Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
438 AM AST Wed Feb 2 2022

.SYNOPSIS...Increasing instability and moisture with each passing
day through the end of the workweek. Mid to upper level troughs
combined with the moisture will cause showers and thunderstorms
across the local islands and waters for the next several days. The
marine conditions will gradually deteriorate in the latter part of
this week as well.

&&

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

Recent model guidance and satellite imagery initialized well and
continued to suggest that a fairly moist and unstable pattern is
forecast for the entire short term period. An upper level polar
trough across the west Atlantic, will be reinforced by a mid level
short wave trough during the period and is to become amplified as it
sinks southwards across the southwest Atlantic. This in turn will
will and eventually shift eastwards across the forecast area
Thursday through Friday. Consequently,unstable conditions aloft
along with increased low level convergence can be expected across
the forecast area, as a strong surface high pressure ridge is to
build and move across the west Atlantic while aiding in pushing the
moisture remnants along a frontal boundary across the region.
Therefore, the potential for enhanced afternoon convection and
isolated thunderstorms will remain possible each afternoon. In
addition, the potential for urban and small stream flooding in
isolated areas will remain moderate to high through the period and
this is including in and around the San Juan area as well as over
parts of the U.S. Virgin Islands especially on Thursday and Friday.

At the surface, a light to moderate east northeast wind flow will
persist and therefore continue to transport fragment of low level
moisture with embedded showers over the regional waters and parts of
the coastal areas during the morning hours. For the rest of today,
mostly scattered to numerous showers are expected but mainly over
the interior and west to northwest sections of Puerto Rico as well
as on the west-end and downwind of the U.S. Virgin Islands where
some scattered showers will be possible. Some of the afternoon
showers and thunderstorms may linger into the late afternoon and
evening hours before moving over the near shore coastal waters.

Increasing moisture and instability expected on Thursday with more
frequent showers and isolated thunderstorm activity is expected over
the regional waters with the approach of the frontal boundary and
upper trough. The latest model guidances suggest that the base of
the of the upper level trough will be over The Hispanola by Thursday
afternoon, and the associated surface trough and low level moisture
convergence zone just northeast and extending across the region.
This pattern of unstable conditions will increase the probability
for enhanced and widespread convection across the islands on
Thursday and through Friday. Thunderstorm activity along with the
enhanced showers and periods of locally heavy rains will remain
likely given the cooler mid level temperatures. Therefore, as
mentioned in previous discussions, the combination of all these
factors will enhance convective development over Puerto Rico and the
U.S. Virgin Islands, resulting in widespread and long-live shower
activity. As a result, the threat for urban flooding and quick rises
in rivers and streams will remain in moderate to high for the entire
period. Daytime temperatures are expected to fluctuated near the
climatological normals between the low 70s to the mid 80s across the
islands...with low temperatures in the upper 50s to low 60s in the
higher elevations and low to mid 70 along the coastal areas.

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

The expected increase in shower activity in the short term period
may linger into the long term period, with perhaps less intensity
and fewer thunderstorms. The available moisture will see a
decrease on Saturday, but will increase once again on Sunday to
above normal levels. This above normal moisture could continue
through the first half of next week. However, the reason why we
may see fewer thunderstorms is because the mid and upper level
troughs will have moved east of the local islands by Sunday, and
then a weak ridge may be in its place by Monday onward. For that
reason, there is only isolated thunderstorms in the forecast until
early Monday, but no thunderstorms in the forecast thereafter. But
there may still be enough shower activity, at least through
Sunday, to cause urban and small stream flooding in some areas,
depending on how much rain affected certain areas in the days
prior.

The temperatures through the weekend are forecast to be near
normal both in daytime highs and overnight lows. But early in the
following workweek, temperatures may increase slightly to a few
degrees above normal.

&&

.AVIATION...VFR conds are fcst at all aerodromes durg prd w/SCT-
BKN cld lyrs nr FL025...FL050...FL080 and wdly SCT SHRA across the
regional waters and en route btw islands. Low clds lyrs and passing
-SHRA/SHRA may affect TJSJ/TIST/TISX til 02/14Z with brief MVFR
psbl and Mtn top obscr psbl ovr Ern PR due to low clds and -SHRA.
Aftn SHRA/Isold TSRA likely to affect interior and northern
Puerto Rico fm 02/17Z-02/23z, with brief MVFR psbl due to SHRA/Isold
TSRA possible at TJBQ/TJSJ/TJMZ. SFC wnd calm to lgt/vrb, bcmg
fm east incr to 10-15 kt aft 02/14Z with sea breeze variations.

&&

.MARINE...Seas up to 6 feet are expected today across the offshore
Atlantic waters, and up to 5 feet elsewhere. Winds will be up to
15 knots today. However, a northerly swell will invade the local
waters and seas will start to become hazardous starting on
Thursday. Therefore there is a Small Craft Advisory that will go
into effect starting on Thursday morning. Winds will also increase
starting on Thursday, up to 20 knots with higher gusts expected.
The risk of rip currents is still high for many of the local
beaches, and even though fewer beaches will have this high risk
after tonight, most of the local beaches will continue having
either a moderate or a high risk of rip currents into the weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 74 80 73 / 50 80 60 50
STT 83 72 82 70 / 30 60 60 70

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Thu Feb 3 2022

.SYNOPSIS...Unstable weather conditions will prevail today.
Thunderstorm development will remain possible across Puerto Rico
through the day.Periods of moderate to heavy rain could trigger
urban and small stream flooding later this afternoon across the
interior, northwest, north-central Puerto Rico. Hazardous and
life-threatening rip currents continue for most of the north-
facing beaches of the islands. A swell is affecting the local
beaches today and Advisories will be in effect starting this
morning.

&&

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

Recent model guidance, satellite imagery and derived precipitable
water product all initialized well and continued to suggest a moist
and unstable environment in place and is forecast for the entire
short term period. An amplifying upper level polar trough across the
west Atlantic, reinforced by a mid level short wave and cooler
temperatures aloft, will continue to deepen and sink southwards
across the region through Friday before gradually lifting east
northeast across the rest of the northeastern Caribbean.
Consequently the unstable conditions aloft along with increased low
level moisture and speed convergence is expected across the forecast
area, as the strong surface high pressure ridge will spread eastward
across the west Atlantic while aiding in pushing the frontal
moisture remnants across the area. That said, the potential for
enhanced early morning shower activity along the north and east
coastal areas will remain high, with the best chance for increased
afternoon convection and isolated thunderstorms the rest of today
and through Friday. The potential for urban and small stream
flooding areas will remain high through the period and this is
including in and around the San Juan area as well as over parts of
the U.S. Virgin Islands especially later in the afternoon and even
overnight and on Friday.

A light to moderate east northeast wind flow will persist. This will
therefore continue to bring fragments of low level moisture with
embedded showers over the regional waters and parts of the coastal
areas during the rest of the morning. Some showers will be in the
form of streamers. These streamer-like showers can be persistent in
the same spot and may lead to ponding of water on roads and in poor
drainage areas. For the rest of today, increasing clouds and shower
development is expected across the islands with scattered to
numerous showers expected by late afternoon and evening hours. The
activity should be mainly focused over the interior, west and
northern half of Puerto Rico, as well as over parts of the west end
and downwind of the U.S. Virgin Islands where scattered showers and
isolated thunderstorm will be possible later in the afternoon. The
afternoon showers and thunderstorm activity may linger into the late
afternoon and evening hours before moving over the near shore
coastal waters.

Increasing moisture pooling and instability aloft will continue
through Friday into early Saturday with the upper trough expected to
fill by late Saturday as it become cutoff and an upper level ridge
builds in from the west. In the meantime, more frequent showers and
isolated thunderstorm activity is expected over the regional waters
between eastern Puerto Rico and the U.s. Virgin Islands due to the
proximity of the frontal boundary and upper trough. This pattern
will continue to increase the probability for enhanced and
widespread convection across the forecast area through at least
Saturday. Thunderstorm activity along with the enhanced showers and
periods of locally heavy rains will remain likely given the cooler
mid level temperatures. As a result, the threat for urban flooding
and quick rises in rivers and streams will remain in moderate to
high for the entire period.

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

A mid and upper level troughs are expected to move east of the local
area by Sunday. However, patches of moisture will continue to linger
throughout the area enhancing the potential for more shower activity.
On Monday, a weak ridge will take place over the islands. Drier air
with patches of moisture will be present across the area for at
least a couple of days. This ridge will promote stable conditions
aloft for most of the long period across the region. This pattern of
will result in passing showers across the local waters moving into
the windward portions of Puerto Rico and the U.S. Virgin Islands
during morning hours. Then, in the afternoon hours the moisture
available will combine with the daytime heating and local effects
causing few isolated showers with rainfall accumulations. The U.S.
Virgin Islands are expected to have mainly fair weather conditions.
A seasonal weather pattern pattern will dominate, and the rainfall
accumulation totals remains low. In terms of temperature, there will
be a chance for some degrees above normal. This pattern will
persist through the end of the long period.

&&

.AVIATION...Prevailing VFR conds are fcst at all aerodromes durg prd w/SCT-BKN
cld lyrs nr FL025...FL050...FL080 with SCT SHRA across the regional
waters and en route btw islands. Isold TSRA ovr Atl waters N of the
islands along a Frontal Boundary. Low clds and passing -SHRA/SHRA
may affect TJSJ/TIST/TISX til 03/14Z with brief MVFR psbl and Mtn
top obscr psbl ovr E PR due to low clds and SHRA. Aftn SHRA/Isold
TSRA likely to affect the interior, east and northern Puerto Rico fm
03/16Z-03/23z. Brief MVFR also psbl at TJBQ/TJSJ/TJMZ due to
SHRA/Isold TSRA at TJBQ/TJSJ/TJMZ. SFC wnd lgt/vrb, bcmg fm E 10-15
kts with sea breeze variation aft 03/14Z.


