induced afternoon showers limited to
portions of western PR. Fewer streamer-like clouds and showers may
develop over the east interior and mainly downwind of the USVI,
Vieques and Culebra later in the day. Rainfall accumulations are
forecast to be minimal although some brief showers may produce
moderate to locally downpours at times. Expect breezy conditions to
continue today especially along the coastal areas and accompanying
the stronger passing showers. Late afternoon and early evening
showers may also be possible but again no significant accumulations
are anticipated. A gradual improvement and more seasonal and fair
weather condtions are forecast by Thursday with another pulse of low
level moisture and increasing passing showers expected by early
Friday as the moderate trade wind convergence increases while
becoming more northeasterly. However no significant rainfall
accumulations or weather features are expected to affect the region
during the period.
.

&&

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

No significant changes to the long term forecast period. A seasonal
weather pattern continues to be expected to start this period and to
end the year 2022, on Saturday. This will include cloudiness and
brief passing showers over northern and eastern coastal areas mainly
during the overnight and morning hours followed by possible
afternoon showers mainly over interior and western Puerto Rico, with
possible streamer development also affecting the metro area. Cool
overnight and morning temperatures and mostly clear skies can be
expected over most other land areas along with patchy fog over
interior Puerto Rico. A broad surface high pressure across the
Atlantic will remain for most of the forecast period. Locally
breezy conditions experienced during the short term period should
improve on Saturday, model guidance currently does not show winds
increasing again until late Wednesday. A mid- to upper- level
ride will be gradually eroded by a lingering TUTT east of the
region, promoting gradually increased instability. The mid- to
upper- level ridge will continue to erode to start next week, and
the year 2023, as a TUTT approaches and affects our area through
the end of the long term forecast period, on Wednesday. The
forecast area will be mostly dependent, in terms of shower
activity, on patches of moisture advecting into the region. Areas
of precipitable water values below or around 1.5 inches, remnants
of past frontal boundaries, will continue advecting into the
region for most of the long term forecast period, keeping
moisture during the period mostly at or below normal values.

&&

.AVIATION...VFR conditions will continue at all terminals thru the prd.
Periods of SCT ocnl BKN lyrs nr FL025...FL050 with SCT -SHRA/SHRA
will produce brief MVFR conditions at TJSJ/TIST/TISX and en route
btw PR and the nrn Leeward Islands til 28/13Z. Brief Mtn top
obscr psbl ovr E interior sections of PR due to low clds and
passing SHRA til 28/12Z. SFC wnds winds calm to lgt/vrb but
locally hir w/passing SHRA...then bcmg mainly fm E and incr to
15-20 kt with higher gusts aft 28/14z.

&&

.MARINE...Choppy and hazardous marine conditions are expected to
continue, now mainly due to fresh to locally strong east-southeast
winds. Seas will range between 6 and 10 feet, mainly over the
offshore and exposed waters. A Small Craft Advisory continues to
be in effect for all waters but the inner southern and western
waters and the Mona Passage. Although most zones are expected to
be out of Small Craft Advisory criteria by late tonight, mariners
should continue to exercise caution. The offshore Atlantic waters
are expected to continue under the Small Craft Advisory for
possibly the rest of the week. A High Risk of Rip Currents
also continues for the north oriented beaches from Aguadilla to
northeast Puerto Rico, Culebra, Vieques, St Thomas and St John and
the northern and eastern coast of St Croix.

&&

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

High Rip Current Risk through Friday afternoon for PRZ005-008.

High Rip Current Risk through late tonight for PRZ012.

High Rip Current Risk through this afternoon for PRZ013.

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

AM...Small Craft Advisory until 2 PM AST Friday for AMZ710.

Small Craft Advisory until 2 AM AST Thursday for AMZ712-715-722-
725-732.

&&

$$

SHORT TERM...RAM
LONG TERM....MRR

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
512 AM AST Thu Dec 29 2022

.SYNOPSIS...
Another surge of moisture in the brief easterly winds, will
continue to cross the region this morning affecting the coastal
waters while producing showery weather conditions and brief gusty
winds mainly along the north and east sections of Puerto Rico and
the rest of the islands including the U.S. Virgin Islands.
Moderate to locally strong easterly winds will maintain breezy
conditions with winds between 15 to 20 mph and occasionally
higher gusts, especially across the local waters and coastal
sections. Choppy to occasionally rough marine conditions as well
as dangerous surf zone conditions will continue most of the
period. A low concentration of Saharan dust is forecast to arrive
across the area by New Years day but the moderate east to
northeast winds expected across the region should limit it's
overall affect across the area.

&&

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

A similar weather pattern as what we've recently seen is expected to
continue through the end of the short term period (and through the
end of the year 2022). The forecast area will be mostly dependent,
in terms of showers, on patches of moisture advecting into the local
islands. A broad surface high pressure over the west-central
Atlantic, and the tightening of the local pressure gradient that it
is promoting, will cause locally breezy easterly winds over our
region for most of the short term forecast period, before relaxing
by Saturday. These winds will continue to bring fragmented moisture
from past frontal boundaries eastward and into our area. In the mid
to upper levels, a ridge is over our region but it will be slightly
eroded by a TUTT east of the region and a short wave trough north of
the region. This will all result in passing showers affecting our
area, these should be limited, with no significant accumulations,
and fast moving, and cloudiness, mainly during the overnight and
morning hours. During the afternoon hours, mostly sunny to partly
cloudy skies are expected with possible convective development over
the western interior and west of the local islands. Seasonally cool
overnight and morning temperatures will be experienced with possible
patchy fog over areas of the interior. Satellite derived
precipitable water values indicate an area with slightly below to
around 1 inch, below normal values, approaching our area. This will
limit shower activity and promote mainly fair weather conditions
today. An area with more humid air, and precipitable water values of
around 1.5 inches, will reach the area by early Friday, once again
promoting passing showers mainly over the eastern and northern
forecast area. Conditions should improve somewhat by Saturday, as
another patch of dry air filters in, promoting more fair weather
conditions, before another area of more humid air reaches the region
during the evening.

&&

.LONG TERM...Sunday through Thursday...
A seasonal weather pattern is forecast to continued with periods
of passing overnight and early morning trade wind showers
followed by partly cloudy to mostly sunny skies at least Sunday
(New Years day) into the early part of new week. This will
include cloudiness and brief passing showers over northern and
the eastern coastal areas at times followed by possible afternoon
showers mainly over interior and western Puerto Rico, with possible
streamer development also affecting parts of the San Juan metro
area. Seasonally cool overnight and morning temperatures with
mostly clear skies can be expected over most inland areas along
with periods of patchy early morning fog over interior sections
of Puerto Rico.

