Caribbean - Central America Weather

[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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
454 AM AST Tue Feb 19 2019

.SYNOPSIS...
Fair weather conditions will prevail through much of the week.
However, a seasonal advective pattern will transport patches of
clouds and showers over the islands at times. A ridge pattern
aloft will limit afternoon convection across the interior and
western sections. Migratory surface high pressure will bring
breezy trade winds Wednesday through Friday.

&&

SHORT TERM...Today through Thursday...

Ridge aloft will continue to maintain a fairly stable weather
pattern across the forecast area through the period. At the surface,
a broad high pressure across the central and eastern Atlantic will
continue to produce breezy conditions with winds expected to range
between 10 and 20 mph with higher gusts. A stronger surface high
pressure is set to move over the western Atlantic Wednesday and
Thursday. This surface high pressure will further enhance the local
pressure gradient and therefore the winds. Winds both days are
expected to range between 15 and 25 mph with higher gusts.

Even though the ridge aloft is expected to produce mainly fair
weather conditions most of the time period, the strong low-level
trade wind flow will transport patches of low-level moisture across
the area from time to time. This will result in brief trade wind
showers, mainly across portions of eastern PR and the USVI. Across
western PR, shower activity is expected to be limited as the strong
low-level flow will prevent the formation of sea breezes, which
would normally enhance activity.

.LONG TERM...Friday through Wednesday...
The aformentioned surface high pressure will promote breezy trade
winds especially across the local waters and coastal sections through
at least Friday. Surface winds will slowly diminish through the
weekend.

Although a mid-to-upper level ridge will promote a fair weather
pattern through the forecast period, patches of moisture embedded
in the trades will result in passing showers across the windward
sections from time to time. 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 GFS continues to suggest.

&&

.AVIATION...
Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. Low-level cloud fragments could
result in -SHRA/VCSH across TJSJ/TIST/TNCM after 19/14z. A few brief
SHRA across western PR could result in VCSH across TJMZ after
19/18z. Surface winds below 10 knots through 19/14z, increasing to
15-20 kts with higher gusts from the E-ENE with some sea breeze
variations afterwards.

&&

.MARINE...
Mariners should exercise caution across most of the local waters
due to easterly winds between 15 and 20 knots and choppy seas up
to 6 feet. Small craft advisories continues in effect for the
Caribbean Offshore waters and Mona Passage due to seas between 5
and 7 feet with occasional seas up to 9 feet.

Migratory surface high pressure will deteriorate marine conditions
across most of the local waters as seas and winds are forecast to
increase between 6 and 8 feet and 15 to 25 knots, respectively.
These conditions are forecast to spread across most of the local
waters by Wednesday afternoon and continuing through the upcoming
weekend. Inexperienced mariners, especially those operating
smaller vessels should avoid navigating in these conditions.

&&

.FIRE WEATHER...
Once again, a fire danger statements (RFDSJU) 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 a surge of moisture which is
expected to reach the local islands by this afternoon. However,
critical values could be reach before the arrival of this airmass.

A drying trend will continue to persist through much of the week.
Winds are expected to increase between Wednesday and Friday. KBDI
values shows that soils are significantly dry with values above
700 at Guanica 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 much of the work-week.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Wed Feb 20 2019

..SYNOPSIS...
Cloudy conditions with passing showers will affect portions of the
islands throughout the day. However, a mid to upper level ridge
will promote stable weather conditions across the region. A
surface high pressure moving north of the region across the
Atlantic Waters will result in breezy trade winds through at least
Friday.

&&

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

Mid to upper-level ridge will continue to yield stable weather
conditions aloft and a robust inversion between the 700 and 775 mb
layer. This will prevent the development of deep convection and
therefore heavy rainfall activity through the period. However, just
enough low-level moisture will be present to result some light to
moderate trade wind showers across the area through the end of the
week. For today, a patch of low-level moisture will move across the
area. This will result in periods of brief showers affecting the
USVI and eastern portions of PR during the morning hours followed by
additional activity during the afternoon hours, mainly over eastern
PR. Less shower activity is expected on Thursday as drier air in the
low-levels moves overhead. Another round of trade wind showers is
expected on Friday as a band of higher low-level moisture, in
association with the remnants of a frontal boundary, moves over
the area. Once again, most of the shower activity is expected to
be concentrated across the eastern half of PR and the USVI.
Rainfall accumulations for the most part should remain light with
some minor ponding of water on roadways possible.

