Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
511 AM AST Wed Jan 30 2019

.SYNOPSIS...A mid level ridge just northeast of the region will
continue to suppress shower activity across the islands through
the end of the week. A weak surface high pressure over the central
and eastern Atlantic will promote light to moderate trade winds
through the weekend. Small surges of low level moisture are
expected to move at times from the east.


&&

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

Upper level ridge will continue to hold across the forecast area
through Thursday. This feature is expected to weaken Friday into the
upcoming weekend as a broad upper level trough moves north of the
local area. At lower levels, a high pressure across the central and
the northeast Atlantic will continue to promote easterly winds
across the local isles. Although the ridge aloft will continue to
dominate the local weather regime, patches of low level moisture
will continue to move at times, increasing the PW values around 1.25
inches which is near normal.

Therefore, continue to expect fair weather conditions with mostly
sunny skies throughout the day today. Showers if any, will be
focused across the eastern coastal areas as well as in the vicinity
of Las Marias and Maricao. Moisture advection is likely tonight,
however, showers will continue to be brief and focused across the
eastern third of Puerto Rico during the overnight hours. On
Thursday, once again plenty of sunshine is expected as the area of
low level moisture moves away. Under weakening ridge, there is a
higher chance for passing showers across the eastern coastal areas
as well as locally induced afternoon showers across west Puerto Rico
on Friday.

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

The mid level ridge is expected to slowly collapse during the
weekend as an upper level trough north of the region press
against it. Therefore, fair weather conditions are expected to
continue across Puerto Rico and the U.S. Virgin Islands through
the weekend. A weak surface low is forecast to develop over the
southwestern Atlantic and move slowly north of the region by early
next week. This will promote light to gentle winds as well
moisture pooling over the islands through midweek. Scattered to
locally numerous showers are possible during this period across
the forecast areas. A surface high pressure is forecast to build
behind the low and across the western Atlantic, promoting a moist
northeast wind flow over the region through the long term period.


&&

.AVIATION...VFR conditions are expected to prevail at all TAF sites
through the forecast period with VCSH possible in and around JMZ aft
16z. Easterly winds near 10 knots early this morning becoming at
around 12 knots with some sea breeze variations aft 12z.


&&

.MARINE...A northerly swell will increase seas up to 6 feet later
tonight through Thursday across the Atlantic waters. This will
increase the risk of rip currents along the northern beaches of
the islands. Elsewhere, seas will range between 3-5 feet through
the end of the week. Light to moderate trades will prevail for the
next several days. There is a moderate risk of rip currents today
for the north and east facing beaches of PR and the USVI.


&&

.FIRE WEATHER...Elevated fire weather conditions along the southern
coastal plains of Puerto Rico today. Please refer to the latest
fire weather forecast (FWFSJU) and fire danger statement (RFDSJU) for
more information.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 84 73 / 20 50 20 40
STT 83 72 83 73 / 40 50 20 40

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
506 AM AST Thu Jan 31 2019

.SYNOPSIS...A mid level ridge will continue to promote drier air
aloft and fair weather conditions through early in the weekend.
Light to moderate trades will prevail for the next several days.
Low level clouds and showers embedded on the trades will continue
to move from the east through early next week.

&&

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

Short term forecast still on track with the upper level ridge
weakening Friday into the upcoming weekend. At lower levels, a
surface high pressure to the northeast of the local area will
continue to yield ENE winds through the forecast cycle with patches
of moisture embedded on it. Although, the latest guidance continues
to suggest PW values remaining below normal, these patches of low
level moisture may briefly increase PW values near normal. Therfore,
still expect passing showers focused across the eastern third of
Puerto Rico as well as the US Virgin Islands early this morning.
There is a higher chance for shower activity Friday into the
upcoming weekend as the ridge aloft erodes, however, still expect a
seasonal weather pattern of passing showers across the eastern third
of Puerto Rico and the US Virgin Islands during the morning and
evening hours followed by some locally induced afternoon showers
across west Puerto Rico.

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

The upper level ridge is forecast to collapse by Sunday and a
strong west/northwest flow aloft is expected to remain over the
region through Wednesday. Low level moisture is expected to
increase slightly and better rainfall accumulations in diurnally
induced afternoon showers are expected over the islands through
early next week. During the second part of the workweek, an upper
level trough and a surface low are expected to move from the
western Atlantic to the north/northeast of the region. This will
increase instability and moisture pooling over the islands. If
forecast holds, moderate to locally heavy rainfall is possible
during the long term period.


&&

.AVIATION...VFR conditions are expected to prevail at all TAF sites
with -RA/VCSH at USVI terminals as well as JSJ through at least
31/14z. ENE winds near 10 knots to continue, becoming at around 12
knots with some sea breeze variations aft 31/12z.


&&

.MARINE...A 4 to 6 feet northerly swell will subside later tonight
across the Atlantic waters. Elsewhere, seas between 3 to 5 feet
are expected to continue for the next few days. Easterly winds
will continue between 10-15 knots, except across the northwestern
and southern coastal waters of Puerto Rico were winds up to 20
knots are expected. There is a high risk of rip currents along the
northern beaches of Puerto Rico and St. Croix.


&&

.FIRE WEATHER...Elevated fire weather conditions along the southern
coastal plains of Puerto Rico today. Please refer to the latest
fire weather forecast (FWFSJU) and fire danger statement (RFDSJU) for
more information.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 84 74 / 30 40 40 40
STT 84 73 83 72 / 20 40 40 40

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
450 AM AST Fri Feb 1 2019

SYNOPSIS...Ridge aloft is expected to erode as an upper level
trough moves north of the area. Trades will continue to prevail,
bringing patches of low level moisture at times. A somewhat
wetter pattern is possible by midweek the next week under
trofiness.

&&

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

GOES-16 water vapor shows low-level moisture currently moving across
the leeward Islands. This moisture will induce showers across the
U.S. Virgin Islands, and Puerto Rico this morning. Behind the
patch of moisture is a drier stable air mass which will limited
shower activity until later this afternoon.

Ridging at the surface and aloft will hold over the area through
late Sunday, and promote stable weather conditions through the short-
term period. Additionally, the ridges will continue to inhibit
vertical development of showers, therefore significant rainfall
amounts are not expected. Additionally, drier air in the mid to
upper levels will also hinder shower development across the region
today through Sunday. The high pressure is progged to push
shallow moisture across the U.S. Virgin Islands and Puerto Rico
over the next several days, which could lead to isolated to
scattered showers with light rainfall accumulations.

The mid and upper level ridge is expected to gradually weaken as the
through lifts off to the east to northeast, this will weaken the
strong inversion at 800 to 700 mb that has persisted through most of
the week. The weakening of the strong inversion could possible lead
to development of deep convection in the long-term period.

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

A mid to upper level trough is expected to dominate the local
weather regime by midweek the next week. As this feature moves away
Friday into the weekend, a ridge pattern aloft is then expected
to build from the west. At lower levels, a frontal boundary, which
is associated with the aformentioned upper level trough, will
approach the forecast area Wednesday afternoon while weakening.
Latest guidance suggested PW below normal values Mon-Tue with a
sharp increase Wed-Thu as the frontal boundary approaches the
local isles. Under this evolving pattern, expect a seasonal
weather pattern Mon-Tue with passing showers across coastal areas
in the morning and evening hours as well as a few locally induced
afternoon showers across west and northwest sections of Puerto
Rico. The chance for shower activity will increase Wed-Thu under
trofiness aloft and moisture advection. Confidence remains too low
to include thunderstorms in the long term forecast, but an isolated
thunderstorm cant be ruled out. A fair weather pattern is expected
once again by the end of the forecast cycle.

&&

.AVIATION...VRF conds will continue through 01/22Z TAF period with
iso to sct SHRA possible mainly across terminals TJSJ, TIST and
TISX until 01/12Z. ISO SHRA during the afternoon are possible
across terminals TJBQ and TJMZ due to diurnal effect until 01/22Z.
Sfc winds out of the east to northeast at 10 to 15 kts with high
gusts likely by 01/15Z. Wind turn to the north at 014 to 026 kft
ranging from 6 to 30 kts.

&&

.MARINE...A northerly swell will continue to slowly subside today.
Tranquil marine conditions are expected today and into the upcoming
weekend with seas below 5 feet and winds around 15 knots.