A broad surface high pressure will build and continue to spread
across the Atlantic north of the region. This will remain the
dominant feature for most of the forecast period. Recent model
guidance continued to suggest a mid- to upper- level ridge will
continue to gradually erode as meandering TUTT east of the
region shifts westward over the forecast area. This will gradually
promote increased instability aloft and aid in enhancing shower
activity mainly over the coastal waters. The TUTT is then expected
retrogress over the region and affect our area through the end of
the forecast period by mid week onwards. Additionally, the approach
of a cold frontal boundary and associated band of moisture will
continue to approach the region as the surface high builds north
of the region resulting in increased moisture convergence and
better potential for more frequent passing showers along with periods
of moderate to locally rains steered by the brisk northeast
winds, which are expected during that time. A return of breezy
conditions can again be expected during that time. However,
although more frequent and showery conditions are forecast for the
latter part of the period, only ponding of water on roads and
minor flooding in poor drainage areas are so far expected with
the shower activity.


&&

.AVIATION...
Mainly VFR conditions are expected for all terminals during the
forecast period. Passing SHRA over the region will result in
possible VCSH for most terminals until around 29/13z. E winds
will increase to 15-20 kts with higher gusts after 29/13z. Winds
locally higher near SHRA with brief Mtn top obscr due to low clds
and -SHRA ovr Ern PR. No other impacts to operations are expected.

&&

.MARINE...
Mariners can expect choppy TO occasionally rough seas due to moderate
to fresh easterly winds. Seas will range between 5 and 8 feet across
the exposed offshore waters and passages. Therefore, Small Craft Advisories
are in effect for most of the local waters, excluding the coastal waters
of western and southern Puerto Rico and the Mona Passage. Small craft
operators should exercise caution elsewhere.

Beachgoers, the risk of rip currents remains high for the beaches
on the Atlantic coastline from Aguadilla to Northeast Puerto Rico,
and St Croix in the U.S Virgin Islands. The is still a moderate
risk of rip current elsewhere.

&&

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

High Rip Current Risk through Friday afternoon for PRZ005-008.

VI...High Rip Current Risk through late tonight for VIZ002.

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

Small Craft Advisory until 8 PM AST this evening for AMZ715-722-
725-732.

&&

$$

SHORT TERM...MRR
LONG TERM....RAM
AVIATION...MRR

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
521 AM AST Fri Dec 30 2022

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

.SYNOPSIS...
Issued at 429 AM AST Fri Dec 30 2022

Passing troughs and high pressure to our north will continue to
drive showers in breezy conditions across the area. Marine
conditions will begin to improve tonight and continue through
Wednesday.

&&

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

No major changes to the short term forecast at this time, a similar
weather pattern is expected to persist through the end of the year
2022 and into Sunday, New Year's Day. At the lower levels, a broad
surface high pressure system will continue spreading across the
Atlantic through the period. Tightening of the pressure gradient by
this system will continue to promote locally breezy easterly winds
over our region through Saturday. At mid levels, a ridge will
remain over our region although slightly eroded by low pressure to
our northeast. At upper levels a TUTT northeast of the region
will retrograde to a position over Puerto Rico by Saturday and
then return to the Windward Islands. The easterly to
northeasterly low level winds will bring fragmented moisture from
past frontal boundaries eastward and into the local islands.

Shower activity, throughout the short term forecast will result
from patches of moisture embedded in the trade winds advecting
into the region. Cloudiness and passing showers will continue to
advect into mostly the eastern half of the forecast area, mainly
during the overnight and morning hours. Although some showers will
be moderate and may be locally strong, overall shower activity
should be limited since moisture is greatly reduced above 4 kft
and even lower above 12 kft. Therefore no significant rainfall
accumulations are expected. Seasonally cool overnight and morning
temperatures will be experienced with possible patchy fog over
areas of the interior. During the afternoon hours, mostly sunny to
partly cloudy skies are expected with some passing showers over
the region and possible convective development over the western
interior and downwind of the local islands.

Satellite derived precipitable water values indicate a surge of
moisture as an area with values of around 1.5 inches--near
normal--approaches the local islands and increases the chances of
passing shower activity. Model guidance suggests this air mass
will be present for most of the day, before relatively drier air
filters in by Saturday, New Year's Eve, somewhat improving
conditions. New Year's Eve will see showers increasing overnight
and by Sunday, another mass of more humid air of around 1.5
inches of precipitable water value will cross the local islands.

&&

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

A weak trough oriented northwest-southeast at 700 mb to our
northeast and another trough oriented northeast-southwest at 500
mb and 250 mb to our northwest will cross Puerto Rico and the U.S.
Virgin Islands simultaneously on Tuesday afternoon forming a
bubble low over the area at mid and upper levels as it does so.
This will enhance low-level moisture behind them and bring slight
cooling Monday through Wednesday as moisture increases. Troughing
at upper levels will continue through Friday night.

At the surface high pressure will form along the coasts of North
and South Carolina behind a cold front that is pushing into high
pressure migrating east toward the Canary Islands. This will cause
surface winds to become more northeasterly and allow passing
showers to impact northeast Puerto Rico more. These showers will
also pass through the northern U.S. Virgin Islands with a little
more vigor. But, as the high pressure builds over the west central
Atlantic, winds will strengthen and become more easterly again
and carry showers and slightly warmer air through the area,
allowing temperatures to recover on Thursday and Friday and better
moisture to barrel through in 15 to 20 knot winds. Although
showers will be fairly frequent, there will be some sun between
and accumulations will generally be light.

&&

.AVIATION...
(06Z TAFS)
Issued at 429 AM AST Fri Dec 30 2022

Mainly VFR conditions are expected for all terminals
during the forecast period. Quick passing showers over the region
will result in possible VCSH for the terminals and may result in
brief MVFR conditions at TJSJ and TIST/TISX. E-ENE winds will
increase to 10-20 kts with higher gusts and locally higher near
showers after 30/13z. No other impacts to operations are expected.

&&

.MARINE...
Issued at 429 AM AST Fri Dec 30 2022

Seas remain hazardous in the local outer waters and the Anegada
Passage as moderate to fresh easterly winds keep waters choppy and
seas in the exposed waters up to 7 feet and occasionally 8 feet.
Seas will begin subsiding tonight and small craft advisory
conditions are expected to come down on Saturday morning.
Conditions will continue to improve through Wednesday. High rip
current risks remain for select northern coasts until early
Saturday morning.

&&

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

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

VI...None.
AM...Small Craft Advisory until 8 AM AST Saturday for AMZ710.

Small Craft Advisory until 2 PM AST this afternoon for AMZ715-
722-725.

&&

$$

SHORT TERM/AVIATION/PUBLIC...MRR
LONG TERM....WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Sat Dec 31 2022

.SYNOPSIS...

Patchy moisture will continue to support shower activity across
the region for the next few days. An isolated thunderstorm cannot
be ruled out for Sunday. Moisture will increase around midweek, as
will instability, which will result in an increase in shower
activity. Additionally, isolated thunderstorms are possible,
particularly late Tuesday into Thursday.