&&

.MARINE...Seas will start to build up this morning with the
arrival of a northerly swell to the local islands. Dangerous and
life- threatening breaking waves associated with the northeasterly
swell will be present through at least the weekend. For
beachgoers, there is a high risk of rip current in effect for most
of the north-facing beaches of Puerto Rico and the U.S. Virgin
Islands. Seas up to 7 feet are expected, with higher waves with
the progression of the swell.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 74 81 72 / 80 80 80 60
STT 82 71 82 71 / 60 80 80 60

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
534 AM AST Sat Feb 5 2022

.SYNOPSIS...Unsettled weather conditions will prevail once again
over the local area due to the proximity of the frontal boundary.
Thunderstorm development will remain possible across Puerto Rico
through the day. Periods of moderate to heavy rain could trigger
urban and small stream flooding later this afternoon across the
interior, northwest, north-central Puerto Rico. Hazardous and
life- threatening rip currents continue for most of the north-
facing beaches of Puerto Rico and all beaches of Culebra, Vieques
and the USVI. A swell is affecting the local beaches today and a
Small Craft Advisory is in effect for the local waters until
Sunday. Expect minor coastal flooding causing erosion in some
areas during high tide.

&&

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

Surface high pressure north of the region will shift farther
eastward into the central Atlantic today but will be reinforced by a
strong area of high pressure which will exit the eastern seaboard
and cross the northwest Atlantic by early Sunday. This will help to
maintain moderate northeasterly winds across the region, but is
expected to become more easterly by Monday as the ridge shifts into
the north central Atlantic. In doing so, the prevailing winds will
become light to moderate as the local pressure gradient gradually
loosens. In the meantime the frontal boundary and deep layered
moisture field has now shifted east southeast over the northern
Leewards and just southeast of the islands. Also, the mid to upper
level low and associated trough continued to sag southwards across
the region with the base of the trough axis now extending across the
U.S. Virgin Island this morning. This will now place the region in
the cooler and more stable airmass while keeping the deep convection
just east of the area. However, the proximity of the boundary and
the upper level feature will maintain a moist and unsettled weather
pattern at least for the rest of today. This scenario will still
favor the potential for enhanced shower activity and thunderstorm
development over the coastal waters and portions of the islands
during the afternoon hours. Urban and small stream flooding as well
as ponding of water on roads and in poor drainage areas will again
be likely as well as mudslides in areas of steep terrain due to
saturated and loose soil.

For Sunday, a gradual improvement expected as the upper levels
become more stable and drier as a ridge will build across the region
from the west, and low leve moisture continues to erode. However an
advective weather pattern will persist and therefore under the
prevailing east to northeast wind flow , passing showers will
continue during the morning hours followed by locally and diurnally
induced afternoon convection over portions of the islands. Shower
development and thunderstorms activity should be more localized by
then and steered by the prevailing low level trade winds. That said,
minor urban and small stream flooding will be possible only in
isolated areas over Puerto Rico with also ponding of water on roads
and in poor drainage areas over the U.S. Virgin Islands. By Monday a
more seasonal pattern is expected but latest model guidance suggest
sufficient advective moisture will be present for locally and
diurnally induced afternoon shower development mainly in isolated
areas over the islands.

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

For the first two days of the long period, a transitioning weather
pattern is expected. A mid to upper level trough will move of the
local area, and a ridge will establish over the islands by
Wednesday. Bands of moisture will continue to linger throughout
the area enhancing the potential for more shower activity. This
ridge will promote stable conditions aloft for most of the long
term period across the region. This pattern will result in passing
showers across the local waters moving into the windward portions
of Puerto Rico and the U.S. Virgin Islands during morning hours.
Then, in the afternoon hours, the moisture available will combine
with the daytime heating and local effects causing a few isolated
showers with rainfall accumulations. The U.S. Virgin Islands are
expected to have mainly fair weather conditions. A seasonal
weather pattern but with more patches of dry air will dominate,
and the rainfall accumulation totals remains low. Temperatures
above normal are forecasted in some sectors as the ridge takes
place over the local area.


&&

.AVIATION...Prevailing VFR conds at all local terminals durg prd except around
TNCM and TKPK where brief MVFR/Psbl IFR will be possible due to
proximity of frontal boundary and upper level trough. This will
enhance SHRA/TSRA dvlpmnt ovr the northeastern Caribbean. Brief MVFR
psbl for TJSJ/TIST/TISX due to SHRA/ Isold TSRA til 05/12Z, with
Mtn top Obscr ovr eastern interior of PR due to Low SCUD clds/-SHRA
til 05/13Z. VCSH elsewhere. SCT-BKN lyrs nr FL022...FL050... FL080.
BKN-OVC btw FL200-FL250 ovr Nrn Leeward islands. Isold TSRA w/Max
Tops NR FL300 ovr Nrn Leewards. SFC wnds LGT/VRB...bcm 15-20 kts
with ocnl hir gusts aft 05/14Z. Aftn convection likely for interior,
east and west into southwest PR as well as around USVI fm 05/16Z-
05/22Z.


&&

.MARINE...A northeasterly swell will be affecting the local area
through the weekend. Expect hazardous marine conditions with seas
building up to 10 feet. Dangerous and life-threatening breaking
waves associated with the northeasterly swell will be present
along the local waters. For beachgoers, there is a high risk of
rip current in effect for all the north-facing beaches of Puerto
Rico, and all beaches of Culebra, Vieques and the U.S. Virgin
Islands. A Small Craft Advisory remains in effect for most of the
local zones until Sunday evening. Minor coastal flooding is
possible causing coastal erosion in isolated spots during high
tide.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 72 80 73 / 80 70 60 50
STT 80 70 82 72 / 70 60 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
422 AM AST Sun Feb 6 2022

.SYNOPSIS...Moist and unsettled weather conditions will prevail
today. Urban and small stream flooding to localized flash
flooding, rapid rises along rivers, and mudslides near steep areas
remain likely to happen during periods of moderate to heavy
rains. Wind-driven seas along with are northeasterly swell will
maintain Hazardous and life-threatening conditions through early
this week. Minor coastal flooding is possible, causing erosion in
some areas during high tide.

&&

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

The proximity of the frontal boundary and the upper level trough
will maintain a moist and unsettled weather pattern at least for
today. This scenario will still favor the potential for enhanced
shower activity and thunderstorm development over the coastal
waters and portions of the islands during the afternoon hours.
Urban and small stream flooding as well as ponding of water on
roads and in poor drainage areas will again be likely as well as
mudslides in areas of steep terrain due to saturated and loose
soil.

For today, a gradual improvement expected as the upper levels
become more stable and drier as a ridge will build across the
region from the west, and low leve moisture continues to erode.
However an advective weather pattern will persist and therefore
under the prevailing east to northeast wind flow, passing showers
will continue during the morning hours followed by locally and
diurnally induced afternoon convection over portions of the
islands. Shower development and thunderstorms activity should be
more localized by then and steered by the prevailing low level
trade winds. That said, minor urban and small stream flooding will
be possible only in isolated areas over Puerto Rico with also
ponding of water on roads and in poor drainage areas over the U.S.
Virgin Islands. By Monday a more seasonal pattern is expected but
latest model guidance suggest sufficient advective moisture will
be present for locally and diurnally induced afternoon shower
development mainly in isolated areas over the islands. Conditions
are expected to improve by late Monday into Tuesday, as we move
into a more drier weather pattern.

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

A drier weather pattern is expected to prevail through the long
period. Latest model guidance continues to suggest the placement
of a mid level ridge that will establish over the islands by
Wednesday. Bands of moisture will continue to linger throughout
the area enhancing the potential for shower activity. This ridge
will promote stable conditions aloft for most of the long term
period across the region. This pattern will result in passing
showers across the local waters moving into the windward portions
of Puerto Rico and the U.S. Virgin Islands during morning hours.
Then, in the afternoon hours, the moisture available will combine
with the daytime heating and local effects causing a few isolated
showers with rainfall accumulations. The U.S. Virgin Islands are
expected to have mainly fair weather conditions. A seasonal
weather pattern but with more patches of dry air will dominate,
and the rainfall accumulation totals remains low.

&&

.AVIATION...Brief MVFR conds can be expected at times across the
TJSJ, TIST, and TISX,TJBQ terminals durg prd as wdly SCT SHRA/Isold
TSRA moves through the local flying area. SFC winds will remain
easterly around 10 knots with ocnly hir gusts with SHRA/TSRA. SCT-
BKN CIG nr FL025...FL040...FL080...BKN-OVC nr FL250. Mtn top Obscr
ovr ctrl and eastern interior of PR due to Low CIG/SHRA til 06/14Z.
Aftn convection again likely for interior, east and west into
southwest PR as well as the vicinity of USVI fm 96/16z-06/22Z.

&&

.MARINE...A combination of wind-driven seas and a northeasterly
swell will be affecting the local area through the next several
days. Expect hazardous marine conditions with seas building up to
10 feet. Dangerous and life-threatening breaking waves associated
with the northeasterly swell will be present along the local
waters. For beachgoers, there is a high risk of rip current in
effect for all the north-facing beaches of Puerto Rico, and all
beaches of Culebra, Vieques and the U.S. Virgin Islands. A Small
Craft Advisory remains in effect for most of the local zones until
early Monday. Minor coastal flooding is possible causing coastal
erosion in isolated spots during high tide.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 73 82 73 / 70 70 40 20
STT 82 72 82 72 / 60 50 40 30

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
441 AM AST Mon Feb 7 2022

.SYNOPSIS...
An active weather morning will prevail this morning, as additional
heavy showers moves from the waters and stream over the east and
northern sections of Puerto Rico. Weather conditions should
gradually begin to improve today, and a more typical weather
pattern is expected. However, the threat for flooding is still
moderate to high since soils are saturated in these areas.

&&

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

High pressure in the northern Atlantic that left Newfoundland this
morning, will hold a ridge over the western Atlantic. The front from
a low pressure 1500 miles east northeast of the area trails across
the Windward Islands, but more significantly, a zone of convergence
and a weak mid-level trough lies across Puerto Rico and the U.S.
Virgin Islands with a band of moisture and showers that is being
held in place by northeast flow from the high. On Tuesday the band
of moisture will move out of the area, but low level moisture in the
northeast flow will persist through the period and 1000-850 mb
thicknesses will reflect the cool flow out of the the central
Atlantic as well as the cooling effect of the clouds and showers.
The atmosphere will become more stable during the period, hence
thunderstorms are expected today, and during the afternoon tomorrow
over western and interior Puerto Rico, but should not be a problem
on Wednesday.