&&

.FIRE WEATHER...An elevated risk of fire weather conditions is
expected today across the southern plains of Puerto Rico, refer
to RFDSJU for details.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 74 83 73 / 40 40 30 40
STT 83 73 82 73 / 40 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Sat Feb 2 2019

.SYNOPSIS...A ridge aloft is expected to erode as an upper level
trough moves north of the area. Trade winds will continue to
prevail, bringing patches of low level moisture at times. A
somewhat wetter pattern is possible by midweek next week under
troughiness.

&&

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

Strong mid to upper level ridge just west of area and overhead
respectively, will maintain overall dry and stable conditions aloft
during the entire period. Surface high pressure ridge entering the
west and southwest Atlantic and weak trough across the west central
Atlantic will maintain light to moderate east to northeast wind flow
across the region through most of the weekend. Winds will however
become more east to southeast by late Sunday through Monday as the
surface high lifts east northeast into the north central Atlantic,
and a cold front with associated area of low pressure enters and
moves across the west Atlantic. This in turn will cause the local
pressure gradient to relax resulting an fairly light easterlies and
weak surface troughiness across the region.

Overall dry and stable weather pattern is expected to persist
through the weekend except for few early morning passing showers
followed by brief isolated to scattered afternoon showers over
portions of some islands and and the offshore coastal waters. Recent
model guidance and satellite imagery continued to suggest patches of
shallow moisture with embedded showers in the easterlies will
persist throught the period, but no significant rainfall
accumulations is anticipated. That said, overall fair weather skies
and mostly sunny conditions should prevail through Monday with a
shift in the easterly wind to a more southeast flow while becoming
light and variable by Monday. Afternoon convection if any should be
focused mainly over parts of the interior and west sections of
Puerto Rico and mostly down wind of the rest of the islands
including the U.S. Virgin islands where mostly sunny skies should
prevail each day.

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

Long term forecast still on track with a mid to upper level trough
prevailing across the local isles by Thursday afternoon. As the
trough moves away the upcoming weekend, a ridge pattern aloft is
then expected to build from the west. At lower levels, a frontal
boundary, which is associated with the aformentioned upper level
trough, will remain west of the forecast area but inducing a
surface trough across the northeast Caribbean Wed-Thu. This
feature will promote moisture advection early in the forecast
period.

Under this evolving pattern, expect a seasonal weather pattern
on Tuesday with passing showers across coastal areas in the
morning and evening hours as well as a few locally induced
afternoon showers across west and northwest sections of Puerto
Rico. The chance for shower activity will increase by midweek the
next week under troughiness aloft and moisture advection. Low
level moisture is then expected to erode the upcoming weekend
under building ridge. This will result in fair weather conditions
by the end of the forecast period.

&&

.AVIATION...VFR conds durg prd. SCT-BKN cld lyrs nr FL025...FL050
with SCT SHRA en route btw islands and over regional waters.
Isold SHRA reaching N and E coastal areas of TJSJ/TIST/TISX/TNCM/TKPK
til 02/14z. Brief Mtn Top obscr ovr E PR til 02/12Z due SHRA/LOW
CLDS. ISOLD-SCT SHRA psbl VCTY TJMZ/TJBQ 02/16Z-02/22Z. Sfc wnd
LGT/VRB bcmg fm E-NE btw 10-15 kts with higher gusts and sea
breeze variations aft 02/14Z.

&&

.MARINE...Tranquil marine conditions are expected to prevail
during the next several days with seas between 3 and 5 feet and
winds up to 15 knots. A moderate risk of rip currents is expected
across the north and some of the east facing beaches of the
islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 83 74 / 30 20 20 20
STT 82 73 82 73 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST Sun Feb 3 2019

.SYNOPSIS...Mid to upper level ridge extending across the region
will erode through Monday. A mid to upper level trough is then
expected to dominate the local weather regime by Thursday
afternoon, allowing moisture advection through Saturday.

&&

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

Mid to upper level ridge extending across the region will erode
through Monday as the subtropical jet rounds the base of a short
wave trough moving across the west Atlantic and just north of the
region today. This should slightly destabilize the upper levels and
weaken the trade wind cap inversion. Surface high pressure ridge
north of the region will shift eastwards into the central Atlantic
through Monday as a developing area of low pressure and associated
cold front moves across the west Atlantic. Local pressure gradient
is to then relax and induce a light east to southeast winds flow
and weak surface trough across the region by the middle of the
upcoming week.

Recent Satellite derived blended TPW as well as satellite imagery,
showed a slight increase in low level moisture transport in the
prevailing easterlies suggesting a better chance for chance for
passing showers during the rest of the morning hours mainly over the
coastal waters. Some showers may however brush the coastal areas
from time to time. For the rest of the day, still expect limited
moisture availability across the region, however the slight increase
in low level moisture transport today along with marginally unstable
conditions aloft may support some enhanced afternoon showers, mainly
over parts of the central and west sections of Puerto Rico. Activity
should however be of short duration. As a result, ponding of water
on roadways and in poor drainage areas will be possible with any
moderate to locally heavy rainfall.

For Monday and Tuesday...the prevailing light east to southeast wind
flow and limited moisture transport will bring more of the same
conditions with the chance of early morning passing showers in some
areas, followed by isolated to scattered afternoon showers during
the afternoons but mainly focused over the west and northwest
sections of Puerto Rico. Overall fair weather skies and mostly
sunny conditions should prevail through Tuesday with a shift to a
more southeast wind flow while becoming light and variable. For the
U.S Virgin Islands, a few passing early morning showers will be
possible with limited shower activity during the afternoons. The
showers should be mostly down wind and on the west end of the
islands as mostly sunny and fair weather skies should prevail.

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

A mid to upper level trough is expected to dominate the local
weather regime by Thursday afternoon, allowing moisture advection
through at least Saturday. Low level moisture is then expected to
erode Sunday into Monday as a mid level ridge builds across the
forecast area. At lower levels, a high pressure across the western
and central Atlantic is expected to strengthen, tightening the local
pressure gradient by the end of the forecast cycle.

Under this evolving pattern, expect a seasonal weather pattern on
Wednesday with passing showers across coastal areas in the morning
and evening hours as well as a few locally induced afternoon showers
across west and northwest sections of Puerto Rico. If the long term
forecast holds, the chance for shower activity will increase by the
end of the work week under troughiness aloft and moisture advection.
Confidence remains too low to include thunderstorms in the forecast,
but an isolated thunderstorms cant be ruled out, particularly Fri-
Sat. Fair weather and breezy conditions are expected by the end of
the forecast cycle under building ridge pattern and limited low
level moisture.

&&

.AVIATION...VFR conds thru fcst prd. Wdly scattered SHRA en route
btw islands and across local flying area til 03/14z. SCT ocnl BKn
lyrs nr FL025...FL040...FL080 Few tops nr FL100. Fm 03/16Z-03/22Z...
VCSH mainly at TJBQ/TJMZ. However, no sig operational wx impacts
anticipated at this time. Sfc wnds calm to LGT/VRB bcmg fm E 10-15
kts and occasionally higher gust and sea breeze variations aft
03/14Z.

&&

.MARINE...Tranquil marine conditions are expected to prevail
during the next several days with seas between 3 and 5 feet and
winds up to 15 knots. A moderate risk of rip currents is expected
across the north and some of the east facing beaches of the
islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 85 72 / 20 20 20 20
STT 82 71 84 72 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
430 AM AST Mon Feb 4 2019

.SYNOPSIS...
A weak mid to upper level ridge will relocate and hold across the
region today through Tuesday to promote dry and stable conditions
aloft. Surface high pressure ridge north of the region will shift
eastwards into the north central Atlantic, as a low pressure system
and associated cold front will develop and move across the west
Atlantic. This pattern will induce a weak surface trough and light
east to southeast winds across the region. Shallow moisture embedded
in the easterly trades will bring early morning passing showers to
the coastal waters and parts of the islands. Local sea breeze convergence
and diurnal effects will lead to afternoon showers of short duration
over parts of the islands.