&&

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

High pressure at the surface is over the west central Atlantic at
the same latitude as the Carolinas. It will be moving eastward
fairly rapidly, and by Monday it will be just southeast of the
Azores. This will keep a fairly steady moderate to fresh low-level
flow going from the east through the period. This will carry
areas of moisture through the area. Those areas will be
interspersed with dry patches, but more so today than on Sunday
and Monday, in which moderate moisture will be the rule in the
lower levels. Mid levels will have some moisture during the
period, but, by and large, relative humidities will not exceed 60
percent there.

Again at mid levels, low pressure that was seen weakly over the
western Atlantic on Friday will move east-southeast on Saturday
and begin dropping down toward the Leeward Islands on Sunday.
Current models cause it to dissipate at around 20 degrees north
and 56 degrees west.

At upper levels, low pressure around 32 north and 60 west will
have a trough extending into the Caribbean Sea just northwest of
us, and that trough will cross through Puerto Rico and the U.S.
Virgin Islands on Saturday. The exit region of the jet on its
backside will be over the Anegada passage late Saturday night with
northerly flow of up to 55 knots over the area.

The bottom line is that this pattern translates into scattered
shower activity today, but increasing overnight into Sunday with
another pulse overnight Sunday into Monday. Showers will be
relatively shallow with minor accumulations expected. With 500 mb
temperatures around minus 9 to minus 10 on Sunday, an isolated
thunderstorm cannot be ruled out, but will not be included in the
forecast at this time.

&&

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

On Tuesday, moisture will be pushing into the region from the east.
Meanwhile on Tuesday morning, a mid- to upper-level trough will be
to the north of the islands. This trough will move over the islands,
deepening, and then developing a closed low. Increasing troughing
will be induced in the lower mid-levels while this closed low
develops, with the strongest low at 500 hPa. By Wednesday, the mid-
to upper-level low will be to the west of the region, moving over
Hispaniola by Thursday. The lower-mid-level troughing will weaken
starting on Thursday afternoon into the end of the week. On Friday,
the mid- to upper-level low will pull to the north as it weakens,
leaving some weak troughing in its place, which is expected to
remain generally over Hispaniola into the weekend. With the
influence of these troughs, instability is expected to be enhanced
over the region, especially for Wednesday into Thursday. This is
further indicated with the 500 hPa temperatures; by late on Tuesday,
temperatures at 500 hPa will be around -11 to -13 degrees Celsius,
which is cooler than 2 standard deviations below the seasonal
average. These temperatures are not forecast to increase above -9C
through Saturday, with the coldest 500 hPa temperatures Tuesday
night and Wednesday.

Moisture is expected to be around the high end of the seasonally
normal range through the long term period, with occasional brief
decreases from time to time. This will be more than sufficient to
help sustain shower activity over the region. Combined with the
aforementioned instability, the moist layer is likely to extend well
into the mid-levels, especially around midweek. This moisture is
expected to be sustained via advection and convergence, with model
guidance suggesting the potential for a frontal boundary to approach
the region during the weekend further aiding in providing moisture
convergence. It is worth noting that previous model guidance,
including guidance as recent as the 18Z GFS showed more drying
during the second half of the week. This combines with the
likelihood for changes in timing and location of the frontal
boundary, as well as the lead time, to bring fairly significant
uncertainty to the forecast for the back half of the long term
period, particularly Friday into the weekend. The forecast has
relatively high certainty through midweek, though.

All of this is forecast to combine to bring a wetter pattern to the
region. Tuesday is likely to be fairly typical conditions, if
somewhat more showery. On Wednesday, the steering flow is forecast
to be east-northeast to east, and conditions are expected to be
fairly active. There is the risk for thunderstorms starting Tuesday
night and lasting into Thursday. A modest decrease in activity is
expected each day. Late on Saturday, an increase in activity is
possible, depending on what occurs with that frontal boundary.
Additionally, the steering flow depends greatly on the location of
the frontal boundary for the end of the week, and locations of
shower activity may (and likely will) change in future forecasts.

&&

.AVIATION...
(06Z TAFS)

VFR conditions are expected for all terminals during the forecast
period. Quick passing showers over the region will result in
possible VCSH for the terminals and may result in brief MVFR
conditions. E-ENE winds will increase to 10-20 kts with higher
gusts. Maximum winds NW-NNW 25-35 kt btwn FL 275-375.

&&

.MARINE...

Winds of 12 to 18 knots out of the east to east-northeast are
expected across the waters today, which will maintain some choppy
conditions. Seas of up to 7 feet are expected for the offshore
Atlantic waters, while seas elsewhere will remain 6 feet or less.
For the beachgoers, the rip current risk is moderate for beaches of
the USVI, Vieques, Culebra, and southeastern and northern Puerto
Rico, including Aguada and Rincon.

Though marine and coastal conditions are improved compared to what
we have seen for much of the month, boaters and beachgoers are
encouraged to remain vigilant and exercise caution.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory until 8 AM AST this morning for AMZ710.

&&

$$

SHORT TERM...WS
LONG TERM....CRS
AVIATION...WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
525 AM AST Sun Jan 1 2023

.SYNOPSIS...

Increasing shower activity, mostly in the form of passing showers
during the overnight into morning hours, is expected during the
first part of the week. Around midweek, enhanced moisture and
instability are likely to result in active weather for Wednesday
into Thursday. Showers and isolated thunderstorms are expected
those days.

&&

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

Last night, showers began to clear across most of Puerto Rico's
interior but were still scattered across the local waters. During
the late evening hours there were even a few thunderstorms over the
northeast portion of our local outer Atlantic waters. Just after
midnight smoke enveloped the Greater San Juan and Bayamon
Metropolitan Area sending visibilities down to 3 statute miles in
smoke from the exuberant fireworks celebrations of the New Year so
typical here in Puerto Rico. Winds were nearly calm and the smoke
lingered until rain cleared it out. That rain covered much of the
north coast and some of the southeast coast with up to six tenths of
an inch of rain according to NWS Doppler Radar.

This scenario played out due to a 1028 mb high pressure at the
surface in the central Atlantic that kept moderate to fresh trade
winds across the local area. By Tuesday that high will be north of
the Canary Islands and even a little stronger and winds will have
shifted to the northeast the day before. At 700 mb a weak trough
will move across the area late Monday night followed by some areas
of better moisture.

At mid levels high pressure is over the the western Caribbean with
low pressure near 26 north and 59 west. A short wave coming over the
top of the high will accelerate the low on Monday and send it to the
southeast. The shortwave then continues toward the local area and
causes another low pressure to form over and west of the local area.