Owing to the saturation of the soils across the area, rains that
fall over the area will mostly contribute to the threat of flooding
of urban areas and small streams. Mainstem rivers could still flow
out of their banks today in the heavier rains. Conditions are
expected to improve on Tuesday with considerably less rain on
Wednesday. Until most of this water drains there is a good chance
that steeper terrain will experience mudslides.

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

A stable weather pattern will prevail for the long term period. A
mid to upper-level ridge will remain in place, resulting in drier
air aloft and unfavorable conditions for vertical shower
development. In combination with precipitable water values near
the climatological normals, this pattern will result in minimal
shower activity for the region. This does not mean it will be
completely dry, since the usual afternoon shower activity may
still form over the interior and western sections of Puerto Rico
due to the local effects on Thursday. According to the model
guidance, the available moisture will decrease over the region
from Friday into Sunday morning. In general terms, this will
result in very fair weather conditions for most of the weekend,
with minimal shower activity over the area. On Monday, a high
surface pressure located well at the northeast will result in a
more southeasterly wind over the region. The wind flow pattern
will push another patch of moisture into the area. This increase
in moisture will result in shower activity in the morning and
evening hours over eastern sections of the region and the typical
afternoon convection over northwestern Puerto Rico.


&&

.AVIATION...
SHRA with mdt to hvy rain will bring periods of MVFR to TJSJ/TJNR
and Vieques and mtn obscurations over the NE third of PR thru at
least 07/22Z. SHRA with MVFR and mtn obscurations will spread west
ovr PR aft 07/15Z. MVFR conds in SHRA are expected to occur briefly
at TISX til 07/15Z. Brief SHRA and MVFR CIGs psbl TNCM/TKPK. Sfc
winds increasing to 10-20 kts with gusts to 25 kt aft 07/14Z. Max
winds less than 30 kts. Winds E up to FL225 and then N-NE up to


&&

.MARINE...

A fading northeasterly swell combined with a moderate to fresh
wind flow will continue to result in hazardous marine conditions
for most local waters. As a result, the small craft advisories
remain in effect until 2 PM AST this afternoon. After that, seas
will diminish, remaining up to 6 feet across the Atlantic offshore
waters. For the rest of the week, conditions will improve, and
seas up to 5 feet will prevail.

For the beachgoers, hazardous coastal conditions will prevail for
all the north exposed beaches of the local Islands for today. Large
breaking waves of up to 13 feet will also cause dangerous
swimming and surfing conditions, as well as localized beach
erosion. For this reason, a High Surf Advisory is in effect for
beaches at the north coast of Puerto Rico and Culebra until 6 PM
AST this evening. Additionally, A high risk of a rip current is
in effect for all the north coast and east Puerto Rico, including
most of the local beaches at Vieques and Culebra and beaches of
the U.S. Virgin Islands. The high risk is expected to prevail for
most of the workweek across most local beaches.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 73 82 74 / 100 60 60 40
STT 83 72 83 71 / 60 40 40 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
531 AM AST Wed Feb 9 2022

.SYNOPSIS...Variable clouds and a few showers are expected across
the forecast area for the morning hours. Satellite imagery shows
a patch of clouds and moisture moving into the area, enhancing the
few passing showers over eastern Puerto Rico and the U.S. Virgin
Islands. For the rest of the short term period, stable conditions
will prevail with some light overnight showers Thursday and
Friday as a mid level ridge establishes over the region.

&&

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

High pressure in the north central Atlantic, is moving east toward
the Azores. A ridge extends across the Atlantic to the Bahama Islands
and the northeast Caribbean. This ridge will remain anchored there
through the period while fading slightly. At mid levels, high
pressure will remain over or just north of the forecast area. At
upper levels again the axis of a ridge is centered over the area.
Currently fairly dry air is moving southwest toward the forecast
area, although the air at and below 850 mb will remain fairly moist.
A field of stratocumulus are in east northeasterly flow over the
area, but very few showers will be seen until a patch of moisture
moves through late tonight and a long but narrow band of low level
moisture in the easterly flow moves through the area late Thursday
night. Each will trigger more showers, but with only minor
accumulations owing to their relatively shallow nature and the fact
that they are moving at almost 20 knots. And, most of the shower
activity will be over eastern Puerto Rico. This shower activity will
favor the eastern slopes of Puerto Rico but will leave very little
for the southern foothills and plains or the U.S. Virgin Islands.

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

A strong surface high pressure located in the northeast Atlantic
will dominate the local weather pattern for most of the first part
of the long term period. Meanwhile, a lingering upper level
trough will induce several patches of moisture at the low levels,
mainly over the tropical Atlantic. These patches of moisture with
precipitable water values near or slightly above climatology will
reach the local region embedded in the trade wind flow during the
period. As a result, increased shower activity is possible each
day. This pattern of shower activity will be minor and limited due
to a mid level ridge dominating the 500 MB level. Therefore, the
forecast calls for the typical shower activity in the afternoon
hours over the interior and western portions of Puerto Rico. Like
today, Saturday looks to be the driest forecast day as a small
pocket of drier air will filter into the region, turning the
weather conditions more favorable. On Tuesday into Wednesday, both
models guidances (GFS and the ECMWF) suggest a building surface
high pressure will push a pre-frontal boundary to just northeast
of the local region. At the same time, in the upper levels, a
south-sinking polar trough will enhance moisture and instability
aloft. This feature, combined with the low-level moisture, will
increase the showers` intensity and coverage.

&&

.AVIATION...
VFR conditions. Some lcl CIGs of 035-050. Sfc winds east
increasing to 10-18 knots with gusts to 26 knots in sea breezes
psbl. Maximum winds W 30-40 knots btwn FL295-400.

&&

.MARINE...

Across the regional waters, seas will remain choppy up
to 6 feet due to moderate to fresh winds across the local waters
of up to 20 knots. Therefore, small craft operators should
exercise caution across most local waters. No significant changes
are expected to the marine conditions, as windy conditions prevail
over the local region. There is a high risk of rip current for
most of the north exposed beaches of Puerto Rico, Culebra, and the
U.S. Virgin Islands. For the rest of the area, the risk will
remain moderate. Small craft advisory conditions will become
possible by Friday due to seas and an increasing northeasterly
swell.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 84 74 / 20 40 40 50
STT 84 73 83 73 / 20 20 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
519 AM AST Thu Feb 10 2022

.SYNOPSIS...High pressure in the northeastern Atlantic will
maintain moderate to fresh easterly trade winds through Friday of
next week. Periods of showers are expected as bands of moisture
interspersed with drier air move over the region, but moisture in
general increases Wednesday through the following Friday.

&&

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

Clear skies with periods of partly cloudy skies with a few showers
will prevail today across the forecast area. An elongated surface
high pressure over the northeastern Atlantic will continue to
result in easterly winds. A patch of drier air embedded in the
trade wind flow, with precipitable water values below an inch
(GOES-16 PWat) will filter into the area. Additionally, a building
mid level ridge will enhance drier and stable conditions,
causing short-lived shower activity. Nevertheless, afternoon
convection is still forecast for some western sectors of the
island today. On Friday, weather conditions will deteriorate
slightly as a wind surge with precipitable water values near
climatological normals moves into the area, increasing the
coverage and intensity of the shower activity. Although low-level
conditions will be favorable for shower development, the activity
will still be short lived due to the presence of the mid-level
ridge. Therefore, the flood threat should remain low with the
heaviest activity over the interior and western sections of Puerto
Rico. As the wind surge moves out of the region, a drier airmass
will filter in again on Saturday. So far, Saturday looks to be the
driest day of the short term period. Daytime temperatures will
remain between the mid 70s to the mid 80s.

In general terms for the U.S. Virgins Islands, mainly fair weather
conditions will prevail today through Saturday. On Saturday, more
frequent showers will be possible, however, this shower activity
will be fast moving, and the rainfall accumulations should remain
minimal.

.LONG TERM...Sunday through Friday...
High pressure in the north central Atlantic Ocean will move east
while a low pressure off the Virginia coast shoots northeast. High
pressure will build behind the front trailing the low during the
early part of the week and into the western Atlantic. This will
cause the front to be oriented east-west and stall near 25
degrees north latitude and also allow patches of moisture in the
east northeast flow over the local area to gain increasing
moisture during the week. A low pressure forming northeast of the
area on Friday (next week) will begin to shift the flow above the
lowest layers more northerly so that the portion of the front
north of the area can sag into Puerto Rico and the U.S. Virgin
Islands, with the best moisture of the week. Although both the GFS
and the ECMWF agree on this scenario, it is still too far out to
have good confidence as without the low forming, the front will
remain well north of the area.

Shower activity that does form Sunday through Wednesday will be
quite limited due to the very dry air above 10 kft during that
period. Mid-levels will begin to moisten after Wednesday.

A broad upper level ridge will continue in the area until next
Thursday when a weak short wave passes by to the north.

&&

.AVIATION...VFR conditions are expected through the forecast
period. VCSH may be possible this afternoon across TJBQ, but no
significant hazard is expected. Winds will be from the E-NE at
around 15 KT with occasional gusts and sea breeze variations for
the rest of the day. After 10/22Z a wind surge will move over the
area increasing the showers for TKPK, TNCM, TIST,TISX, TJSJ and
TJPS at least until 11/06Z.