&&

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

During the overnight and this morning shallow patches of moisture
moved over the U.S. Virgin Islands, and northern Puerto Rico. The
added moisture enhanced by the subtropical jet produced showers
across the U.S. Virgin Islands, and Puerto Rico, however due to the
showers fast forward speed rainfall amounts were light.

As the upper-level trough continues to move east of the area, weak
ridging at the mid to upper-levels reestablish itself through
Tuesday. An area of low pressure and associated cold front will
continue develop in the western Atlantic waters. The subtropical jet
will continue to stream over the region with winds ranging from 90
to 100 kts through early Tuesday, but the jet is progged to
intensify again on Wednesday as the polar trough continues to deepen
to the north. The destabilization of the upper-levels, as well as,
shallow moisture embedded in the easterly trades will help induce
showers across the U.S. Virgin Islands and eastern Puerto Rico
during the mornings, then across portions of interior and western
Puerto Rico during the afternoon.

The pattern with limited moisture in the mid to upper level of the
atmosphere still remains, as well as, strong inversion at the 820 mb
and up. These factors will inhibit the vertical growth of
convection, and make showers short-lived, with light rainfall
amounts. Late Tuesday into Wednesday an upper level trough will
develop north of Puerto Rico, and enhance instability, as well as,
pull low-level moisture from a stalled trough in the central
Atlantic over the region. In addition, the subtropical jet will also
intensify late Tuesday into Wednesday which will aid in upper-level
instability.

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

A mid to upper level trough is expected to develop and dominate
the local weather regime by Thursday. This will favor an increase
in moisture advection through at least early Saturday. Low level
moisture is then expected to erode late Saturday through Sunday and
into the early part of the following week, as a mid to upper level
level ridge is forecast to build once again across the forecast
area. At lower levels, a high pressure across the western and central
Atlantic is also expected to strengthen, tightening the local pressure
gradient and consequently increasing the east to northeast trade winds.

Under this expected pattern, expect an overall increase in moisture
convergence across the region Thursday through Friday and possibly
into Saturday, with a gradual improvement over the weekend and into
the following week. Therefore, the chance for shower development
will increase by the end of the work week under influence of the
trough aloft and moisture advection. Confidence however still remains
low to include thunderstorms in the forecast at this time, but an
isolated thunderstorms can`t be ruled out, particularly Friday-
early Saturday. A return of fair weather and breezy conditions are
expected by Sunday and the end of the forecast cycle under building
ridge pattern and limited low level moisture.

&&

.AVIATION...Mainly VFR conditions will continue to prevail across
all terminals through 05/00Z. VCSH/SHRA are forecast across terminals
TJBQ, and TJMZ by 04/18Z with clearing conditions by 05/01Z. Surface
winds will continue from the east between 10-15 kt, however light
and variable winds are expected by 05/03Z. L/lvl wnds fm the E-NE
10-15 kts blo FL100...then backing fm W-NW and incr w/ht to Max
wnd btw 80-100 kts nr FL350.

&&

.MARINE....Seas up to 5 feet expected today, especially across
the offshore waters and 4 feet or less nearshore. Winds from the
east to southeast 5 to 15 knots expected today under fairly
tranquil seas.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
518 AM AST Tue Feb 5 2019

.SYNOPSIS...An inverted surface trough will bring better chances
for showers on the windward side of the islands tonight. Then increasing
moisture and a cut-off low at mid levels dropping south over the
eastern tip of the Dominican Republic will bring increasing
chances for rain this week. Conditions will dry at mid levels on
Saturday and Sunday, but showers will continue as patches of low-
level moisture continue to move through and winds increase early
next week.

&&

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

Today a surface trough currently west of the Leeward Islands will
continue to move to the west, and affect the U.S. Virgin Islands,
and Puerto Rico later this afternoon. This feature will bring
shallow moisture from the east, which will aid in the development of
afternoon showers. However, a strong inversion remains around 750 mb
which will inhibit deep convection from forming. Additionally, weak
0 to 3 km steering flow will cause showers that develop to linger in
place which could cause urban and small stream flooding in some
areas. Later today the trough will begin to impinge on and weaken
the mid and upper level ridge over the region. As a result the
ridges will shift to the east of the area, which will allow
moisture from the stalled out front in the central Atlantic to
filter in from the east late Wednesday through Friday.

A deepening low and its associated trough will continue to move into
the central Atlantic waters over the next several days before
stalling north of Puerto Rico later this week. This trough will
cause unstable conditions, and increase upper-level instability by the
middle of the week therefore thunderstorms were put into the grids
for Thursday afternoon. Additionally, the trough will be negatively
titled, and 500 mb temperature will be minus 10 degrees Celsius
these factors are good indicators of unstable conditions.

At 500 mb a low begins to develop on Wednesday and deepens, then
becomes cut-off from the main flow late Wednesday into early
Thursday morning over Hispaniola, west of Puerto Rico. The cut-
off low is expected to weaken the trade wind cap, late Wednesday
into Thursday. Moisture is expected to increase as well as rain
chances.

.LONG TERM...Friday through Tuesday...
The upper level trough that was approaching the area Wednesday and
Thursday will arrive on Friday. This will also be the peak of the
moisture with a band in the mid and lower levels. This moisture
will increase the shower activity early Friday and during the day.
The cold mid-level temperatures (as low as minus 12 degrees
Celsius) will also keep unstable conditions in the area on Friday.
While there is a slight possibility that isolated thunderstorms
could occur overnight Thursday and early Friday morning anywhere
in the forecast area, they were only included in the forecast in
western Puerto Rico during the afternoon hours where instability
will be the greatest. Moisture slowly diminishes on Saturday. Then
much drier air at 700 mb moves into the forecast area on Sunday
with POPs diminishing each day. Wind increase considerably late in
the weekend and early next week. With 500 mb winds caught between
the retreating low pressure to the east and an intruding high
from the west, east winds at 500 mb could accelerate to as much as
45 knots and will add some momentum to the lower level winds next
week.


&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals through the forecast period. However, SHRA/VCSH are
forecast to develop by 05/15Z across terminals TJSJ, and then move
to terminals TJMZ and TJBQ by 04/17Z with rain diminishing by
05/01Z. Currently sfc winds are light and variable, but winds are
forecast to increase to 5 to 15 kts by 05/14Z. Maximum winds W
70-80 kts btwn FL340-440.


&&

.MARINE...Marine conditions remain mostly tranquil with a moderate
risk of rip currents on the northern coasts of Puerto Rico,
Culebra and Saint Croix. Seas will begin to rise with a northerly
swell on Sunday and Monday, with winds increasing considerably
early next week. At this time small craft advisories are possible
in the Caribbean on Saturday and in the Atlantic by Monday and
continuing into the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 84 74 / 50 40 30 40
STT 83 73 83 72 / 30 30 30 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Wed Feb 6 2019

.SYNOPSIS...A weak inverted trough at the surface will move
through the area today and tonight, followed by a 700 mb low
passage on Thursday. Drier air will move in from the northeast
Saturday night and Sunday, but shallow moisture will maintain
brief passing showers on the windward side of Puerto Rico and
around the U.S. Virgin Islands through mid week next week.

&&

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

A mid level trough will continue to deepen across the western
Atlantic over the next several days before stalling east of Puerto
Rico. Moisture from the front will be pulled across the region
late Wednesday into early Thursday by high pressure positioned in
the northeastern Atlantic through Friday. Puerto Rico is progged
to be in the base of the trough late Thursday into early Friday
morning.

At 500 mb recent guidance no longer has a low closing off to the
west or near Puerto Rico late Wednesday. Instead it shows a
deepening trough that will continue to progress southeast of
Puerto Rico, with a cut-off low developing northeast of the area
Friday afternoon into Saturday. The change in location of the 500
mb cut-off low, as well as the upper-level trough will shift the
more unstable conditions to the north and east of Puerto Rico.
However, as a result of the proximity of the trough to the island,
and strong subtropical jet as well as increase in low-level
moisture conditions will still be unstable.

Today an inverted trough at the surface currently, over the U.S.
Virgin Islands will bring shallow moisture across eastern and
northern Puerto Rico this morning. This added moisture will help
induce isolated to scattered showers over eastern and northern
Puerto Rico, then continue to traverse to the west. A strong low-
level jet of 80 kts will continue across the region today, this
along with local and diurnal effects will induce showers across
interior and western Puerto Rico this afternoon. Showers that
develop are expected to move slowly as a result of light 0 to 3 km
steering flow; this could lead to urban and small stream flooding
for areas that receive persistent shower development.