At upper levels, low pressure around 32 north and 60 west yesterday
afternoon over western Puerto Rico is now found over Guadeloupe. It
will pull away into the Tropical Atlantic late today and Monday as
another trough strengthens upstream and moves toward the area. This
trough is expected to spawn a low north of Puerto Rico Tuesday
evening.

This pattern will bring increasing showers each night Sunday night
through Tuesday night to northeastern Puerto Rico and northern the
U.S. Virgin Islands with showers developing in the northeast flow
over interior and southwestern Puerto Rico each afternoon. Showers
will be brief and sometimes persistent, but accumulations over the
next 72 hours will be modest with some areas exceeding three
quarters of an inch.

&&

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

On Wednesday, a mid- to upper-level low will be located just west of
the islands, pushing over Hispaniola during the morning. It will
linger there through Thursday, slowly weakening, opening up into a
trough on Friday as it moves northward, then northeastward. The
trough is forecast to be to the north of the islands on Saturday,
after which it will pull away slowly from the region. This feature
will result in increased instability over the area, with the best
dynamics for shower development on Wednesday. Modest decreases in
instability are expected each day beyond that. By Sunday, the moist
layer is likely to only reach into the lower mid-levels. The 500 hPa
temperature also suggests good instability over the area,
particularly on Wednesday and into Thursday, with temperatures that
are significantly cooler than seasonally typical.

Meanwhile, increasing moisture is expected over the region for
Wednesday, with moisture convergence occurring, resulting in
precipitable water values that are likely to be at least on the high
end of normal if not above normal. Thursday into the end of the
week, moisture will gradually decrease, becoming patchier. Still,
precipitable water values are likely to remain at least within
seasonal normals through the end of the week, and likely into early
next week. Model guidance continues to show a frontal boundary
approaching the region from the northwest, which is still
expected to promote some moisture convergence, helping to maintain
good moisture over the region for the latter half of the week.
However, as was anticipated, said guidance has backed off on how
close to the region it will get. As such, the east-southeasterly
wind flow will be maintained, becoming more easterly early next
week. Furthermore, shower activity is also likely to decrease
through the end of the week into early next week as a result of
this, as less moisture is expected over the area, as well as
decreased instability.

Overall, the forecast is thus: Wednesday will be an active weather
day. Showers and isolated thunderstorms are likely across much of
the region. Periods of moderate to heavy rainfall are possible, and
could result in some ponding of water (and the potential for minor
flooding cannot be ruled out at this time). Modest decreases in
shower activity are likely through the end of the week, with a
greater decrease anticipated for early next week.

&&

.AVIATION...
(06Z TAFS)

Overall VFR conditions are expected for all terminals during the
forecast period. Quick passing showers over the region will result
in VCSH for most the terminals and may result in brief MVFR
conditions. There will be some mtn obscurations thru 02/06Z. E-
ENE winds will increase to 10-20 kts with higher gusts--strongest
near the coast. Maximum winds NW-NNW 35-50 kt btwn FL 340-430.

&&

.MARINE...

Winds of around 10 to 20 knots are expected out of the east today,
maintaining some choppy conditions across the waters. Seas of up to
6 feet are expected for the offshore Atlantic waters and Anegada
Passage. There is a moderate risk of rip currents for beaches of the
USVI, Culebra, and northern Puerto Rico.

&&

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

$$

SHORT TERM...WS
LONG TERM....CRS
AVIATION...WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
528 AM AST Mon Jan 2 2023

.SYNOPSIS...
Issued at 439 AM AST Mon Jan 2 2023

A rapidly moving short wave trough at upper levels will increase
the instability in the relatively moist flow over the forecast area
and produce a low over Puerto Rico Wednesday that will bring
better showers and a chance of thunderstorms Tuesday and
Wednesday. High pressure in the Atlantic will maintain the low-
level flow of patchy moisture out of the waters just north of the
tropical Atlantic Thursday through the weekend and beyond. This
will prolong the showery weather of the past few days.

&&

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

Patchy moisture continues to affect the region. Precipitable water
in the 02/00Z sounding was above seasonal normals, with a value
of 1.65 inches. Total Precipitable Water imagery from GOES-16
suggests that there has been a modest decrease in moisture since
then, but, overall, the patch of moisture from yesterday remains
over the region this morning. Behind it is a narrow band of
slightly drier air that will move into the region by late in the
morning. Precipitable water levels in this airmass are around 1.3
to 1.35 inches, which is within seasonal normals. As such, a
decrease in shower activity is expected compared to yesterday, but
there is more than enough moisture to sustain a showery day.
Tomorrow, moisture will gradually increase, particularly after
midday. Meanwhile, a mid- to upper-level trough will be
approaching, slowly, from the north. Because of this, increasing
instability is anticipated. This is reflected in the 500 hPa
temperature, which is forecast to fall from around -8C to -9C in
the morning to -12C by late in the afternoon, which would be
significantly cooler than normal, with the typical range between
around -8C to -6C, and the value for 2 standard deviations below
normal is around -10.5C. The forecast minimum for 500 hPa
temperature occurs Tuesday night into Wednesday, with the GFS
suggesting temperatures of -13C or colder, and the Euro's solution
having around -12C. The upper-level trough is forecast to develop
into a closed low, strengthening over the region then pushing
just west of the islands for Wednesday.

On the whole, the expectation is thus:

Today will bring showery conditions to the region, though less than
were seen yesterday. A gradual increase in showers is then expected
for Tuesday, with a greater increase starting late on Tuesday.
Isolated thunderstorms cannot be entirely ruled out for Tuesday
afternoon, with the potential increasing overnight Tuesday into
Wednesday. Increased moisture and instability will lead to an active
weather day for Wednesday. Showers and isolated thunderstorms are
expected. Periods of moderate to heavy rainfall are expected,
particularly with thunderstorms. This could lead to ponding of water
on roadways and in areas of poor drainage; localized minor flooding
cannot be ruled out.

&&

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

The upper level low bringing instability and a slight chance of
thunderstorms to the area on Wednesday will continue just off the
northwest corner of Puerto Rico on Thursday while pulling
gradually north to be reabsorbed into the flow. A second shortwave
will pass through the area on Saturday.

At the surface high pressure will be found near 32 north 51 west.
High pressure over the southeastern coast of the United States
will move slowly northeast, but maintain a tenuous connection with
the high moving through the eastern Atlantic during the period
helping to block most of the weather that would come down from the
north and hold back fronts associated with the next several vigorous
lows that undergo sudden deepening over the western Atlantic. The
last front will be found across the bahamas and central Cuba
Sunday and sagging south toward Hispaniola early Monday. This
will continue to support the easterly flow that will pull
moisture out of the tropical Atlantic or the sub tropical waters
east northeast or the local area. Said moisture moves across us
and then slows as it recurves cyclonically to become parallel with
the front. With no other significant features this will bring
showers across the area with the patches of moisture in our
typical diurnal pattern favoring the east nights and mornings and
the west and interior sections of the island during the
afternoons. A slight but barely noticeable warming trend will
also result.