&&

.MARINE...Swell from the northeast will increase tonight and
Friday bringing 6 to 7 foot seas to the Atlantic outer waters and
Anegada passage. This and increasing winds later tonight and
Friday will cause Small Craft Advisory conditions to spread
through unprotected waters tonight through Saturday. Seas will
abate somewhat on Saturday and Sunday, but additional wave pulses
will keep seas in the local waters vulnerable to northeast swell
and wind driven waves close to 7 feet until Monday. Swell from the
northwest will bring hazardous seas back to the areas waters on
Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 85 74 / 20 50 50 20
STT 83 73 83 74 / 20 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
536 AM AST Fri Feb 11 2022

.SYNOPSIS...High pressure in the northeastern Atlantic will
continue through early next week. Then a stronger high pressure
will enter the western Atlantic and build Tuesday through
Thursday. This will maintain moderate to fresh easterly trade
winds through Friday of next week. Periods of showers are
expected as bands of moisture interspersed with drier air move
over the region, but moisture in general increases Monday and
Tuesday.

&&

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

A surface high pressure over the northeastern Atlantic Ocean extending
into the tropical Atlantic will continue to result in easterly
winds for most of the short term period. A moisture surge embedded
in the trade winds will move into the region, enhancing trade
wind shower activity over the local waters and windward sections
of the local islands. This activity will remain shallow due to
the presence of the mid level ridge. Additionally, showers will
be fast moving due to a moderate to fresh easterly wind dominating
the local pattern. The moisture surge is a fairly narrow band that
is forecast to leave most of the area by the afternoon hours which
will leave mainly clear to partly cloudy skies. For Saturday into
Sunday, an upper level trough located in the tropical Atlantic
and an associated surface disturbance will promote patches of
shallow moisture. As the surface pressure results in easterly
winds, a mixture of low level moisture with some dry airmass
patches will dominate the local weather. Although low-level
moisture will be enough for some shower development, the activity
will still be short lived due to the presence of the mid-level
ridge. Therefore, the flood threat should remain low with the
heaviest activity over the interior and western sections of Puerto
Rico. Daytime temperatures will remain between the mid 70s to the
mid 80s across the local islands. For the U.S. Virgins Islands, a
few showers might reach the islands today, however rainfall
accumulations will remain insignificant. On Saturday into Sunday,
more frequent patches of moisture are possible. Nevertheless, this
shower activity will be fast moving, and the rainfall
accumulations should remain minimal.

.LONG TERM...Monday through Saturday...

High pressure will be found in the northeastern Atlantic from
where it has been dominating the central Atlantic and extending
into the northeastern Caribbean. A trough offshore from the
eastern United States will develop as it moves northeastward on
Monday. High pressure over the Great Lakes area on Monday will
move into the western Atlantic and build on Wednesday to
reinforce the trade wind flow and the accompanying marine
inversion over the area. Moisture from a westward moving trough in
the tropical Atlantic will enter the area with the trade wind
flow Monday and Tuesday and hold the front trailing the low in the
western Atlantic and its accompanying moisture north of the area
until Friday. A weak low generated by an upper level trough in the
eastern Atlantic will bring northerly flow over Puerto Rico and
the U.S. Virgin Islands on the following weekend that will bring a
second impulse of moisture across the area beginning that
Saturday night.

Although mid levels will be quite dry during the period, some
moisture will intrude into the lower portion of the mid layers
Tuesday through Saturday.

A ridge at upper levels will dominate the weather pattern through
Tuesday, then a shortwave trough is expected to cross through the
area on Thursday.

Patchy low level moisture will still be the primary driver for
shower activity across the area during the long term period, and
despite the varying factors that should enhance the shower
activity across the area mentioned above, weak moisture above 850
mb, a generally strong marine inversion and winds of 15 to 25
knots at 850 mb will generally limit rainfall amounts during the
period. So the result is that few features are generated or able
to remain that can cause more notable weather across the area
beyond the continual passage of wetter and drier parcels carrying
brief passing showers.

&&

.AVIATION...VFR conditions expected through the forecast period.
VCSH and -RA is forecast between 10/09Z to 11/15Z across TKPK, TNCM,
TIST,TISX, and TJSJ but no significant hazards are expected.
Winds will be from the E-NE at around 15 KT with occasional
higher gusts and sea breeze variations for the rest of the day.
After 11/22Z winds are expected to diminish. Maximum winds W-WNW 36-46
knots btwn FL280-335.

&&

.MARINE...Winds will increase and bring hazardous seas to the area
today. A northeast swell of 8 to 9 seconds of between 3-4 feet
will increase across the area also. Small craft advisory
conditions will be down by Monday, but choppy seas of 5 to 6 feet
will continue in most exposed waters until another swell from the
northwest enters the forecast area on Wednesday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 84 74 / 50 20 20 30
STT 83 74 84 73 / 30 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
522 AM AST Sat Feb 12 2022

.SYNOPSIS...A generally stable weather pattern and breezy
conditions will prevail throughout the weekend and the following
workweek. Patches of low-level moisture embedded in the trade
winds will bring isolated to scattered shower activity. Still, the
weakening of the mid-level ridge and enhanced low-level moisture
convergence will support an increase in showers by midweek.
Increasing winds and a small northerly swell will maintain choppy
to hazardous marine and surf zone conditions.


&&

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

Breezy conditions and passing showers prevailed across the region
through the overnight hours. Observed rainfall accumulations were
generally up to a tenth of an inch. Gusty winds between 25-30 mph
were noted with the showers across the U.S. Virgin Islands and
east/northeast sections of Puerto Rico. Showers moved further inland
across portions of central PR due to the stronger than normal
trades. Minimum temperatures were from the low 60s across the higher
elevations to the low 70s across coastal areas.

A mid-to upper level ridge pattern over the region will continue to
promote dry air and stable conditions aloft, as well as support a
strong trade wind cap across the area through the rest of the
weekend. At the surface, fresh to strong easterly trades are
expected to continue through Sunday. The mid-level ridge is forecast
to weaken slightly on Monday as a polar trough moves over the
western Atlantic, and at the same time a TUTT induced trough is
expected to reach area from the east. In response, winds will
decrease somewhat and acquire a northeasterly component. However,
PWAT is still forecast to remain between 0.90-1.30 inches through
the short term period. Therefore, quick passing showers will move at
times across the USVI and eastern sections of PR, leaving between
0.25-0.50 inches. Lesser amounts are expected over western PR in
shallow afternoon shower development.

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

A broad surface high pressure over the north-central Atlantic will
maintain easterly winds at 10-20 mph through the end of the
workweek, becoming more northeasterly as another broad surface
high pressure streams eastward across the western Atlantic. In the
meantime, mid-to-upper level ridging will support a strong trade
wind cap inversion and drier conditions aloft through most of the
cycle. Nonetheless, a patchy weather pattern will dominate, with
model-estimated precipitable water values ranging between 1.0 and
1.6 inches through Saturday. Patches of low-level moisture will
drive isolated to scattered shower activity, especially with the
weakening of the trade wind cap and a slightly wetter environment
on Wednesday. Still, any resulting shower activity should not
support significant wetting rains or flooding. In contrast,
extended periods under drier conditions will cause further
deterioration of soils and fuels across the local islands and the
potential for fire danger conditions.

The most recent model guidance suggests a transition into a
somewhat moist and unsettled weather pattern by Saturday night
into Sunday. This pattern will result from the proximity of a mid-
to-upper level low system and associated surface-induced feature
to the northeastern Caribbean, causing the weakening of the trade
wind cap inversion and deeper moisture across the region. Enhance
low-level moisture convergence, with precipitable water values
rising to around 1.80 inches, and cooler mid-level temperatures
could support an increase in showers and possible isolated
thunderstorm activity, as well as the potential for flooding
during this period. Nonetheless, since this transition is expected
far in the forecast cycle and model guidance varies with every
solution, there is low confidence in the forecast at this time.


&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. However, trade winds showers
could move at times across the USVI/Eastern PR terminals through the
period causing brief BKN cigs btw FL030-FL060. East winds will
continue at 15-20 kt with with sea breeze variations and higher
gusts after 12/14z.


&&

.MARINE...Moderate to fresh winds up to 20 knots and a small
northerly swell will maintain choppy to hazardous marine
conditions through at least early next week. As a result, Small
Craft Advisories are in place for most local waters due to
building seas up to 8 feet through late Sunday night.

For beachgoers, a high risk of rip currents is also in effect for
beaches across the northwest to northeast and southeast coast of
Puerto Rico and most beaches of Culebra, Vieques, St Thomas, and
St Croix.


&&

.FIRE WEATHER...The most recent KBDI and fuel moisture
observations suggest further deterioration of soils and
vegetation, with Camp Santiago reporting a KBDI of 734 and a
10-hour fuel moisture value of 8 percent. Stable weather
conditions with limited shower activity will prevail once again
today, with the forecast calling for relative humidity values to
drop into the mid to upper 40s and winds peaking around 15-20 mph
or even higher due to sea breeze variations. Lack of significant
wetting rains and the expected weather conditions will support an
elevated fire danger threat. As a result, a Fire Danger Statement
is in place for the southern coastal plains of Puerto Rico.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 74 85 73 / 20 20 50 50
STT 81 72 84 72 / 30 30 50 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
456 AM AST Sun Feb 13 2022

.SYNOPSIS...A generally stable weather pattern with breezy
conditions will prevail throughout the rest of the weekend into
next week. Patches of low-level moisture embedded in the trade
winds will bring isolated to scattered shower activity. In the
meantime, pockets of drier air will further dry soils and fuels,
leading to fire danger conditions. Although the weakening of the
trade wind cap and increasing winds will enhance low-level
moisture convergence and showers by the latter part of the
workweek, the resulting rains should not pose a threat. Moderate
to fresh winds and a fading small northerly swell will maintain
choppy to hazardous marine and surf zone conditions.


&&

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

Breezy conditions and quick passing sowers prevailed once again
across the islands during the overnight hours. Observed rainfall
accumulations were between 0.05-0.15 inches, with the highest
amounts over eastern Puerto Rico. Gusty winds between 26-31 mph were
reported along the southern coasts of St. Croix and Puerto Rico.
Minimum temperatures were from the low 60s across the higher
elevations to the low 70s across coastal areas.