Early Thursday through Friday rain chances will increase as low-
level moisture and instability increases. This will add in the
development of scattered showers across the U.S. Virgin Islands, and
eastern half of Puerto Rico during the morning hours, then moving to
the interior and western areas during the afternoon. Unstable
conditions are still expected, but due to the 500 mb low cutting off
to the northeast of the Puerto; this will shift the better dynamics
northeast of the area. At this time its we will wait until
guidance comes into better agreement on the positioning of the
low before we remove thunderstorms from the forecast.

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

The jet over the area will move into the tropical Atlantic by
Saturday, and by Saturday, the shortwave trough at the upper
levels will also have passed through the area. Mid-level moisture
is also gone by Friday. This will leave shallow shower activity.
When a strong high pressure at the surface exits the coast of the
eastern United States gradients over the area will increase and
bring stronger east northeast winds. Those winds will also carry
shallow patches of moisture that will experience sharp lifting
when they reach island terrain so that brief passing showers on
the windward side of the islands will continue through the period.
By the end of the period winds will become more east southeast.
Maximum temperatures on the northeast coast will then rise
slightly and shower chances will taper off.

&&

.AVIATION...Mainly VFR conditions are expected across all terminals,
however vcsh/shra could cause some eastern terminals to briefly fall
to MVFR conds. SHRA will increase across terminals TJBQ, TJMZ and
TJSJ by 06/15Z before diminishing by 07/02Z. Winds will be out of
the east to northeast at 5 to 10 mph, winds are expected to
become light and variable by 07/00Z across most of the terminal
sites. Winds aloft turn to the west and west northwest btwn
FL190-440 with winds ranging from 20 to 80 kts. Max winds at
FL360. Some mid level AC between FL070-080 will move across the
area this morning.

&&

.MARINE...Seas are rather tranquil for the next several days, but
increasing winds over the weekend and some limited swell action
will generate 7 or 8 foot seas by Monday--mainly in the Atlantic
with some of the Caribbean affected as well.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 72 84 73 / 30 40 50 50
STT 83 71 83 72 / 30 50 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
525 AM AST Thu Feb 7 2019

.SYNOPSIS...Weak features transiting Puerto Rico and the U.S.
Virgin Islands, and showers due to convergence in a band of
moisture that is stalled over the area, will continue through
Sunday in our typical diurnal pattern. Although dry slots are
embedded in this pattern, moisture fluctuates in a narrow range
throughout the next 5 to 7 days.

&&

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

Showers continue to develop this morning across the northwestern
areas of Puerto Rico, and the inner coastal waters. The shower
development is a result of a trough to the east of Puerto Rico
converging with a weak boundary to the northwest of the island.
Showers are expected to continue through the afternoon hours and
spread south over western Puerto Rico, but not over the southern
areas of Puerto Rico. The boundary northwest of Puerto Rico will
continue to weaken before dissipating later today. The boundary
weakens as a result of the surface and mid level ridges extending
across Hispaniola, and creating subsidence or sinking air over
the area.

Later today, the surface trough east of Puerto Rico will become
the dominant feature over the area. The high in the northeast
Atlantic will push moisture from the trough in the central
Atlantic over the U.S. Virgin Islands, and most of Puerto Rico
this afternoon. The added moisture, as well as the east to
northeast winds, will help induce showers this afternoon. Similar
to previous days, light low-level winds could cause showers to
linger over the same areas today, leading to localized urban and
small stream flooding.

However, analysis of the GFS 850 mb relative humidities show a
patch of values around 30 to 40 percent moving into eastern
Puerto Rico from the southeast this morning. These lower relative
humidities should limit the development of showers across the
area this morning. Additionally, if moisture from the deepening
trough moves further northeast than expected, this could cause
POPs to be lower today.

Another low-level trough will bring moisture back west out of the
low developing in the trough to our northeast. The 500 mb ridge
across the eastern Atlantic will help push this moisture across
the region again on Friday. Friday will be the best day for
showers and isolated thunderstorms, due to an increase in low-
level moisture and mid-level instability in the cold pool
associated with the 500 mb low. This coincides with the backing
of winds with height at the mid-levels of the atmosphere, and 500
mb temperatures of minus 12 degrees celsius.

Saturday, residual moisture will linger across the U.S. Virgin
Islands and Puerto Rico. This moisture will cause scattered
showers during the early morning across eastern and northern areas
of Puerto Rico, and the U.S. Virgin Islands. Then typical daytime
shower activity during the afternoon for the region will ensue.

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

Earlier models showed moisture near the top of the low-level
atmosphere diminishing in northeast flow, and this is still the
case, but the drying is not nearly as intense as depicted in model
runs one and two days ago for late Saturday and Sunday. On Monday
and Tuesday this same flow turns east southeast and drags moisture
back over the area--first in patches and then in a more solid
stream. The center of this stream, however appears to focus more
on Hispaniola by Wednesday and Thursday. Nevertheless, the drying
promised will still be ameliorated by brief passing showers each
day on the windward slopes of Puerto Rico during the late night
and early morning hours followed by mid-afternoon convergence in
western Puerto Rico.

After the upper level trough passage late Friday, high pressure
at 250 mb builds over the southeastern Caribbean and continues
through much of the week. With high pressure moving in at mid
levels under this upper level ridging, moisture levels at both mid
and upper levels remain extremely dry throughout--and even
beyond--the long term period.

&&

.AVIATION...Brief MVRF conds are psbl across terminals TIST,
TISX, TNCM. Then, aft 07/12Z VRF conds will prevail across all
terminals through 08/00Z. Afternoon showers will develop across
TJMZ, AND TJMZ with mtn obscurations. SHRA will decrease by 8/02Z.
Winds will be out of the east to northeast at 5 to 10 kts, then
winds will become light and variable by 08/02Z.

&&

.MARINE...Seas increase slowly Friday through Sunday and then
become hazardous early in the week. Small craft advisories will
be needed Monday or Tuesday with a concurrent rise in the risk of
rip currents on the coasts with northern exposures.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 84 72 / 40 50 50 60
STT 83 74 84 73 / 40 50 50 40

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
544 AM AST Fri Feb 8 2019

.SYNOPSIS...Bands of moisture are streaming across the forecast
area with mostly isolated or scattered areas of showers running
parallel to the front northwest of the area. Drier air will
slowly move into the area as high pressure in the mid and upper
layers takes better control through Tuesday. At the surface, winds
will continue to increase through Monday.

&&

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

This morning a few passing showers embedded in the trade winds
moved across eastern and northern areas of Puerto Rico with light
rainfall amounts.

Analysis of the 250 mb wind speeds and heights shows an upper-
level jet to the east of Puerto Rico. This jet will aid in the
development of showers today. Currently Puerto Rico is in the
base of the 500 mb and 250 mb troughs. These troughs extends
across the central Atlantic waters. The 500 mb and 250 mb troughs
will continue to weaken and lift to the northeast over the next
several days. The weakening is a result of the upper and mid-level
ridges that will build into the region from the west today
through the weekend. However, the moisture associated with the
troughs will be pushed by the easterly flow at lower levels across
the U.S. Virgin Islands, and Puerto Rico today and Saturday by
the surface ridge in the far eastern Atlantic. Therefore,
scattered showers are expected across the U.S. Virgin Islands, and
Puerto Rico during the early mornings, then showers will develop
across the interior and western areas during the afternoon.
Thunderstorms have been removed in spite of the 500 mb
temperatures reaching minus 12 degrees near San Juan since
moisture will not be seen in the quantities expected by previous
model runs and mid levels will be extremely dry.

Early Saturday into Sunday the ridges at the surface and aloft will
re-establish themselves across Puerto Rico through the remainder
of the short-term period. The ridging will create fair weather,
and a strong trade wind cap across the region. This will limit
vertical development of showers during the weekend. However, brief
scattered showers are possible during the afternoon.