&&

.AVIATION...
(06Z TAFS)
Issued at 439 AM AST Mon Jan 2 2023

Generally VFR conds are expected across all aerodromes for the next
24 hours. Passing SHRA over the waters and onshore near
TJSJ/TIST/TISX through 02/14Z are not expected to have operational
impacts at terminals. Afternoon SHRA are expected to focus on
interior and W/SW PR, generally N and W of TJPS. Cannot entirely
rule out brief MVFR for TJPS, however. Winds pick up after sunrise
out of the E/ENE to around 10 to 15 knots, diminishing after sunset
and becoming light overnight.

&&

.MARINE...
Issued at 439 AM AST Mon Jan 2 2023

Wind waves and swell will reach a minimum on Tuesday and then
increase as east northeast winds increase over the area. Seas are
forecast to reach 8 feet in the northeast local outer Atlantic
waters by Thursday afternoon and only begin to subside slowly on
Friday. This will cause small craft advisory conditions in the
local outer Atlantic waters and the Anegada Passage beginning in
some waters as early as Wednesday. There is a slight chance of
thunderstorms over the local waters Tuesday through Thursday.

&&

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

$$

SHORT TERM/AVIATION...CS
LONG TERM....WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
532 AM AST Tue Jan 3 2023


.SYNOPSIS...
Issued at 458 AM AST Tue Jan 3 2023

An upper level trough will generate an upper level low north of
the area on Tuesday that will settle into the area on Wednesday
and remain through later Thursday. Along with some additional
moisture this is expected to enhance the showery weather pattern
across the islands and may even be enough to generate isolated
thunderstorms. Winds and seas will increase through Friday.

&&

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

Moisture lingers over the area, supporting passing shower activity
across the region, particularly over the waters. In the northeast
flow, showers are pushing onshore in northern and eastern Puerto
Rico, as well as a few affecting the USVI, Vieques and Culebra.
Though the Total Precipitable Water imagery from GOES-16 shows that
drier air is moving into the region from the north, particularly
in the mid-levels, based on wind direction from the 00Z sounding
as well as the Vertical Wind Profile product from the TJUA NEXRAD.
To the northeast, however, is more moisture that will make its
way through the area. Overall, moisture will be somewhat decreased
compared to yesterday, though low-level moisture will maintain
some showers, regardless. Meanwhile, there is a mid- to upper-
level trough that is deepening to the north/northeast of the area.
This feature can be inferred from the Air Mass RGB satellite
product, which shows some enhanced convection to the south and
east of the trough. This trough will strengthen, deepening into a
closed low, which will affect the region Wednesday through at
least the end of the short term period. Though the positioning of
the mid- to upper-level low is not expected to be necessarily
"optimal" for instability over the region, instability will
increase, significantly. The 500 hPa temperature supports this
scenario, decreasing starting later today. Both the GFS and the
Euro suggest that the 500 hPa temperature will be on the order of
minus 12C to minus 13C over the region tonight and tomorrow. This
is well below seasonal normals; if these values verify, they
would be among some of the coolest seen in January over the region
in the last 30+ years. All-in-all, above normal levels of
instability are anticipated over the region for tonight into
tomorrow.

Starting tonight, moisture will increase over the region, with
precipitable water values likely to exceed seasonal normals by
tomorrow morning. This moisture will persist through the short-term
period. Active weather is expected for Wednesday, with widespread
showers and isolated thunderstorms likely. Periods of moderate to
heavy rainfall are also anticipated, particularly in thunderstorms.
Instability will decrease tomorrow night into Thursday, while likely
remaining at above normal levels for January. As such, a decrease in
activity is expected for Thursday, but scattered to numerous showers
are still expected for much of the region.

The steering flow remains generally northeasterly today; passing
showers will continue to affect northern and eastern Puerto Rico,
with some of these showers pushing inland towards the middle of the
island. Showers will also affect the nearby islands from time to
time. This afternoon, showers are expected to affect southwestern
Puerto Rico again, while passing showers persist in the east.
Tomorrow's activity will be fairly widespread, but the focus will be
eastern Puerto Rico. Winds gain more of a southerly component in the
mid- to upper-levels, which could push some of the stronger showers
northward. Afternoon convection is also expected for western and
interior portions of Puerto Rico. Periods of moderate to heavy
rainfall are likely in some of the stronger activity, which could
lead to ponding of water on roadways and in areas of poor drainage,
and minor or urban and small stream flooding are possible. Though
Thursday's activity will not be as vigorous, ponding of water is
still likely at times.

&&

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

By Friday an old cold front will bring more and deeper moisture
into the area from the northeast. The front will remain in the
area according to the latest from the GFS through the long term
period with good moisture. Hence the current pattern of night and
morning showers in the east and afternoon showers in the west will
persist--likely beyond the end of the period. The upper level low
will also play a role in the showery pattern that will persist
through the period, as areas of upper level divergence cycle
through the area. That low will retreat north and become
reabsorbed into the trough, but a jet around the southeast side of
the trough will remain relatively close to the forecast area with
some enhancement of instability likely.

&&

.AVIATION...
(06Z TAFS)
Issued at 458 AM AST Tue Jan 3 2023

Generally VFR conds expected next 24 hours. Passing SHRA continue,
affecting waters, USVI, and northern and eastern PR, resulting in
VCSH for TIST/TISX/TJSJ. No operational impacts expected at
terminals, though brief MVFR cannot be entirely ruled out. Showers
this afternoon in SW PR expected to remain S of TJBQ and W of TJPS.
Winds pick up out of the northeast after sunrise, to around 12 to 16
knots, subsiding after sunset, becoming light overnight.

&&

.MARINE...
Issued at 458 AM AST Tue Jan 3 2023

Winds will increase over the area beginning tonight and seas will
respond. Currently seas are expected to be 7 or 8 feet in the
local outer Atlantic waters and the Anegada Passage by Wednesday
afternoon. They are expected to reach their maximum height on
Friday morning and then subside below 7 feet on Friday night. A
small craft advisory will go into effect on Wednesday afternoon.
The extent of the moderate risk of rip currents will expand around
the coastlines of the islands today through Thursday. Then,
Thursday night, Saint Croix is expected to have a high risk of
rip currents.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory from 2 PM Wednesday to 2 AM AST Saturday
for AMZ710.

&&

$$

SHORT TERM/AVIATION...CS
LONG TERM....WS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
520 AM AST Wed Jan 4 2023

.SYNOPSIS...A mid-to upper-level trough will continue to promote
showers and thunderstorms across the region throughout the day,
with instability lingering through Thursday. A weak surface trough
is expected to increase shower activity during the weekend.
Moderate to fresh east to northeast trades will prevail during the
next couple of days. Choppy wind driven seas expected through
Saturday.