The mid-level ridge just north of the area will continue to hold
through the short term period. Promoting drier air and stable
conditions above 700 mb. However, a polar trough and associated
surface front will exit the Eastern Seaboard of the US on Monday,
causing the mid-level ridge to weaken briefly and allow for better
pooling of moisture on Tuesday, when an induced trough is forecast
to move across the eastern Caribbean. At the surface, fresh trade
winds are expected to continue today under the influence of a low to
mid-level ridge pattern across the Atlantic, decreasing to moderate
on Monday and Tuesday. Embedded in this flow, patches of low-level
moisture and cloudiness will continue to stream from the Tropical
Atlantic. Therefore, expect a similar weather pattern today as
previous days, with a slight increase in shower development over
western PR. Drier conditions are expected on Monday, with
precipitable water(PWAT) values fluctuating between 0.80-.1.10
inches through the day. PWAT increases to around 1.50 inches on
Tuesday, and showers will increase in coverage and intensity.

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

The most recent model guidance now suggests a somewhat drier
weather pattern during the long-term forecast period, dominated by
intermittent patches of relatively drier and moist air streaming
across the region, resulting in significant variations in moisture
levels. At the surface, a developing broad high pressure system
moving further eastward into the north-central Atlantic will
maintain east to east-northeast winds at 10-20 mph and even higher
at times. These pulses in the general wind flow will enhance low-
level moisture convergence, causing precipitable water values to
reach above normal levels (1.4 inches or higher) by Thursday night
into Friday and Saturday night into Sunday. In the meantime,
precipitable waver values should remain around normal to below-
normal levels. Yet, patches of drier air will cause precipitable
water values to plunge below an inch by Thursday afternoon and
Saturday afternoon. Despite moisture variations at the lower
levels, mid-to-upper level conditions will remain significantly
dry and hostile for deep convective development throughout the
period, even with the weakening of the trade wind cap expected
between Thursday and Saturday due to the proximity of a mid-to-
upper level trough. That said, the resulting shower activity will
remain shallow, with isolated to scattered showers producing light
to moderate rains. A slight increase in shower activity can be
expected during periods of highest moisture, but significant
rainfall accumulations nor flooding will result from this
activity.


&&

.AVIATION...Mainly VFR conditions are expected to prevail across
all terminals during the next 24 hours. However, trade winds
showers could move at times across the USVI/Eastern PR terminals
through the period causing at times BKN cigs btw FL030- FL060.
East winds will continue at 15-20 kt with with sea breeze
variations and higher gusts after 13/14z.


&&

.MARINE...Moderate to fresh winds up to 20 knots and a fading
small northerly swell will maintain hazardous marine conditions
through late tonight, improving early next week. As a result,
Small Craft Advisories remain in place for coastal waters of
northern and eastern Puerto Rico, Culebra, Vieques, and the
northern US Virgin Islands through this morning, and for the
offshore Atlantic waters and the Anegada passage through late
tonight.

For beachgoers, a high risk of rip currents also remains in effect
for beaches across the northwest to northeast and southeast coast
of Puerto Rico, the eastern coast of Vieques, the northwestern
coast of Saint Thomas, and most beaches of Culebra and St Croix.


&&

.FIRE WEATHER...Isolated to scattered showers may affect portions
of the southern coastal plains of Puerto Rico at times, but the
resulting rains will not be sufficient to ease the drying
conditions observed across these areas. These showers may keep
fuels relatively wet throughout the day, even when relative
humidity values fall into the lower 40s to lower 50s between the
late morning and early afternoon hours. The local wind flow will
remain from the east to the east-northeast, with winds peaking at
10-20 mph or even higher due to sea breeze variation. So far,
conditions appear to be marginal to support an elevated fire
danger threat, but these conditions could quickly deteriorate with
the entrance of drier air. Further monitoring for fire danger
conditions will continue throughout the day, and a Fire Danger
Statement will be issued if conditions warrant.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 74 83 72 / 50 30 20 50
STT 83 72 84 73 / 50 20 20 60

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
509 AM AST Mon Feb 14 2022

.SYNOPSIS...A mid-to-upper level ridge over the region will
continue to promote drier air aloft and inhibit convective
development today. A weak SAL is forecast to briefly move by
midweek. Precipitable water content after today will increase and
range between 1.20-1.40 inches through next week, which is near
normal values. Life-threatening rip currents continue across the
north and some of the east facing beaches of the islands.

&&

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

Mainly dry and stable weather conditions will prevail today,
transitioning into a slightly wetter pattern late tonight through
the rest of the forecast cycle. A surface high pressure across the
north-central Atlantic will maintain moderate to locally fresh east
northeast winds at 10 to 20 mph with higher gusts. Mid-levels will
remain dry and hostile, with mid-level ridging holding a strong
trade wind cap inversion and drier air aloft. A drier air mass, now
moving into the forecast area, with satellite-derived precipitable
water values as low as 0.70 inches, will maintain generally fair
weather conditions. However, a patch of low-level moisture will
quickly follow, bringing isolated to scattered shower activity to
portions of the USVI and eastern Puerto Rico later this morning into
the early afternoon hours. Although limited, near-normal moisture
aided by local effects and diurnal heating will support afternoon
convective development across the far western sections of Puerto
Rico. Conditions will quickly dry out with the entrance of another
band of drier air, limiting any chance for shower activity through
early tonight. Across lower elevations, daytime highs will reach the
lower to mid-80s, while overnight lows will fall into the upper 60s
to lower 70s.

With the weakening of the mid-level ridge and passage of a surface-
induced trough, somewhat favorable conditions aloft and enhanced low-
moisture convergence will cause precipitable water values to rapidly
reach normal to above-normal moisture levels late tonight into
Tuesday. This scenario will lead to a higher frequency of
overnight/early morning showers moving over the USVI and eastern
Puerto Rico, followed by afternoon convective development across the
interior to western Puerto Rico and downwind from the local islands
and El Yunque. Moderate to locally heavy rains, producing between a
quarter to half an inch, could lead to ponding of water on roadways
and poorly drained areas.

By Tuesday night into Wednesday, expect improved weather conditions
and limited shower activity as moisture gradually erodes. In
addition, following the most recent model guidance, expect hazy
conditions with the entrance of lower concentrations of Saharan dust
particulate into the northeastern Caribbean.

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

The mid-level ridge is forecast to build once again west of the
region through the long term period. At the surface, a broad ridge
is expected to move into the central Atlantic on Wednesday and
move over the Azores by Sunday. This will cause breezy conditions
once again during the end of the workweek. Meanwhile, a mid-to-
upper level trough will move over the Tropical Atlantic during the
weekend. This will promote TUTT induced perturbations and enough
low-level moisture content for the trade winds to bring the
occasional passing showers across the islands. This small surge in
moisture will aid in the development of diurnally induced
afternoon showers. Winds are expected to have a northeasterly
component through the long term period. Therefore, nighttime/early
morning showers will favor the east/northeast sections of PR and
the USVI, and afternoon showers should develop mainly over the
southwestern portions of PR.


&&

.AVIATION...Mainly VFR conditions are expected. However, patches of
low-level clouds and isolated to scattered SHRA could result in
brief MVFR conditions across TSJU, USVI, and the Leeward terminals
through 14/14Z. Minimal impacts to operations are expected between
14/14-22Z. Surface winds will remain light and variable, turning
from E to ENE and increasing to 10-20 knots with higher gusts after
14/14Z.


&&

.MARINE...Moderate to locally fresh trades will continue to
promote choppy seas up to 6 feet across the most of the local
waters during the next few days. A fading swell and wind driven
seas will continue to result in a high risk of rip currents across
the northern and eastern beaches of PR, including Culebra, and
St. Croix. The risk will remain high through much of the week, and
the High Rip Current Risk will likely be extended.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 84 73 / 20 60 60 60
STT 84 72 84 73 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
439 AM AST Tue Feb 15 2022

.SYNOPSIS...A weak Saharan Air Layer will move over the region
from late tonight through Thursday. Breezy conditions are
expected during this period. Trade winds will continue to carry
areas of shallow moisture from the Tropical Atlantic through the
long term period. A northeasterly wind component will favor
showers across the USVI and east/northern sections of Puerto Rico
during the night/morning hours, then over west/southwest PR in the
afternoons. Choppy seas and life threatening rip currents are
expected into the upcoming weekend.


&&

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

A transition into slightly wetter conditions is expected, holding
through the short-term forecast cycle, even with the entrance of
lower to moderate concentrations of Saharan dust particulate by this
evening and the erosion of the available moisture Wednesday into
Thursday. Mid-level ridging and the trade wind cap inversion will
weaken as a polar trough over the western Atlantic lifts to the east
today, resulting in somewhat favorable conditions for organized deep
convective development and deeper moisture to move into the region.
At the surface, moderate to locally fresh east northeast winds at 10
to 20 mph, generated by a surface high pressure over the north-
central Atlantic, will advect patches of low-level moisture across
the area. Supported by a cool advective pattern, expect trade wind
showers moving over northeastern Puerto Rico and the US Virgin
Islands through the rest of the morning hours, followed by streamers
moving into eastern Puerto Rico and the San Juan Metropolitan area
late in the afternoon. Normal to above-normal moisture content,
increasing up to 1.5 inches through this evening, combined with
local effects and diurnal heating, will support afternoon convective
development, clustering across the interior and west to southwestern
sections of Puerto Rico. The expected rainfall accumulations of up
to half an inch with isolated higher amounts could lead to ponding
of water on roadways and poorly drained areas. Across lower
elevations, daytime highs will reach the lower to mid-80s, while
overnight lows will fall into the upper 60s to lower 70s.

By this evening and continuing through at least Thursday evening,
mid-level ridging will gradually re-establishes over the
northeastern Caribbean, supporting the development of the trade wind
cap and drier conditions aloft. In addition, the most recent aerosol
model guidance suggests that some Saharan dust particulate will move
into the region, with lower to moderate concentrations leading to
hazy skies through the end of the forecast cycle. Although the
environment will slowly become unfavorable for deep convective
development, with the gradual erosion of the available moisture,
moisture content should remain near normal seasonal levels,
supporting limited shower activity following the seasonal shower
pattern. Mid-to-upper levels conditions will not change much, but a
slight increase in shower activity can be expected by Thursday night
with the passage of yet another patch of low-level moisture.