.LONG TERM...Monday through Friday...
By Monday the mid-level ridge will be pretty squarely north of
the area and the upper level ridge will extend from South America
north northwest across the forecast area. This will cause some
drop in the precipitable water values Monday and Tuesday, but also
moisture is eroded from the top of the lower layer between 600
and 700 mb, with a minimum of moisture being reached on Tuesday
night. The upper level ridge then begins edging east, until by
Friday the area is set up for another trough passage from the west both
at mid and upper levels. In fact, mid level moisture does not
return again until Friday afternoon. Since low level moisture is
always present in bands and patches, scattered showers in the
typical a wintertime diurnal pattern will continue with night and
early morning showers on the windward side of Puerto Rico and
occasionally over the U.S. Virgin Islands. Then during the
afternoons scattered showers are expected in western Puerto Rico.

&&

.AVIATION...VFR conditions are expected to prevail across all
terminals through the remainder of the TAF period. The forecast
period. Afternoon showers will develop across TJMZ, AND TJBQ with
mtn obscurations. SHRA are forecast to decrease by 09/23Z. Sfc
winds out of the east to northeast at 5 to 10 kts. West winds
aloft reached 90 knots at FL330 at 07/12Z. They will drop off to
less than 35 knots by 08/15Z.

&&

.MARINE...Surface winds will gradually increase today through
Tuesday. By Monday winds of 15 to 20 knots will be fairly
commonplace in the outer waters and funnel areas around Puerto
Rico. Seas will respond accordingly and by Monday 7 foot seas
will be seen in the outer Caribbean and Atlantic waters. Northerly
swell will add to the hazardous nature of the seas through at
least Wednesday.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
453 AM AST Sat Feb 9 2019

.SYNOPSIS..Trade wind showers will continue through the weekend.
Winds will increase slowly through the weekend and early next week
such that conditions will become breezy with frequent showers
next week over many parts of Puerto Rico and the U.S. Virgin
Islands.

&&

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

A mid level trough located just east of the leeward islands is
inducing a weak surface trough that will move through the area
during the day today. This will result in variable weather
conditions with brief trade wind showers moving across the local
waters and affecting portions of the islands from time to time.
Scattered showers are expected to affect the northern and eastern
half of Puerto Rico and the USVI during the morning hours and
across southwest PR during the afternoon hours due to daytime
heating and local effects. Additional brief showers are likely
across the rest of PR and the USVI during the afternoon hours. The
main hazard from these showers should be limited to ponding of
water on roadways and in poor-drainage areas.

On Sunday and Monday, a mid to upper-level ridge will move overhead.
This will result in stable conditions aloft with no deep convection
expected. At the surface, a high pressure will be moving from the
east coast of the United States into the western Atlantic. This
will tighten the local pressure gradient and result in breezy
conditions as the low-level flow increases to 15-20kts. The
increased low-level flow will also bring fragments of low-level
moisture across the local area, resulting in occasional passing
trade wind showers.

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

By Tuesday the upper level ridge will extend north northwest
directly over the forecast area. It will move slowly east
Wednesday and Thursday, and, as it does, a sub-equatorial jet
will increase over Puerto Rico and the U.S. Virgin Islands to as
much as 80 knots Thursday night. A weak short-wave trough moves
over the area (again at upper levels) on Friday to enhance shower
activity.

At mid levels high pressure north of the area early Tuesday will
move east. This will allow a weak short wave rough to move through
on Friday with colder 500 mb temperatures--this time to around
minus 7 degrees Celsius. High pressure at mid levels moves in
from the west on Saturday.

At lower levels moisture bands will continue to float through on
the flow around a high pressure northeast of the area. Winds at
lower levels should peak on Tuesday and Wednesday, with 850 mb
winds running between 20-30 knots. This will intensify the showers
against the higher terrain of Puerto Rico, but even though showers
will be numerous on the windward slopes and coasts of the island, amounts
will still remain limited due to the rapid movement of the
showers and the shallow moisture whose tops will range from 10-15
kft. Although the GFS has reduced the intensity of the last and
best band of moisture on Friday, it still suggests another round
of 1.5 inches of precipitable water Friday through Saturday
morning. Moisture decreases all day Saturday and Saturday night.
Low level flow is easterly on Tuesday of this week and becomes
east southeast the rest of the week. This will favor showers over
the southeast portion of Puerto Rico during the overnight and
morning hours and additionally over the northwest sections in the
afternoons. Scattered showers will be the rule over the U.S.
Virgin Islands, but amounts will be quite light.

&&

.AVIATION...Mainly VFR conditions are expected across all terminal
sites thru the fcst period. Periods of passing SHRA are expected
across most of the region today, resulting in VCSH across most of
the terminals. Winds will continue from the ENE to NE at less
than 10 kts through 09/13z, before increasing to around 15 kts
afterwards with some sea breeze variations and hir gusts. Mtn
obscurations in hir trrn of PR. Max winds WNW 35-45 kt btwn
FL340-480, bcmg by 10/00Z NE 35-45 kt btwn FL210-280.

&&

.MARINE...Winds have been increasing for the last 24 to 36 hours
and will continue to increase to 15 to 20 knots over the weekend
with a few areas seeing 20-22 knots and higher gusts. This will
cause seas in exposed areas to increase to 6 to 8 feet--with the
highest seas expected early Tuesday afternoon. Small craft
advisories will be going up on Monday--mainly for seas in the
local waters of unprotected areas.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 83 73 / 70 50 50 50
STT 84 73 82 73 / 50 50 40 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
507 AM AST Sun Feb 10 2019

.SYNOPSIS...High pressure crossing the Atlantic to the north will
maintain trade winds that carry bands of moisture and showers
across the U.S. Virgin Islands and Puerto Rico through the week.
Flow will be more southeasterly at the surface Wednesday through
Saturday.

&&

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

Mid to upper-level ridge will build across the area through early
next week to result in stable conditions aloft, with no deep
convection expected. Meanwhile, at the surface, a strong high
pressure will be moving off the east coast of the United States into
the western Atlantic later today through Monday. This will tighten
the local pressure gradient, resulting in breezy conditions with the
surface flow increasing to between 15 and 20 kts from the east
northeast. The increase in the low-level flow will also cause an
increase in the frequency of the trade wind showers through
Monday. Showers are expected across the northern and eastern half
of PR during the overnight and morning hours. This will be
followed by limited activity across western PR during the
afternoon hours. Given the fast moving nature of these showers,
rainfall accumulations for the most part should remain on the
light side.

On Tuesday, current model guidance is indicating that a drier than
normal air mass will be moving across the area. This will produce
mainly fair weather conditions across the region with some but very
limited shower activity expected. Tuesday also seems to be the day
that the winds peak, as the current forecast soundings show the 0
to 3 km flow increasing to as high as 20-24 kts. As the surface
high pressure moves farther eastward into the central Atlantic,
winds will also become more east southeast.

.LONG TERM...Wednesday through Sunday

By Wednesday the upper level ridge that will extend north
northwest out of South America will begin edging east of Puerto
Rico and the sub-equatorial jet will begin increasing in strength
over the area. On Thursday night winds will diminish and a weak
upper level trough will pass to the north of the area followed by
ridging that will build in place during the rest of the period.

At mid levels, the high pressure ridge is centered over 60 west
but dominates the eastern Caribbean. It continues east into the
tropical Atlantic, but the trough that follows Friday and Saturday
is very weak--barely a break in the high pressure. The high
pressure returns on Saturday. Mid levels and upper levels are
almost completely dry during the long term period, with moisture
barely reaching 700 mb Saturday.

At lower levels, flow will turn almost completely southeast
Wednesday. 850 mb flow will carry bands of wet and dry air that
will pass through the area. So, showers will move across Puerto
Rico and the U.S. Virgin Islands from time to time and some
showers will develop in northwest Puerto Rico during each
afternoon. Flow becomes more easterly on Sunday. Amounts will
generally be light, but some areas will see a few heavier showers
able to create ponding on roadways and poorly drained areas.

&&

.AVIATION...Prevailing VFR conditions are expected across all
terminal sites through the forecast period. Trade wind showers will
continue to result in VCSH, mainly across TJSJ, TIST, TJBQ through
10/12Z. VCSH expected after 10/16z across TJMZ and TJPS. Low-
level winds will continue from the ENE at less than 10 kts through
10/13z, increasing to around 15 kts with higher gusts and some
sea breeze variation afterwards.