&&

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

The mid- to upper-level trough is over the area, though upper-level
low is still somewhat north of the islands. This feature will
strengthen today, shifting southward and then southwestward.
Enhanced instability will persist over the region, and has led to
widespread passing showers and isolated thunderstorms through the
night, though much of the activity overnight remained over the
waters. The 0Z upper air sounding showed that the temperature at 500
hPa had already cooled to -12.1C, down from -7.8C with the previous
observation. Model guidance suggests that the temperature has
remained relatively steady, or possibly decreased further a small
amount, further indicating the instability over the region. Though
the temperature will gradually warm over the next couple of days,
it will stay below climatological normals through the period.

Moisture has also continued to increase, with moisture convergence
over the area. Based on the Total Precipitable Water product from
GOES-16, moisture levels, which were already above seasonal normals,
have continued to increase during the night. Modest decreases in
moisture are possible at times over portions of the region, with the
potential for some much drier patches at times, mostly over the
Caribbean. But, on the whole, moisture levels are expected to hold
relatively steady over most of the region through the short term
period. This also suggests a continuation of showery conditions over
the region. Still, the peak in activity will likely be today, with
decreases through the end of the week.

Periods of moderate to locally heavy rainfall are expected to
accompany the shower activity, especially with the thunderstorms. As
such, locally high rainfall totals are possible; ponding of water on
roadways and in areas of poor drainage is likely, and minor or urban
and small stream flooding are possible, especially in eastern and
northern Puerto Rico. Winds become more easterly later today, with
the flow gaining more of a southerly component aloft by late in the
day. As such, areas of concern with afternoon convection are
western/northwestern and interior Puerto Rico, with some activity
also continuing in the east.

On Thursday, the flood threat will be decreased, but, still, minor
and urban and small stream flooding cannot be entirely ruled out.
Friday is a little less certain, in terms of intensity and shower
coverage, and depends on whether or not the dry patches reach the
islands, as well as how long the mid- to upper-level low linger over
the northern Caribbean. Ponding of water in roadways and in areas of
poor drainage will, at least, likely remain a risk on Friday.

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

The upper-level trough is expected to weaken and move east of the
region by late Saturday night or early Sunday. However, this will
induce a surface trough that is expected to move over the islands
during the weekend. Meanwhile, a cold front is expected to remain
north of the region and a surface high pressure rolls eastward
across the western Atlantic, this will continue to promote east to
northeast trades and favor nighttime/early morning showers across
the USVI and east/northern sections of PR. Enhanced afternoon
convection is possible over western PR due to the proximity of
the upper-level trough.

During the first half of the workweek, winds will turn more east
to southeast, in response to the surface high moving into the
central Atlantic and a surface low moving across the northwestern
Atlantic. Normal to above normal temperatures should return under
southeasterly winds. At upper-levels, a ridge is expected to
build south of the area. The 500 mb temperature should warm a few
degrees compared to the weekend, while the precipitable water
content decreases from around 1.65 inches on Monday to near 1.40
inches on Wednesday.


&&

.AVIATION...Generally VFR conds prevail next 24 hours. Brief MVFR for
TJSJ/TIST/TISX through morning with SHRA or potentially TSRA. Gusty
winds vc SHRA/TSRA. VCTS after 04/17Z for TJBQ/TJPS, thru 04/23Z;
VCTS thru 04/22Z for TJSJ. Could see brief MVFR or worse from
SHRA/TSRA for all terminals, though TJPS has relatively low risk.
Winds E 12 to 18 kts with stronger gusts; stronger gustier winds
poss vc SHRA/TSRA. Winds decrease after sunrise, and SHRA activity
shifts to more over waters, dec risk of deteriorated conditions.


&&

.MARINE...Choppy wind driven seas are expected across the regional
waters during the next several days, with hazardous seas at 7 feet
across the offshore Atlantic waters and the Anegada Passage
through at least late in the workweek. Elsewhere, small craft
should exercise caution due to seas up to 6 feet and/or east winds
up to 20 knots. A moderate risk of rip currents continues for most
beaches of all the islands.


&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory from 2 PM this afternoon to 2 AM AST
Saturday for AMZ710.

Small Craft Advisory from 2 AM Thursday to 2 PM AST Friday for
AMZ722.

&&

$$

SHORT TERM...CS
LONG TERM....DS
AVIATION...CS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
436 AM AST Thu Jan 5 2023


.SYNOPSIS...Unstable weather conditions are forecasted to
continue today across the local area due to a mid-to upper-level
trough. Therefore, showers and isolated thunderstorms are
expected to affect most of the region. Ponding of water is
possible in lower elevations and poor drainage areas. Moderate to
fresh winds will prevail, maintaining choppy to hazardous marine
conditions.

&&

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

Showers and isolated thunderstorms affected much of the eastern and
Atlantic waters through the night. Some of this activity moved over
land areas across the USVI, Vieques, Culebra and eastern PR. Near
three quarters of an inch were observed in Cayey. This activity is
expected to redevelop across the same waters and areas through the
morning hours with periods of moderate to brief heavy rainfall.
This unstable weather pattern will continue today, and possibly into
Friday due to the presence of the mid-to upper-level trough and
associated area of low pressure now extending from the Caribbean
waters south of Hispaniola into the Mona passage. This upper-level
low is expected to deepen today over Hispaniola, then gradually lift
northeastward and fill/weaken across the region by Friday into
Saturday. Therefore, a wetter than normal weather pattern will
prevail through the short term period. Ponding of water in poor
drainage areas, and minor urban and small stream flooding is
possible through at least Friday.

Breezy conditions can be expected across the regional waters and
coastal areas with northern and eastern exposure of the islands, due
to a strong surface high pressure across the central Atlantic.
Choppy wind driven seas will persist for most of the local waters
and passages, and a Small Craft Advisory remains in effect for the
Anegada Passage and the offshore Atlantic waters through Friday
night. Normal to below normal daytime temperatures are possible once
again due to cloud coverage and the breezy trades.

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

A weakening upper-level trough is forecasted to move east of the
local area by early Sunday. A surface high pressure continues to
dominate over the central Atlantic, this will promote east to
northeast trade winds and favor more shower activity across the
islands. This pattern is expected to enhance the development of
nighttime and morning passing showers in the windward portions of
Puerto Rico, and the US Virgin Islands. By late Sunday into Monday,
cold front will place north of the region, and in combination with
the surface high pressure in the Atlantic, a showery weather pattern
is expected to continue. Afternoon convection will be enhanced
across the central interior and western portions of Puerto Rico.
Winds are expected to turn from the east southeast for most of the
long term period. Normal to slightly above temperatures should
return due to the southeasterly wind component. The Precipitable
Water Content (PWAT) values between 1.5 to 1.7 inches indicates
some moisture will be available across the local area to support
shower activity.