.LONG TERM...Friday through Wednesday...

A mid-to-upper level ridge is forecast to build over the western
Caribbean through the period. Two upper level troughs are forecast
to move just northeast of the region and slightly weaken the
ridge. The first one on Friday and the other one between
Tuesday/Wednesday. At the surface, a broad ridge over the central
Atlantic will shift further east and hold over the Azores through
Monday. Meanwhile, a TUTT induced trough is forecast to develop
a few hundred miles northeast of the Leeward Islands by early
next week. In response, moderate to fresh northeasterly trade
winds will prevail through the long term period, and moisture
advection will favor nighttime/early morning showers across the
USVI and northeastern sections of PR, followed by shallow
afternoon shower development over the southwestern quadrant of PR
each day.


&&

.AVIATION...Mainly VFR conditions are expected. However, clusters of
low-to-mid level clouds and SHRA could result in brief MVFR
conditions across TSJU, USVI, and the Leeward terminals through
15/14Z. Minimal impacts to operations are expected between 15/14-
22Z, but an increase in passing SHRA could lead to brief MVFR
conditions after 15/22Z. Surface winds will remain light and
variable, turning from E to ENE and increasing to 10-20 knots with
higher gusts after 15/14Z.


&&

.MARINE...Increasing winds and building seas are expected during
the next several days. A northerly swell is forecast to move
across the Atlantic waters and local passages from Wednesday into
the weekend. Seas will become hazardous to small crafts across
the offshore waters starting late tomorrow. Life-threatening rip
currents are expected to continue through the weekend across most
of the north and east facing beaches of all the islands. Please
refer to the latest Coastal Hazard Message (CFWSJU) and Marine
Weather Message (MWWSJU) during the next couple of days as
additional land/marine zones will be added to the hazards
products.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 85 73 / 60 50 40 50
STT 84 73 84 73 / 40 40 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
508 AM AST Wed Feb 16 2022

.SYNOPSIS...Breezy conditions and a weak SAL will continue across
the region through at least Thursday. A seasonal weather pattern
is expected to prevail during the next several days. However, an
increase in shower activity is possible on Friday and by midweek
next week. Hazardous marine and coastal conditions across most of
the regional waters and coastal areas of all the islands will
continue through the weekend.


&&

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

During the forecast cycle, a surface high pressure centered over
the north-central Atlantic will maintain a dominant east to east-
northeast wind flow. The resulting brisk steering flow up to 20
knots will advect patches of low-level moisture into the forecast
area, maintaining normal to above-normal moisture levels across
the region, with precipitable water values ranging between 1.2 and
1.6 inches through the forecast cycle. Ridging will remain the
dominant feature at mid-to-upper levels, supporting a strong trade
wind cap inversion and drier conditions aloft. Despite hostile
conditions for deep convective development, a high frequency of
fast-moving showers will affect the northern and eastern sections
of the local islands through the rest of the morning hours,
followed by shallow afternoon convective development across the
far western sections of the island. Streamer-like showers moving
over eastern Puerto Rico and the San Juan Metropolitan area cannot
be ruled out later in the afternoon. Overall, light to moderate
rains could produce rainfall accumulations between a quarter to
half an inch, with isolated higher amounts likely, leading to
ponding of water on roadways and poorly drained areas. Elsewhere,
lower concentrations of Saharan dust particulate could result in
hazy conditions in areas with limited to no shower activity.
Across lower elevations, daytime highs will reach the lower to
mid-80s and even upper 80s across southwestern Puerto Rico, while
overnight lows will fall into the upper 60s to lower 70s.

Although model guidance suggests a gradual erosion of the available
moisture throughout the rest of the forecast cycle, a set of patches
of low-level moisture embedded in the trade winds will maintain
precipitable water values near normal seasonal levels. This scenario
will continue to support a seasonal shower pattern dominated by
overnight/early morning showers moving over windward areas. Limited
afternoon convective development remains likely, though focused over
the far western sections of the island with streamers possible over
the east. A slight weakening of the mid-to-upper ridge could
increase shower activity by Thursday night, but significant wetting
rains nor flooding are anticipated. The concentrations of Saharan
dust particulate will decrease through the end of the workweek, but
hazy conditions are possible.

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

A mid-to-upper level ridge is expected to build once again from
the west during the weekend, and an upper level trough will shift
further east of the Lesser Antilles. At the same time, a surface
high pressure will remain anchored over the Azores, while a TUTT
induced low-level trough develops just northeast of the Leeward
Islands. In response to evolving synoptic patter, winds will have
a northeasterly component, and favor moisture advection across the
northeastern Caribbean through much of the long term period. By
midweek, a deep layered low is forecast to develop over the
central Atlantic and sink south just to the northeast of the
region. This is expected to cause a weakening of the trade wind
cap, and promote better columnar moisture for showers to increase
in coverage and intensity. In general, a similar weather pattern
is expected through the long term period, with trade wind showers
moving over portions of the USVI and east/northeast PR during the
night and early morning hours, followed by shallow afternoon
convection over southwestern PR.


&&

.AVIATION...Mainly VFR conditions are expected. However ,
increasing cloud cover and fast-moving SHRA could result in brief
MVFR conditions across northern PR, USVI, and the Leeward
terminals through 16/14Z. Minimal impacts to operations are
expected between 16/14-22Z, but an increase in SHRA could lead to
brief MVFR conditions after 16/22Z. Surface winds will remain from
the E to ENE at 5-15 knots, increasing to 10-20 knots after
16/14Z. Higher gusts are expected, mainly near the shower
activity.


&&

.MARINE...Fresh trade winds and building seas are expected to
continue through at least Thursday across the regional waters.
A northerly swell is forecast to move across the Atlantic waters
and local passages by late tonight, and slowly subside through the
weekend. Therefore, hazardous seas and life threatening rip
currents are expected to continue into the weekend. Please
refer to the latest Coastal Hazard Message (CFWSJU), Surf Zone
Forecast (SRFSJU) and Marine Weather Message (MWWSJU) for
detailed information.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 83 73 / 60 60 60 50
STT 84 73 83 72 / 30 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
501 AM AST Sat Feb 19 2022

.SYNOPSIS...

The islands will continue under a northeasterly wind flow through
the end of the workweek. Expect a mixture of sunshine and clouds
with a few passing showers across the windward sections of Puerto
Rico and the U.S Virgin Islands through the morning hours, and
afternoon convection will develop across the western portions. A
surface perturbation could result in rainy conditions on Monday.

&&

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

A surface high pressure over the northeast Atlantic is inducing an
northeast flow across the islands through early next week. In terms
of moisture content, the GOES precipitable water analysis showed a
few patches of low level moisture with values around 1.2 inches
upstream of the islands. This drier air mass will spread over the
islands the rest of today, resulting in less shower coverage
compared to yesterday. Local effects and sea breeze convergence will
help to form some showers over southwest of Puerto Rico this
afternoon. No significant rainfall accumulations are anticipated
with the afternoon showers as mid-level ridge will limit the
vertical development of the showers. On Sunday, the advective
pattern will contribute to passing showers at night and early in the
morning across the windward areas. The afternoon convection will
focus again over southwest Puerto Rico.

By Monday, an induced surface trough located over the north central
Atlantic will move southwestward over Puerto Rico and the U.S.
Virgin Islands. This area of higher moisture and instability will
promote scattered to locally numerous showers over portions of north
and east Puerto Rico as well as Culebra, Vieques and the U.S. Virgin
Islands on Sunday morning. Then, additional cloudiness and showers
will spread over the rest of Puerto Rico during the afternoon hours,
leading to ponding of water in some spots.

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

A mid to upper-level ridge will continue over the Northeast
Caribbean through Tuesday or Wednesday. Then it is forecast to
weaken as a mid to upper- level trough amplifies near the
Northeast Caribbean from the Central Atlantic. Although the ridge
aloft will promote stable weather conditions, the trade winds will
bring patches of clouds and showers across Puerto Rico and the
U.S. Virgin Islands at times.

Upper-level low digs southward and re-locates east or northeast
of the Lesser Antilles from mid-week to the following weekend.
Although the ridge should weaken, the islands will remain on the
subsidence side of the low pressure aloft. However, cold air
advection will promote the typical overnight and early morning
showers, followed by limited afternoon convection across the
western sections. Surface-induced troughs will bring more frequent
showers Friday and Saturday.

&&

.AVIATION...

VFR conds expected through the forecast period under a generally
fair weather pattern. NE winds at around 15KT with higher gusts
are expected across the flying area. VCSH possible near TJSJ, TJBQ
and TIST at times under this NE flow.


&&

.MARINE...

Moderate chop to choppy seas will prevail due to moderate to fresh
winds. Seas up to 7 feet will continue across the offshore
Atlantic waters throughout Monday. Elsewhere, seas between 3 and 6
feet will persist throughout the forecast period. The winds will
persist out from the northeast and should increase by the next
mid-week.

For the beaches, the risk of rip currents is high for the northern
and eastern coast of Puerto Rico, Culebra, Vieques, and all of the
U.S. Virgin Islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 73 82 73 / 40 50 40 70
STT 84 73 82 73 / 20 30 30 50

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Sun Feb 20 2022

.SYNOPSIS...

The northeasterly wind flow will promote pleasant temperatures
across the islands as well as a few showers affecting the
windward sections of Puerto Rico and the U.S Virgin Islands each
day. Local effects and sea breeze variations will aid in
developing afternoon showers across the southwest quadrant of
Puerto Rico and downwind from the Virgin Islands.

&&

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

Moderate northeasterly winds will continue across the region over
the next several days. This cold advective pattern will continue to
favor passing showers across portions of the local islands
especially the windward sections at night and early in the morning.
Then, local effects and sea breeze convergence will combine to
produce scattered showers over the southwest portions of Puerto Rico
each afternoon. Mid-level ridge will hold through early next week,
keeping a relatively stable and dry air aloft that will limit the
vertical development of the showers. The GFS model cross section
over Puerto Rico suggests that the best moisture will spread over
the region this afternoon into Monday morning. During this period
the frequency of passing shower will increase slightly and the
afternoon convection will likely last more. Similar conditions are
forecast Monday and Tuesday, with morning showers affecting the
north and east sections of the islands followed by some showers over
southwest Puerto Rico and downwind of the small islands each
afternoon.