&&

.MARINE...As high pressure spills off the eastern coast of the
United States, winds are increasing and seas are responding.
Mariners will need to exercise caution in a number of areas today
through Monday in the Atlantic and the Caribbean. Small craft
advisories will need to go up on Monday night as seas reach 7
feet. Conditions will improve on Thursday, although seas will
still be close to 7 feet in the far northeast corner of the
forecast area.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 83 73 / 50 40 40 40
STT 82 73 85 72 / 50 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST Mon Feb 11 2019

.SYNOPSIS...Surface high pressure moving across the western
Atlantic will result in breezy conditions through midweek.
Fragments of low-level moisture embedded within the trade wind
flow will continue to result in occasional trade wind showers. A
mid to upper-level trough will move near the region by the end of
the work week into early next weekend, resulting in an increase in
moisture and showers. A return to a fair weather pattern is
expected by late next weekend through early the following week as
another mid to upper-level ridge builds overhead.

&&

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

A strong surface high pressure over the western Atlantic will cause
breeze east to east-northeast trades through at least Tuesday across
the region. Sustained winds between 15-20 mph with higher gusts are
expected during this period. A cold front is expected to stall
around 24N during the next day or so with no significant impact on
the local weather conditions. The surface high will shift into the
north central Atlantic by Wednesday and winds will turn more from
the east-southeast, but moderate to locally fresh trades will
prevail through the short term period. At upper levels, a ridge is
forecast to build over the region from southwestern Atlantic into
the northeastern Caribbean, keeping a fairly stable atmosphere
through at least Wednesday. Therefore, shower activity will be
limited to trade wind showers across the USVI and PR through the
short term period. Hi res models suggest best rainfall amounts
between the west coast of PR and the Mona Passage today and from an
area of scattered showers that was moving from the Leeward islands
into the USVI earlier this morning.

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

The mid to upper-level ridge axis will shift eastward as a mid to
upper-level shortwave trough approaches from the west later
Thursday into the day on Friday. At the lower-levels, the flow
will be completely from the southeast as a frontal system moves
across the western and central Atlantic. The low-level flow from
the southeast will increase the low-level moisture transport.
Therefore, an increase in shower activity can be expected across
the area Friday and Saturday. At this point, confidence is low on
how much rainfall can be expected as it will all depend on how much
moisture will be available and where the best upper-level forcing
sets up.

By Sunday, as the mid to upper-level trough moves away and
weakens, another mid to upper ridge will rapidly build across the
region and hold through at least the first part of the following week.
Therefore, a return to a fair weather pattern with limited shower
activity can be expected.

&&

.AVIATION...Mainly VFR conditions are expected to prevail during the
next 24 hours across all terminals. However, trade wind showers
could result in tempo MVFR cigs at TNCM/TIST/TISX through Monday
morning. SHRA over western PR could also cause tempo MVFR cigs at
TJMZ btw 16z-22z. East winds will prevail at 15-20 kt with higher
gusts after 14z.

&&

.MARINE...A surface high pressure moving across the western
Atlantic will to continue to build north of the region and
tighten the local pressure gradient, resulting in moderate to
fresh easterly trade winds between 15 and 20 knots. This will
create choppy and hazardous marine conditions across most of the
regional waters through mid week with seas ranging between 5 and 8
feet. Therefore, small craft advisories are in effect. Along with
the hazardous seas, a high risk of rip currents is in effect for
the north facing beaches of PR, Culebra, and Saint Croix and for
the north facing beaches of Saint Thomas starting tonight.

&&

FIRE WEATHER...Even though some showers occurred across the
southern coastal plains and the western foothills of Puerto Rico
on Sunday, not enough rain has fallen to significantly change the
vegetation state. Given that the flow will continue from the east
northeast today with winds increasing to between 15 and 20 mph
with higher gusts, relative humidity values are likely to drop
into the mid 40s for a couple of hours during the late morning
into the early afternoon hours. Therefore, the fire danger threat
will remain elevated and a fire weather discussion (RFDSJU) has
been issued for the southern coastal plains as well as the western
foothills of Puerto Rico.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 85 72 / 40 40 10 10
STT 83 73 84 73 / 50 40 20 40

[cycloneye]

AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
532 AM AST Tue Feb 12 2019

.SYNOPSIS...Ridge aloft will continue to hold through Wednesday.
A broad surface high pressure north of the region will move
further into the central Atlantic during the next couple of days.
This will push trade wind showers and low level cloudiness through
the short term period. However, overall fair weather conditions
should prevail. An upper level trough is forecast to move over
the region later in the week into the weekend, increasing shower
activity across the islands.

&&

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

Upper level ridge will dominate over the local area today and
Wednesday but an upper trough will start digging west of the local
islands on Thursday and its axis will be just west of Hispaniola by
Thursday evening. Strong surface high pressure across the central
Atlantic will dominate the local wind flow, which will be moderate
and easterly today but will gradually become southeasterly by
Thursday. As far as rainfall for the next few days, passing
scattered showers will move in during the overnight and morning
hours, which may affect the USVI and eastern PR particularly with
the patches of moisture that move in. In the afternoon hours, the
local effects and diurnal heating may cause some showers to develop
across portions of central and western PR as well as the westernmost
tip of the USVI. That said, the latest high resolution guidance has
very little rain developing due to local effects, perhaps it is
because the mid levels are expected to be rather dry and there will
be a strong cap inversion, as indicated by the forecast soundings.
So the bottom line is that isolated to scattered but brief showers
are to be expected across the local waters, USVI and portions of PR.
Slightly higher moisture on Wednesday may cause numerous showers
near the USVI and across eastern PR.

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

A mid to upper level trough is forecast to move over the region
between Friday and Saturday. Meanwhile the upper ridge moves
further into the central Atlantic as well as the surface high.
Winds are expected to diminish and turn more from the
south/southeast during the end of week. Low level moisture and
instability aloft will gradually increase from Friday through
early Sunday. Therefore, scattered to locally numerous afternoon
showers are expected to develop at least on Friday and Saturday
over portions of the interior and northwestern Puerto Rico.
Followed by scattered showers across the local waters and over
portions of the USVI and the eastern sections of PR. Elsewhere,
isolated to scattered showers in diurnally induced convection is
expected. Another upper level ridge and surface high pressure are
forecast to build over and to the north of the region through next
week. This will increase winds and trade wind shower activity
once again across the forecast area.


&&

.AVIATION...VFR conds are expected for the next 24 hours. However,
SCT SHRA are expected and will cause VCSH across the USVI and PR
terminals today. East winds of 5-10KT expected through 12/13Z,
increasing to 10-20KT thereafter and for most of the day. Winds will
diminish again after 12/23Z.


&&

.MARINE...Wind driven seas and a northerly swell are creating
hazardous marine conditions across most of the regional waters.
Seas are expected to range overall between 5-8 feet and easterly
winds will continue between 15-20 knots with higher gusts through
the day. Small craft advisories are in effect through midweek,
please refer to the latest marine weather message (MWWSJU) for
more information.

For beach goers, life threatening rip currents are expected to
continue along the north and east facing beaches of the islands
through at least Wednesday. For detailed information please refer
to the latest coastal hazard message (CFWSJU) and surf zone
forecast (SRFSJU).


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 86 73 / 40 40 50 50
STT 84 73 84 73 / 30 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
510 AM AST Wed Feb 13 2019

.SYNOPSIS...Mid level ridge and surface high pressure will move
northeast of the region today. East to southeast winds will
prevail for the next several days. Fair weather conditions are
expected to prevail through at least Thursday. Moisture and
instability increases early in the weekend as an upper level
trough moves over the region.