&&

.AVIATION...Mainly VFR conds expected through much of the forecast
period. However, SHRA/TSRA expected to continue through tonight
across the local waters, which should cause mainly VCTS and -SHRA at
times across the USVI and PR terminals. Brief MVFR conds and mtn top
obscd over eastern PR cannot be ruled out with this activity. Low-
level winds will continue from the east at 15-25 kt.

&&

.MARINE...Mariners can expect moderate to fresh easterly winds,
maintaining choppy to hazardous marine conditions across most of
the local waters and passages. A Small Craft Advisory is in
effect for the offshore Atlantic Waters through late Friday night
due to winds of 15 to 20 kts with higher gusts and seas of 5 to 7
feet with occasional seas up to 9 ft. For beachgoers there is a
high risk of rip currents for the easternmost point of Saint
Croix. Elsewhere, there is a moderate risk of rip currents.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...High Rip Current Risk through late Friday night for VIZ002.

AM...Small Craft Advisory until 2 AM AST Saturday for AMZ710.

Small Craft Advisory until 2 PM AST Friday for AMZ722.

&&

$$

DSR/GRS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
356 AM AST Fri Jan 6 2023

.SYNOPSIS...
A showery pattern is expected to persist for the next several
days, with periods of passing showers, isolated thunderstorms and
gusty winds. Marine conditions will stay hazardous today and
tonight, but will gradually improve during the weekend.

&&

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

Showers and isolated thunderstorms continued across the Atlantic
waters during the overnight. Once again, showers moved over land
areas across the USVI, Vieques, Culebra and eastern PR. Rainfall
amounts were less than a quarter of an inch. This activity is
expected to redevelop across the Atlantic and Caribbean waters, as
well across the USVI and eastern sections of PR throught the day,
with brief periods of moderate to locally heavy rainfall. The mid-to
to upper-level low will continue to slowly lift north-northeast of
the area, while gradually weakening through Saturday, when it is
expected to merge with a polar trough and move east of the Leeward
Islands by Sunday morning. In response, an induced low-level trough
is expected to cross the region from the east during the weekend.
This pattern will continue to enhance nighttime/early morning showers
across the USVI/Eastern PR, and afternoon convection over all the
islands as well.


&&

.LONG TERM...Monday through Saturday...
Surface high pressure north of the islands will maintain the trade
winds out of the east to southeast early in the workweek. These
winds will continue to drag patches of moisture that will bring
occasional showers for the waters an the eastern half of the
forecast area. As the surface high migrates toward the central
Atlantic, the wind flow will shift from the southeast. In the
meantime, a polar trough will begin to exit the southeastern coast
of the United States. This trough will escort a cold front into
the Central Caribbean. As the system approaches to the local area
by the end of the week, moisture will lift from the tropics as
the wind flow turns southward. So far, the it looks like the front
itself will stay north of the islands, along with the bulk of the
rain. However, enough instability should maintain an enhanced
pattern of showers in the islands through next weekend.

&&


.AVIATION...Mainly VFR conds expected through much of the forecast
period. However, SHRA/TSRA could develop and move in and around the
USVI terminals and TJSJ through the entire forecast period. This may
cause tempo MVFR conds and mtn top obscd over eastern PR. East winds
blo FL100 will continue at 15-25 kt.


&&

.MARINE...
Strong winds are maintaining choppy and hazardous seas, especially
along the offshore Atlantic and the Anegada Passage, where a small
craft advisory persist due to seas up to 7 feet. Marine conditions
will begin to improve late tonight, and seas will drop down to t3
to 6 feet for the next several days.

&&

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

AM...Small Craft Advisory until 2 AM AST Saturday for AMZ710.

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

&&

$$

SHORT TERM...DS
LONG TERM....ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
443 AM AST Sat Jan 7 2023

.SYNOPSIS...
Unsettled weather conditions are expected today, with the
strongest activity developing in the afternoon hours. A wetter
than normal weather pattern will prevail for the next several
days, with an increased frequency of passing showers. Urban and
small stream flooding will be possible with the strongest
activity.

&&

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

An induced surface trough will cross the region from the east today,
increasing shower and isolated thunderstorm activity. A mid-to upper-
level trough will merge with a long wave trough north of the region,
while it continues to stream eastwards across the northeastern
Caribbean into the Atlantic waters. At least through the weekend,
this pattern will support wetter than normal and unstable conditions
across the islands. Expect nighttime and early morning convection to
favor shallow convection between the USVI and eastern sections of
PR, with stronger showers and isolated thunderstorms developing
across much of the eastern interior, and along the Cordillera
Central of PR during the afternoon hours. Therefore, there is an
elevated risk for urban and small stream flooding across these
areas, including the San Juan metro area. Lingering moisture on
Sunday and the proximity of the trough will likely result in another
active day.

A more zonal flow aloft and decreasing PWAT content is expected on
Monday, this will favor a more seasonable weather pattern across the
islands. At the surface, east to southeasterly trades will shift the
focus of afternoon showers over northwestern PR, and streamers
developing downwind of the USVI should cause minor rainfall
accumulations over land areas.

&&

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

A surface high pressure migrating into the eastern Atlantic will
maintain winds out of the southeast early in the workweek. At the
same time, a polar trough will move into the central Atlantic with
a cold front located northeast of the Bahamas. The latest guidance
keep this front farther away than in the previous runs, with
limited effects over the local islands. However, the low pressure
will pull some moisture from the tropics into the area,
maintaining precipitable water values of 1.5 to 1.7 inches, which
is above normal for this early in the year. Therefore, the pattern
of increased passing showers will persist during this period.

By the latter part of the workweek and zooming into the weekend,
the cold front will hang just north of the area, while a surface
high pressure exits the southeastern coast of the United States.
The circulation of the high will make the trade winds shift from
the northeast on Friday and from the east on Saturday. Just behind
the high pressure, another cold front will move into the Atlantic
Ocean, causing the pattern to repeat, with winds shifting from the
southeast and additional moisture being pulled from the tropics
into Puerto Rico and the U.S. Virgin Islands.


&&

.AVIATION...SHRA en route from the Anegada Passage may cause
brief MVFR cigs across the USVI terminals and TJSJ through the
forecast period. Additional SHRA and iso TSRA could develop over the
eastern interior of PR, and move in and around TJSJ btw 16z-22z,
causing tempo MVFR conds. At TJBQ/TJPS, VCSH/VCTS should prevail
with the afternoon convection. Surface winds out of the east at 9-13
kt with sea breeze variations aft 14z. Gusty winds expected near
SHRA.


&&

.MARINE...
Recent observations from the buoys indicate seas of 2 to 4 feet
nearshore and around 6 feet in the offshore Atlantic. Since wave
height has decreased below 7 feet, the small craft advisory was
allowed to expired. Moderate winds will maintain choppy seas of 3
to 6 feet during the next several days, and small craft operators
should continue to exercise caution. There is a moderate rip
current risk for the majority of the local beaches.