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

A mid to upper-level trough will amplify near the Northeast
Caribbean from the Central Atlantic, weakening the ridge pattern
aloft. This upper-level low will re-locates east or northeast of
the Lesser Antilles from mid-week to the following weekend. At
this time, the islands will remain on the subsidence side of the
low pressure aloft. However, cool air advection will result in
trade wind showers across the northeast Caribbean, promoting the
typical overnight and early morning showers across the windward
sections. It will be followed by limited afternoon convection
across the western portions. Surface-induced troughs will bring
more frequent showers on Friday and Sunday.

&&

.AVIATION...

VFR conds expected across the TAFs through the forecast period.
Passing -SHRA or VCSH could moved briefly over or near TJSJ, TJBQ
and TIST but not operational impact is anticipated. NE winds at
around 15-20KT with higher gusts will prevail below FL150.


&&

.MARINE...

Mariners should exercise caution due to seas 4 to 6 feet with
occasional seas up to 8 feet across most local waters, especially
in the offshore Atlantic waters and Mona Passage. The winds will
persist out from the northeast and should increase after mid-week.

For the beaches, the risk of rip currents is high for the northern
and eastern coast of Puerto Rico, Culebra, and St Croix. The risk
will also become high for St Thomas and Vieques this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 72 83 73 / 40 60 30 40
STT 84 73 84 73 / 30 50 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
352 AM AST Mon Feb 21 2022

.SYNOPSIS...
Northeasterly winds are expected to prevail for the next several
days. Under this pattern, passing showers will continue to affect
the northern and eastern Puerto Rico, as well as the United Virgin
Islands. The frequency of showers is expected to increase by early
next week. Hazardous marine conditions are expected for the
Atlantic waters through the end of the week.

&&

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

Moderate east to northeast winds will continue across the region
over the next several days. This pattern will continue through the
short term period, and will promote brief showers, mainly affecting
the north and east sections of PR and the USVI during the night and
early morning hours. For the afternoon hours, the combination of the
diurnal heating, available moisture and sea breeze convergence will
cause locally induced shower activity. With the expected wind flow,
these afternoon showers are expected to develop across the
southwestern quadrant of PR. The rest of PR and the USVI would
expect fair weather or brief isolated showers. Mid and upper level
ridge will hold through Tuesday, keeping it relatively stable, but a
mid to upper low will start developing on Wednesday. This mid and
upper level low will cause a surface induced trough to the east of
the local islands, and drier air will sink in early on Wednesday.
However, the relatively strong winds at all levels, may cause a
showery pattern through the local area, but the afternoon convection
over SW-PR may be limited since the sea breeze convergence is not
expected to be very strong.

.LONG TERM...Thursday through Monday...
A mid to upper level low pressure will approach the northeastern
Caribbean on Thursday. At the surface, an induced trough will
maintain the wind flow from the northeast. So far, the islands
should stay in the subsidence side of the low, while a surface to
mid level high pressure builds near the Bahamas. In response, a
trade wind cap should form around 700 mb, trapping all the
moisture below that. Under a northeasterly wind flow, an advective
pattern will be favored, with passing showers affecting the
northern and eastern sections of Puerto Rico as well as the U.S.
Virgin Islands. Moisture amount should be limited, though, with
precipitable water values around 1.0 inch. Therefore, any shower
that may form in the southwest in the afternoon should not leave
significant rainfall amounts.

For Friday and Saturday, the surface trough begins to move toward
the west, and in response, the winds shift from the east. Moisture
amounts are expected to remain limited, and the global models, as
well as the National Blend Model, agree on only a slight chance of
afternoon convection developing in the afternoon across western
Puerto Rico. By Saturday evening and into Sunday, the field of
moisture associated with the trough approach should begin to cross
the local islands. Since the mid to upper level low will virtually
remains in the same place, although weaker, this will allow for
moisture to flow deeper into the mid levels of the atmosphere.
Additionally, the wind flow should turn from the southeast by Sunday
evening. Precipitable water values are expected to be around 1.6
inches on Sunday, and near 1.8 inches on Monday, which is above the
climatological value. As a result, a wetter weather pattern is
expected for the last couple of days of February.


&&

.AVIATION... Except for TJPS, which will observe fair weather
overnight, scattered to numerous showers over the local flying area
will cause VCSH through at least 21/14Z, with brief -SHRA at the
actual terminals. After 21/16Z, SHRA to develop across W-SW PR,
possibly causing VCSH at TJPS. Winds prevailing from the E-NE
through the forecast period, generally at 10KT or less through
21/13Z, but increasing to around 15KT and gusty thereafter. Winds at
TJPS will be from the ESE after 21/14Z due to sea breeze variations.


&&

.MARINE...
Choppy seas due to moderate winds are expected to prevail today.
However, winds will increase tomorrow, and seas are expected to
reach small craft advisory criteria across the offshore Atlantic,
and possibly across the local passages. These conditions are
expected to persist through at least the end of the workweek. For
the beaches, the risk of rip currents is high for the northern
coast of Puerto Rico, Culebra, northern St. Thomas, and eastern
and northern St. Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 83 73 / 30 30 40 40
STT 84 72 83 73 / 30 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
343 AM AST Tue Feb 22 2022

.SYNOPSIS...
Seas will increase today, becoming hazardous across the Atlantic
waters, and these conditions should persist through the end of the
week. Passing showers will continue to affect the local islands at
times, with scattered to numerous activity expected for the
interior and west of Puerto Rico. Limited moisture is expected for
the end of the week, but shower frequency could increase by Sunday
and early next week.

&&

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

Model guidance insists that moderate east to northeast winds will
continue across the region through the short term period, and will
promote brief showers, mainly affecting the north and east sections
of PR and the USVI during the night and early morning hours. For the
afternoon hours, the combination of the diurnal heating, available,
though limited, moisture and sea breeze convergence will cause
locally induced shower activity. With the expected wind flow, these
afternoon showers would develop across the southwestern quadrant of
PR. The rest of PR and the USVI can expect brief isolated to
scattered showers, if that, during the afternoon hours. Mid and
upper level ridge will hold through today, keeping conditions
relatively stable, but a mid to upper low will start developing on
Wednesday. This mid and upper level low will cause a surface induced
trough to the east of the local islands, and drier air will sink in
early on Wednesday. However, the relatively strong winds at all
levels, may cause a showery pattern through the local area, but the
afternoon convection over SW-PR may be limited since the sea breeze
convergence is not expected to be very strong. By Thursday, the mid
and upper level low and associated trough, will have its axis to the
SE of the local islands, but the winds in the mid and upper level
continue stronger than normal. Therefore, once again, scattered
showers are forecast across the local waters, N and E PR as well as
the USVI during the overnight into early Thursday, then SCT SHRA
across SW-PR on Thursday afternoon. That being said, the rainfall
amounts are not expected to cause flooding over a large area, though
minor urban flooding across isolated areas will not be ruled out.

.LONG TERM...Friday through Tuesday...
An induced surface trough east of the Lesser Antilles will maintain
the wind flow coming from the northeast on Friday. At the mid to
upper levels, a closed low pressure system continues to the
northeast of the region, while a mid level ridge is building near
the Bahamas. Since the islands will be located on the subsidence
side of the low pressure, the mid levels will remain dry, with the
GFS forecast soundings showing a trade wind cap around 850 mb. In
general, an advective pattern will be favored, with passing showers
affecting the northern and eastern municipalities of Puerto Rico, as
well as the U.S. Virgin Islands. As is usual, available moisture
should then combine with local effects to generate additional
activity over the interior and western Puerto Rico. A similar
pattern is expected on Saturday, but with the winds turning from the
east as the trough progresses westward.

By Sunday, the upper level low opens into a trough while weakening.
The surface reflection of this feature will continue to advance
toward the local islands, increasing precipitable water values to
1.4 to 1.6 inches and switching winds from the southeast from Sunday
through Tuesday. The moisture field is expected to stretch into the
mid-levels, and also, temperatures at the mid-levels are expected to
cool down to -6 to -7 degree Celsius, which should translate into an
atmosphere more favorable for showers and possible isolated
thunderstorms development.


&&

.AVIATION...Except for TJPS, which will observe fair weather,
scattered SHRA over the local flying area will cause VCSH through at
least 22/14Z, with possible brief -SHRA at the actual terminals.
After 22/16Z, SHRA to develop across W-SW PR, possibly causing VCSH
at TJPS. Winds prevailing from the E-NE through the forecast period,
generally at 10KT or less through 22/13Z, but increasing to around
15KT and gusty thereafter. Winds at TJPS will be from the ESE after
22/14Z due to sea breeze variations.


&&

.MARINE...
Recent observations show seas at 3 to 5 feet across the local
waters. However, seas will become choppy later today, and reaching
small craft advisory criteria by this afternoon and evening across
the offshore Atlantic. This is due to increasing winds, and these
conditions should persist through the end of the week.

For the beaches, there is a high rip current risk for the north
and east-facing beaches of Puerto Rico, Vieques, Culebra, northern
St. Thomas and northern and eastern St. Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 82 72 / 40 40 40 30
STT 84 72 83 72 / 40 40 40 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
408 AM AST Wed Feb 23 2022

.SYNOPSIS...
Passing showers will continue to affect the local area through the
next several days, under a northeasterly wind flow. Increasing
winds will result in hazardous seas for the offshore Atlantic
waters through Friday. Shower activity could become more frequent
by the beginning of the next workweek.

&&

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

Model guidance insists that moderate east to northeast winds will
continue across the region through Thursday, becoming slightly
easterly on Friday. The weather pattern will not change much,
promoting brief showers, affecting the north and east sections of PR
and the USVI during the night and early morning hours. For the
afternoon hours, the combination of the diurnal heating, available,
moisture and sea breeze convergence will cause locally induced
shower activity. With the expected wind flow, these afternoon
showers would develop across the southwestern quadrant of PR each
afternoon, including Friday. The rest of PR and the USVI can expect
brief isolated to scattered showers, during the afternoon hours.
Based on the latest guidance, today Wednesday could be the rainiest
day in the short term period, as it is the day with the highest
moisture. Ponding of water on roadways and poor drainage areas are
expected across portions of PR over the next few days, but NE-PR
could observe minor urban flooding today in isolated areas.