&&

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

Upper level ridge will dominate over the local area today but an
upper trough still looks like it will start digging to the west of
the local islands and its axis will be just west of Hispaniola by
Thursday evening, then over Hispaniola by Friday afternoon. Strong
surface high pressure across the central Atlantic will dominate the
local wind flow today, which will be moderate and east southeasterly
as it gradually becomes southeasterly by Thursday due to a
developing surface low pressure across the western Atlantic and the
surface high moves east. As far as rainfall for the next few days,
the latest guidance keeps suggesting passing isolated to scattered
showers, which may affect the USVI and eastern PR. However, compared
to the model runs seen yesterday, the latest guidance backed off
even more for the expected rainfall today and Thursday as the
available moisture appears to be less than previously forecast by
the models. In the afternoon hours, the local effects and diurnal
heating may still cause some showers to develop across portions of
central and western PR as well as the westernmost tip of the USVI,
but again, the rainfall totals should be minimal. The mid levels are
still expected to be fairly dry and there will be a strong cap
inversion today and Thursday, as indicated by the forecast
soundings, but this cap and a moistening of the mid levels is
forecast for Friday. In addition, the upper trough may be in a
better placement on Friday to give us a better chance of rain. In
general, isolated to scattered but brief showers are to be expected
across the local waters, USVI and portions of PR today and Thursday.
Higher moisture on Friday and upper trough over Hispaniola may cause
an increase in shower activity over the local area.

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

A mid to upper level trough is forecast to move over the region
on Saturday. Increasing instability and the potential for
moderate to locally heavy rainfall in afternoon convection over
the northwestern quadrant of Puerto Rico. Winds are expected to
diminish and turn more southerly through the weekend. This will
result in warmer temperatures across the islands. Pooling of low
level moisture over the forecast area is expected through Sunday
and scattered showers with periods of moderate rainfall are
possible across the regional waters as well across the USVI and
across portions of PR between Saturday night and early Sunday
morning.

A surface high pressure is forecast to build just north of the
area by Monday and easterly trades are expected to prevail during
the workweek. An upper level ridge is forecast to build over the
southwestern Atlantic and across the Caribbean Sea through next
week. This will promote stable conditions once again and limit
shower activity to passing trade wind showers across the forecast
area and shallow afternoon convection over western PR. Streamers
should develop off the USVI but rainfall amounts are expected to
be minimal.


&&

.AVIATION...VFR conds are expected for the next 24 hours. However,
ISOLD/SCT SHRA expected and may cause VCSH across the USVI and PR
terminals today. ESE winds of 10-15KT with occasional gusts expected
today. Winds will diminish again after 13/23Z.


&&

.MARINE...Choppy seas up to 7 feet are expected to continue today
across most of the regional waters. Small craft advisories are in
effect through this evening for the near shore waters and through
the end of the week for the offshore Atlantic and Anegada
Passage. As winds decrease during the next few days, marine
conditions will gradually improve through the end of the
workweek. There is a high rip current risk in effect for the
northern beaches of PR, Culebra and St. Thomas.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 73 88 74 / 30 30 20 20
STT 85 74 85 74 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
455 AM AST Thu Feb 14 2019

.SYNOPSIS...Surface high pressure will move east across the
central Atlantic while a surface low develops across the western
Atlantic, which will dissipate on Saturday. This setup will keep a
southeastern wind flow as it weakens this weekend. Upper trough
will move through the local islands on Friday and Saturday,
increasing the local instability mainly on Saturday.

&&

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

An upper level trough over the southwestern Atlantic and an
associated surface front will gradually increase instability over
the region through the short term period. Particularly on Friday and
Saturday. A moist southerly wind flow is expected across the region
as the surface front is forecast to remain over the open Atlantic
waters and a surface high pressure shifts further into the central
Atlantic. Therefore, afternoon showers are expected to develop
mainly over portions of the interior and northwest quadrant of
Puerto Rico. Some of these showers could be heavy at times and
ponding of water in low lying areas are possible this afternoon. The
potential for localized urban and small stream flooding increases on
Friday and Saturday afternoon over the same areas. Across the U.S.
Virgin Islands, fair weather conditions are expected today and on
Friday but isolated showers can`t be ruled out at times. Showers are
expected to increase in coverage on Saturday as the upper level
trough moves over the area.

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

The available moisture will be near to slightly above normal on
Sunday and Monday but the mid and upper levels will have a high
pressure and therefore not conducive for significant rainfall
development across the local islands. Thereafter, mainly dry air
with patches of moisture moving in, which would cause brief
isolated to scattered showers in the evening and morning hours
with a slight chance of showers developing in the afternoon across
western PR since the mid to upper high pressures are still
forecast to prevail in the long term. So the bottom line is that
fairly benign weather is expected in the long term range.

&&

.AVIATION...Mainly VFR conditions are expected to prevail during the
next 24 hours across all terminals. However, SHRA over northwest PR
could cause tempo MVFR cigs at TJBQ btw 16z-22z. ESE winds around 15
knots are expected with sea breeze variations after 14z across the
northwest coast of PR.

&&

.MARINE...Seas across the offshore Atlantic waters will continue
to be hazardous, up to 7 feet, while the nearshore Atlantic waters
and local passages will have seas up to 6 feet. There is a
moderate risk of rip currents across many of the local beaches,
but the high risk was cancelled. Slow and gradual improvement of
the seas is expected through the next few days.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 74 87 73 / 20 30 30 30
STT 84 77 83 75 / 20 40 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
456 AM AST Fri Feb 15 2019

.SYNOPSIS...Surface high pressure across the east central Atlantic
and a surface low pressure in the western Atlantic will keep a
moderate to fresh southeasterly wind flow today and Saturday
across the local area. Thereafter the local wind flow will
gradually become more easterly. Mid and upper level trough is
still expected to dig just west of the local islands and move
through the islands this weekend. Near normal to higher than
normal moisture expected through late Sunday night. A more stable
pattern with less moisture expected to return on Monday and
prevail through most of next week.

&&

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

A surface high pressure anchored over the central Atlantic will
continue to promote moderate southeast winds through the short term
period. A mid to upper level trough currently over Cuba is forecast
to move across the forecast area between late tonight through
Saturday. This will promote instability and pooling of moisture
across the region. An upper level ridge is forecast to build behind
the trough on Sunday, but lingering low level moisture will aid in
the development of afternoon showers over western PR.

For today, a mid level ridge northeast of the region will continue
to promote a weak cap at 700 mb and trade wind showers in a
southeast wind flow will move at times across portions of the USVI
and east/southeast PR through the morning hours, minor rainfall
accumulations are expected. During the afternoon hours, models
suggest some divergence aloft as the trough moves over or just north
of Hispaniola. This will aid in the development of showers mainly
over the northwest quadrant of PR. On Saturday, the trough is
forecast to be in a better position to enhance shower activity
across the islands and the potential for thunderstorms will increase
mainly across the Atlantic waters. Urban and small stream flooding
is possible on Saturday with the heaviest showers.



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

The latest long term model guidance suggests that the weather
pattern will be more stable that what is expected this weekend.
The mid and upper levels will have a ridge of high pressure
by Monday and should prevail through the following workweek is the
models are correct. In addition, the available moisture will be
below normal with a few patches of moisture passing through. This
would cause a pattern of brief tradewind showers across the local
area, especially during the night and the morning hours that would
affect the USVI and eastern PR. The local winds will be generally
from the east and moderate, so there may be a chance of locally
induced afternoon showers across western PR. However, the mid and
upper levels would be so dry that it would be difficult to have
significant showers develop. Bottom line is that based on the
latest long term guidance, we would expect a fairly benign weather
pattern next week, with the exception of the marine conditions
which could deteriorate starting early or the middle of next
week.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals through the forecast period. However, SHRA btw 16z-22z
over northwest PR could cause tempo MVFR conditions. Southerly winds
will prevail at 10-15 knots. TS possible across the offshore
Atlantic waters tonight through Saturday.

&&

.MARINE...The small craft advisory for the offshore Atlantic
waters continues in effect until this evening due to seas up to 7
feet. Elsewhere, we can expect choppy seas up to 5 or 6 feet
today. Seas expected to be somewhat tranquil on Sunday into
Monday, but a northerly swell may move in by Tuesday or Wednesday,
causing the marine conditions to deteriorate and become hazardous
for the next several days thereafter.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 87 75 / 50 30 40 60
STT 82 75 82 74 / 20 40 40 60

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
517 AM AST Sat Feb 16 2019

.SYNOPSIS...Surface high pressure across the east central Atlantic
will continue to promote a moderate southeasterly wind flow today
but winds will shift to an easterly direction on Sunday and
Monday, then east northeast on Tuesday. Mid and upper level trough
will pass through the local area today but ridging will dominate
next week. The available moisture will linger today but will
diminish significantly by Monday.