&&

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

$$

SHORT TERM...DS
LONG TERM....ERG

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Sun Jan 8 2023

.SYNOPSIS...An induced surface trough across the region will
continue to promote shower and thunderstorm activity over the
islands and local waters today. PWAT content decreases somewhat
early in the week, but returns to normal to above normal levels
during the latter part of the week. Light to moderate trades will
prevail through the workweek.

&&

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

An induced surface trough will continue to affect the local area
today, bringing additional moisture to support more shower activity
and isolated thunderstorms across the islands. Early morning
convection is possible across the US Virgin Islands and the eastern
portions of Puerto Rico. Then, in the afternoon hours the strongest
activity accompanied with isolated thunderstorms will develop across
the Central Cordillera and western Puerto Rico. Therefore, ponding
of water in roads and poor drainage areas, and minor flooding are
possible in the mentioned sectors. During nighttime hours, lingering
moisture will result in passing frequent showers across the windward
portions of the islands. This pattern is forecasted to persist each
night for the next several days. By Monday onwards, the weather
conditions will start to improve. A more seasonal pattern will
return with Precipitable Water content (PWAT) values between 1.50 to
1.60 inches. Passing showers embedded with the trade winds will be
observed across the eastern portions of Puerto Rico and the US
Virgin Islands in the morning hours, followed by the afternoon
convection in the central interior and western portions of PR.
Daytime temperatures will remain in the mid 80s across the coastal
areas, and in the upper 70s to low 80s in the mountains. Overnight,
temperatures will stay in the low to mid 70s across the coastal areas
and in the upper 50s to mid 60s in the mountains.

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

A pre-frontal trough is forecast to develop over Hispaniola by
midweek, as a surface low and associated cold front moves from the
the western Atlantic into the central Atlantic. Meanwhile, a
surface high pressure will move off the east coast of Florida
during the same time, promoting northeasterly winds on Thursday
and early Friday. This scenario should support an advective
pattern during the night/early morning hours across the USVI and
northeastern sections of PR, followed by afternoon showers over
southwestern PR on Thursday, shifting slightly to the
west/northwest on Friday. During the weekend, another surface low
and associated cold front are expected to move over the western
Atlantic, setting up a similar pattern as previous days, however,
southeasterly winds are expected on Saturday as the surface high
strengthens over the central Atlantic. This will shift the focus
of afternoon convection over northwest PR. Latest guidance
suggest that a stronger surface high pressure will build over the
southwestern Atlantic into the northeastern Caribbean by Monday.
Promoting moderate to fresh northeasterly winds, and bring the
remnants of the front across the local area.


&&

.AVIATION...An increase in SHRA is expected over the PR and USVI
terminals through 08/22z and may cause brief MVFR cigs across the
TJSJ/TIST/TISX terminals. Afternoon TSRA/SHRA development will
result in VCSH for TJPS 08/18-22Z and VCTS/VCSH for TJBQ between
08/17Z. Winds are from the E between at 10 kts, increasing to 10-15
kts with higher gusts after 08/14Z.


&&

.MARINE...Seas up to 6 feet are expected today across the offshore
Atlantic waters and up to 4/5 feet across the rest of the coastal
waters. Light to moderate winds will prevail between 10-15 kt.
Winds and seas will continue to gradually improve during the next
several days, with seas ranging in general between 3-5 ft across
the offshore waters, and between 1-4 ft elsewhere. There is a
moderate risk of rip currents for most beaches of the islands.


&&

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

$$

SHORT TERM...GRS
LONG TERM....DS
AVIATION...GRS

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
428 AM AST Mon Jan 9 2023


.SYNOPSIS...Passing showers will continue today across the local
islands. A surface high pressure will continue to promote east to
east-southeast winds between 10 to 15 mph. For the afternoon
hours, expect shower activity across the central interior and
western Puerto Rico. This pattern will persist for the next
several days.

&&

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

Showers embedded in the winds will continue to reach the region,
especially the windward coastal sections in Puerto Rico and the U.S.
Virgin Islands.

Moisture content has eroded overnight, but GOES-East-derived Total
Precipitable Water imagery still indicates near to above-normal
moisture across Puerto Rico and the U.S. Virgin Islands. In
addition, although instability has diminished, model guidance shows
relatively steep lapse rates at low and mid-levels. A surface high
pressure across the Atlantic Ocean will continue to promote east to
east-southeast winds, enhancing low-level convergence across the
eastern third of PR and pushing showers over the USVI throughout the
morning hours. Showers will spread across the interior and western
sections late in the morning into the afternoon. A similar weather
pattern will continue on Tuesday and Wednesday. However, the
proximity of the remnants of an old cold front may induce a pre-
frontal trough near the islands by Tuesday, pooling additional
moisture across the region. Therefore, we could observe more
frequent showers.

.LONG TERM...Thursday through Tuesday...

A surface high pressure moving off the eastern coast of Florida,
will promote northeasterly winds for the first half of the long-term
period. This pattern will continue to support the development of
passing showers across the US Virgin Islands and the eastern
portions of Puerto Rico. Afternoon convection will be also observed
across the central interior and western Puerto Rico each afternoon
until the end of the workweek. Transitioning into the weekend,
unstable conditions are forecasted as a surface low and a frontal
system move over the Western Atlantic. The surface low is expected
to support more shower development across the region. This system
will set up a pattern that will be similar to the rains from the
previous days. Ponding of water in roads an low drainage areas are
possible with the heaviest rains. Latest model guidance suggest
that a stronger surface high pressure will build over the Atlantic
into the northeastern Caribbean by Monday into Tuesday. This will
promote moderate to fresh northeasterly winds, and bring the
remnants of the front across the local area. Precipitable water
content (PWAT) between 1.60-1.73 inches suggest a moist pattern
that will persist the entire weekend and into early next week.

&&

.AVIATION...

VFR conditions will persist through the forecast period, but
-SHRA/SHRA will reach the coastal areas and may sometimes move over
JSJ/IST/ISX. +SHRA/SHRA will develop across the interior and W-PR
between 09/15-22z, producing mountain obscuration, and SHRA may
affect JBQ too. Winds will continue calm to light and VRB through
09/13z, then increasing to around 15 kt with higher gusts in/near
SHRA.

&&

.MARINE...Seas between 4 to 6 feet are expected today across the
offshore Atlantic waters and up to 3 to 5 feet across the rest of
the coastal waters. Light to moderate winds between 10 to 15 kts
will prevail. Seas are expected to continue improving early this
week. There is a moderate risk of rip currents for most beaches
of the islands with exposure to the northeast.



&&

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

$$

SHORT TERM...CAM
LONG TERM....GRS
AVIATION...CAM