Strong mid and upper level low to the northeast of the Leeward
islands will have stronger than normal winds in the mid and upper
levels locally, buy the local islands will remain in the subsident
side, as the low meanders over the area for the next few days.

.LONG TERM...Saturday through Wednesday...
The upper level trough, associated mid-level low pressure, and
surface trough reflection will be located to the east of the
islands on Saturday. Therefore, the area should stay in the
subsidence side of this feature, unfavorable for strong shower
development. Regardless, some showers are still expected to be
dragged by the trade winds across the region at times. By Sunday,
as the surface trough progresses westward, the wind flow will
shift from the southeast, allowing for better moisture to filter
into the area.

By Monday, another polar trough will begin to exit the eastern
coast of the United States. This will act to weaken a mid-level
ridge over the western Caribbean, thus allowing for deeper
columnar moisture through mid-week. A cold front will also be
moving out of the U.S. coast, and although is not expected to
reach the local islands, it will aid in maintaining the wind flow
from the southeast and inducing additional surface trough near the
region. Therefore, an increased frequency of showers can be
anticipated for the first half of the workweek.


&&

.AVIATION...
TJPS, which will observe VCSH through the day, but the
rest of the local terminals will observe -SHRA through the morning
hours, with VCSH in the afternoon. After 23/16Z, SHRA to develop
across SW PR, continuing VCSH at TJPS. Winds prevailing from the NE
at 10KT or less through 23/14Z, but increasing to around 15KT and
gusty thereafter. Winds at TJPS will be from the ESE after 23/14Z
due to sea breeze variations.


&&

.MARINE...
The outer buoy (41043) has been reporting seas at 7 to 8 feet
since yesterday, with a swell component coming from the northeast.
This should result in hazardous seas for the offshore Atlantic,
where a Small Craft Advisory continues in effect. These conditions
should stretch into the end of the workweek. Elsewhere, increasing
winds will create choppy seas at 4 to 6 feet.

For the beaches, the risk of rip currents continue to be high for
the northern coast of Puerto Rico, as well as some beaches in
Culebra, Vieques, northern St. Thomas and northern and eastern St.
Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 72 82 72 / 60 30 30 30
STT 83 72 84 73 / 50 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Thu Feb 24 2022

.SYNOPSIS...North to northeast winds will continue today, but
will change to easterly winds on Friday and will continue for the
next several days. This is due to a strong surface high pressure
over the east central Atlantic, which will dominate the local wind
flow. Drier air is moving today but brief showers will continue
to move over the local area. This drier air will continue through
the weekend, but near normal to above normal moisture is expected
for the upcoming workweek. Marine conditions will be choppy to
hazardous for the rest of the workweek, and the high risk of rip
currents will continue for the next several days.


&&

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

A mid to upper level trough is currently located just to the
northeast of the Leeward Islands, while a mid level ridge is
centered around Florida. A surface trough associated with this
feature is currently producing winds out of the northeast at 10 to
15 knots. The local islands are on the subsidence side (unfavorable
for shower development) of the trough, with a trade wind cap
inversion around 850 mb. Any available moisture should be trapped
below this level, but recent precipitable water satellite-derived
imagery, as well as the GFS forecast sounding, show that relatively
dry air is advancing over the islands. In general, the shower
activity should be limited today, but still with the potential for
some brief showers along the northern and eastern coast of Puerto
Rico and the U.S. Virgin Islands in the morning. Some showers could
also fire up across the southwestern quadrant of Puerto Rico, but
amounts should remain light.

For tomorrow and Saturday, a similar pattern is anticipated. The
upper level trough digs further south, while the surface reflection
advances toward the islands. This will allow for the trade wind cap
to lift to around 700 mb, and a little bit more moisture should
filter in from the east. A rainy pattern is not anticipated, but the
frequency of showers could increase in the morning for northeastern
Puerto Rico and the U.S. Virgin Islands, and stronger showers could
develop in western Puerto Rico during the afternoon hours.

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

Strong surface high pressure across the east central Atlantic will
promote easterly winds through the log term period. The available
moisture will be near to slightly above normal from Monday onward.
The weather pattern will be typical for easterly winds with near
normal moisture. Isolated to scattered showers in the morning
across the USVI, eastern PR and the local waters, followed by
afternoon convection across the central to western sections of PR.
However, an enhanced chance of showers, probably more widespread
shower coverage could be expected late in following workweek, as
moisture increases even more, and a weak mid to upper level
trough approaches the local islands from the west, causing some
instability over the local area.

&&

.AVIATION...Mainly VFR conditions expected to prevail across all terminals. VCSH
are expected between 12-15Z, which could cause brief periods of
reduced VIS and low ceilings. For TJPS, VCSH are also expected after
14Z. Winds will be out of the of the NE at 13 knots, with stronger
gusts and sea breeze variations.


&&

.MARINE...The latest guidance suggests hazardous seas for the
offshore Atlantic waters, but the nearshore buoy of San Juan is
reporting seas of near to just over 6 feet. So the marine
forecast was adjusted slightly to increase the wave heights
expected for the coastal Atlantic waters. However, it still did
not suggest seas of 7 feet or higher, and therefore there is a
Small Craft Advisory only for the offshore Atlantic waters. That
being said, careful monitoring will be done through the day
because the seas are very choppy and the model guidance may be
under-estimating a little bit. However, the current forecast is
for seas of 7 feet or higher across the offshore Atlantic waters,
while the rest of the local waters could observe seas up to around
5 or 6 feet. The high risk of rip currents continues for the next
several days, especially for the northwester through northeastern
beaches of PR, Culebra, and the USVI.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 71 83 72 / 40 40 40 50
STT 84 71 84 72 / 40 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST Fri Feb 25 2022

.SYNOPSIS...Easterly winds are forecast today continuing for the
next several days. This is due to a surface high pressure over
the east central Atlantic, which will dominate the local wind
flow. Even though we still expect below normal moisture today, the
available moisture is expected to increase slightly, bringing
isolated to scattered showers. The slightly below normal moisture
is expected through the weekend, but near normal to above normal
moisture is expected for the upcoming workweek. Marine conditions
will be choppy to hazardous into this afternoon for the offshore
Atlantic waters, but will remain choppy elsewhere today and
through the rest of the weekend. The high risk of rip currents
will continue for the next several days.



&&

.SHORT TERM...Today through Sunday...
A mid to upper level low is currently located to the northeast of
the Leeward Islands. This feature, along with a mid level ridge
centered over Florida is generating a wind flow coming out of the
north, and carrying dry air at these levels. An induced surface
trough associated with this low is moving westward, and as a result,
the low level winds are expected to shift from the east today.
Recent satellite imagery shows an area of slight enhanced moisture
moving across the area. This should promote an advective pattern
along the U.S. Virgin Islands and eastern Puerto Rico throughout the
day. In the afternoon, local effects will trigger additional
activity over southwestern Puerto Rico, with moderate rainfall
amounts expected.

On Saturday, a similar pattern is expected to prevail across the
region. The upper level low will open into a trough, but remaining
to the northeast of the islands. By Sunday, the mid-level ridge
weakens, allowing for moisture to reach 500 mb. The moisture will be
provided by another induced surface trough that should cross the
islands during the day. Conditions appear favorable for an increase
in the frequency of showers, but basically following the same
pattern as before: advective showers moving over the eastern
sections of the forecast area during the day, followed by convection
developing over western Puerto Rico in the afternoon.

.LONG TERM...Monday through Saturday...

A surface high pressure across the east central Atlantic is still
forecast to promote easterly winds through the log term period.
The available moisture will be near to slightly above normal from
Monday onward, with Monday having the highest amount of
precipitable water according to the global models. The weather
pattern will be typical for easterly winds with near normal
moisture. Isolated to scattered showers in the morning across the
USVI, eastern PR and the local waters, followed by afternoon
convection across the central to western sections of PR. However,
with the additional moisture expected on Monday, the latest
guidance suggests a wider coverage of shower activity over the
islands compared to the rest of the week. In previous model runs,
the GFS model suggested a mid to upper level trough approaching
the local area late in the workweek. However, this is not the case
with the latest model run, keeping the local islands under a mid
and upper level ridge, while a trough develops well to the east of
the local islands, not for this weekend, but for next weekend.
Given the changes in model guidance from one day to another, the
long term forecast confidence is low.


&&

.AVIATION...SHRA will affect TJSJ/TIST through the morning hours, but conditions
should mainly remain MVFR. In the afternoon, additional SHRA
activity is expected for TJPS, which could result in brief
reductions in VIS and low ceilings. Winds will shift from the east
after 12Z, at 10 to 12 knots with stronger gusts and sea breeze
variations.


&&

.MARINE...The local nearshore buoys are reporting seas of under 6
feet, and the outer buoys are hovering just over 6 feet. The
latest guidance is not suggesting seas reaching 7 feet, but
showing that it will be just over 6 feet across the offshore
Atlantic waters. Model guidance and observation comparison, has
suggested that the models are under-estimating wave heights
slightly. Because of that, it was decided to keep the Small Craft
Advisory for the offshore Atlantic waters through early this
afternoon. If by chance the models are under-estimating more than
it si currently, the advisory may be extended until early
Saturday. As it is currently in the forecast, seas up to 6 feet
but occasionally to 8 feet are expected across the offshore
Atlantic waters for later this afternoon and tonight. Elsewhere,
seas up to 5 or 6 feet are expected with easterly winds up to 15
knots.

There is still a high risk of rip currents for many of the local
beaches, such as those from the northwest to northeast Puerto
Rico, Culebra, northwest St Thomas and most beaches of St Croix.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 84 73 / 50 40 30 30
STT 83 72 84 74 / 40 40 20 50