&&

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

Satellite imagery and model guidance suggested the axis of an upper
level trough over the local region. Moisture will gradually increase
under a southeasterly wind flow, but upper level dynamic does not
look favorable for widespread convection across the region. However,
pesky showers should not be ruled out across the U.S. Virgin Islands
and the north, east and south sections of Puerto Rico during the
morning hours followed by afternoon convection across the interior
and western sections. A mid to upper level ridge is forecast to
build aloft promoting a seasonal weather pattern by early next week.

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

The long term forecast looks fairly benign with a rather stable
weather pattern. Mid to upper level ridge will dominate and the
available moisture will be below normal, but some patches of
moisture will move through causing brief showers across the USVI
and eastern PR. The forecast soundings show strong cap and very
dry mid levels, which will make it very difficult for locally
induced showers to develop in the afternoon across western PR.
Therefore, given the latest guidance we expect mostly fair weather
in the long term forecast with brief showers at times.


&&

.AVIATION...Mainly VFR conditions are expected to prevail through the
forecast period. However, SHRA may develop over Puerto Rico terminal
sites at times. Thunderstorms may develop over the Atlantic Offshore
waters outside of the CWA. SHRA/-SHRA will develop across NW-PR btwn
16/16-22z. Winds will return from the southeast at 10 to 15 kts with
higher gusts and sea breeze variations after 16/13Z.

&&

.MARINE...Small craft should exercise caution due to seas up to 6
feet across the Atlantic waters, seas 3 to 5 feet elsewhere.
Moderate southeast winds to persist today, becoming easterly on
Sunday. marine conditions expected to deteriorate by Wednesday of
next week with a northerly swell and fresh east northeast winds.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 74 86 74 / 30 50 40 20
STT 83 75 83 73 / 20 50 50 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
437 AM AST Sun Feb 17 2019

.SYNOPSIS...Near normal moisture will liner today across the local
area before drier air moves in on Monday. The drier airmass will
prevail through the upcoming workweek with a few brief patches of
moisture passing by. Surface high pressure across the east
central Atlantic and a weakening surface trough across the western
Atlantic will continue to cause moderate east southeasterly winds
today, but winds will become more easterly on Monday then east
northeasterly by midweek as a surface high enters the western
Atlantic. Upper low in the area today will move east then an upper
ridge will move in during the upcoming workweek. Showers are
expected this afternoon across central and western Puerto Rico,
but fair weather is expected to prevail for much of the upcoming
workweek.

&&

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

An upper level ridge will build over the the southwestern Atlantic
into the local area and hold for the next several days. This will
keep stable conditions across the region. At the surface, a weak
surface high pressure northeast of the region will promote moderate
east-southeast winds today. Another surface high is forecast to
build over the western Atlantic and winds will increase and turn
more from the east-northeast by Tuesday. On this pattern, fair
weather conditions should prevail each day with shallow afternoon
convection due to local effects over the western sections of the
islands and passing trade wind showers across the regional waters.
Moisture seems to reach a minimum on Monday and mostly rain free
conditions are expected across the islands. A slight increase on low
level moisture returns on Tuesday, but only minor rainfall amounts
are expected.

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

Fair weather is expected to prevail in the long term forecast. Dry
airmass is expected to persist and only a few brief patches of
moisture are expected to move through, which may bring some brief
shower to the local area. The mid and upper levels will maintain a
stable atmosphere as well. Latest forecast soundings still
indicate a strong inversion and very dry mid levels, which is
consistent with the mid and upper level ridges and low
precipitable water values. East to east northeast winds of 15 to
20 mph are expected across the local waters and coastal areas. So
given the stable atmosphere, dry air, and breezy conditions,
mainly fair weather conditions are to be expected with moments of
brief showers during the night and morning hours. That said, the
marine conditions are expected to deteriorate starting midweek,
more on that in the marine section below.


&&

.AVIATION...Mainly VFR conditions expected across all terminals
during the next 24 hours. However, shra over western PR could cause
tempo MVFR conds at TJMZ btw 16z-22z. Surface winds will prevail
from the east at 10-15 kt with sea breeze variations after 14z.


&&

.MARINE...Tranquil marine conditions expected today and Monday as
seas are expected to be generally between 3 and 5 feet and winds
at 10 to 15 knots. However, conditions will gradually become
hazardous by midweek. Winds will increase up to 20 knots starting
late Monday night and persisting at 15 to 20 knots with higher
gusts for several days thereafter. Northerly swell may invade the
local waters by Tuesday, causing seas to become choppy and up to 6
feet. However, hazardous seas up to 7 feet could be observed
starting on Wednesday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 74 85 74 / 10 20 10 30
STT 83 73 85 73 / 20 10 10 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
516 AM AST Mon Feb 18 2019

.SYNOPSIS...
The combination of a dry air mass and a mid-to-upper level high
pressure will maintain stable weather conditions across the
islands through much of this week. However, the seasonal advective
pattern associated with patches of low level moisture will bring
occasional showers from time to time. The mid-level high pressure
will make difficult afternoon convection across the western
sections especially today.

&&

SHORT TERM...Today through Wednesday...

Mainly stable weather conditions will prevail across the forecast
area throughout the period as a mid to upper-level ridge will build
overhead. In addition, this ridging pattern will also result in the
strengthening of a fairly robust low-level inversion, which will
serve to maintain moisture profiles below normal. Therefore, most of
the area is expected to observe mainly fair weather conditions. Any
showers that do affect the local area will be as a result of the
small patches of low-level moisture embedded within the trade wind
flow, however, the activity is expected to be isolated and brief
with very light accumulations. A surface high pressure across the
east-central Atlantic and another surface high pressure set to move
across the western Atlantic between late Tuesday and Wednesday will
result in a tightening of the local pressure gradient. This will
result in breezy conditions with winds expected to range between 10
and 20 mph with higher gusts.

.LONG TERM...Thursday through Tuesday...
Fair weather conditions will prevailed through the long term
forecast. A mid-upper level ridge will promote subsidence limiting
convection across the islands. Forecast soundings continues to
suggest the presence of a strong trade wind inversion which is
consistence with drier than normal conditions at mid-to-upper
levels as depicted in the vertical cross-section. However, breezy
trade winds will bring patches of low level moisture with
embedded clouds and showers across the windward sections of Puerto
Rico and the U.S. Virgin Islands each days. A similar weather
pattern will persist throughout the long term forecast.

A migratory high pressure across the Atlantic waters will
strengthen the local pressure gradient increasing the easterly
winds between 15 and 25 knots especially across the local waters
and coastal sections by mid-week into the upcoming weekend.

&&

.AVIATION...
VFR conditions are expected to prevail across all terminals
throughout the forecast period. Winds less than 10 kts through
18/14z, becoming east between 12 and 18 kts with higher gusts and
sea breeze variations afterwards.

&&

.MARINE...
Mariners should exercise caution across most of the local waters
as easterly winds are forecast to increase between 15 and 20
knots. Therefore, choppy seas will range between 4 and 6 feet
across most of the expose local water, while the protected areas
could expect seas at 4 feet or less.

A surface high pressure building across the Central Atlantic will
increase winds and seas across the Caribbean Offshore Waters and
Mona Passage late tonight. Conditions will become hazardous with
increasing seas up to 7 feet and winds between 15 and 25 knots
For that reason, a small craft advisory is in effect from late
tonight through at least Friday. Model guidance continue to
suggest hazardous winds and seas spreading across most of the
local waters after Tuesday night and continuing through the
upcoming weekend.

&&

.FIRE WEATHER...
Fire danger statements will be issued along the southern plains of
Puerto Rico as RH values are expected to drop significantly
between Cabo Rojo and Camp Santiago Raws Stations. The limiting
factor will be the winds which are not expected to reach Red Flag
Warning criteria.

A drying trend is expected to persist through much of this week.
Winds are expected to increase after late tonight and continuing
through the weekend. KBDI values shows that soils are significantly
dry with values above 700 at Cabo Rojo and Camp Santiago. Given
that the forecast calls for the continuation of a relatively dry
weather pattern and increasing winds, the chance for fire weather
conditions will remain high through the upcoming work-week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 72 84 74 / 0 20 20 20
STT 84 72 84 73 / 0 20 20 20