Windy conditions are also expected through the period. Strong
surface high pressure moving off the east coast of the United States
and across the western Atlantic will result in a tightening of the
local pressure gradient. This will result in winds ranging between
15 and 25 mph with higher gusts, especially near showers. Highest
winds are expected from the mid morning through early evening hours
each day.

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

Forecast soundings continues to suggest dry air at mid levels,
but enough low level moisture to result in trade wind showers from
time to time. Although a stable weather pattern will persist
during the long term, model guidance suggested an increase of low
level moisture and wind surface convergence late in the forecast
period. If this pattern holds, frequent patches of clouds and
quick passing showers could be expected Tuesday through Thursday.
However, confidence is low due to the amount of uncertainty
associated with the end of the forecast cycle.

&&

.AVIATION...
Mainly VFR conditions are expected across the terminals throughout
the period. VCSH/-SHRA are possible across TIST/TISX/TJSJ
terminals through 20/21z, which may result in brief MVFR
conditions. A few -SHRA are also possible across TJMZ between 20
/16z-22z. Winds will continue from the E-ENE around 10 kts
through 20/13z, increasing to 15-20 kts with higher gusts,
especially near SHRA, afterwards through 20/22z.

&&

.MARINE...
Fresh to locally strong trade winds will create rough seas across
most of the local waters. Seas will range between 5 and 7 feet
across the local waters increasing at 6 to 8 feet by Thursday.
Small craft advisories are in effect for the Caribbean and
Atlantic Offshore waters as well as across the local passages.
Hazardous conditions will diminish over the weekend but some areas
will persist with seas of 7 feet through early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 86 75 / 40 20 20 40
STT 84 73 85 74 / 40 20 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
515 AM AST Thu Feb 21 2019

.SYNOPSIS...Mid to upper-level ridge will continue to result in
stable weather conditions across the forecast area through early
next week. However, patches of low-level moisture embedded within
the trade wind flow will result in brief periods of trade wind
showers across the area. Surface high pressure north of the area
will continue to result in breezy conditions through the upcoming
weekend.

&&

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

A mid to upper-level ridge will continue to generate fair weather
conditions across the local forecast area today. A Strong surface
high pressure just east of the United States and across the
western Atlantic will result in a tightening of the local pressure
gradient and therefore increase the winds significantly across
the local area. Winds are expected to range between 15 and 25 mph
with higher gusts.

At this moment, satellite imagery shows an area of drier air moving
across the local region. Although this will decrease the shower
activity today, enough low level moisture will be available to
generate isolated to locally scattered passing showers through at
least mid morning. These showers will mainly affect northeast
portions of Puerto Rico and the northern Virgin Islands.

Satellite imagery is also showing an area of low level moisture
to the north of the local region, associated with the remnants of
a frontal boundary, and is forecast to reach our local region
between late tonight and Friday. Once again, most of the shower
activity is expected to be concentrated across the eastern half of
PR and the USVI. On Saturday expect isolated passing morning
showers mainly affecting the eastern half of Puerto Rico. A drying
trend is then expected by mid-morning.

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

Ridging aloft will continue to maintain a fair weather pattern
across the forecast area through Monday. However, occasional
patches of low-level moisture embedded within the easterly trade
wind flow will move over the area to result in brief periods of
trade wind showers. Rainfall accumulations, however, should remain
minimal.

Current model guidance shows the mid to upper-level ridge to erode
somewhat by midweek next week as a broad polar trough moves over
the Atlantic. This would weaken the trade wind cap and allow an
increase in the moisture content over the area. If this scenario
verifies, the potential is there for better showers to affect the
forecast area by the middle to latter half of next week.

&&

.AVIATION...Mainly VFR conditions are expected across the terminals
throughout the period. VCSH/-SHRA are possible across TIST/TISX/TJSJ
terminals between 21/09z-14z, which may result in brief MVFR
conditions. A few -SHRA are also possible across TJMZ between 21/16z-
22z. Winds will continue from the E-ENE around 10 kts through
21/12z, increasing to 15-20 kts with higher gusts afterwards.

&&

.MARINE...Choppy and hazardous wind driven seas between 5 and 7
feet are expected across most of the regional waters through the
upcoming weekend. Therefore, small craft advisories are in effect.
Surface winds will be out the east between 15 and 20 kts with
higher gusts.

There is a high risk of rip currents for Cramer Park Beach in
Saint Croix and a moderate risk for the rest of the local beaches
of the USVI and PR. A high risk of rip currents will go into
effect for the northern beaches of PR starting this evening.

&&

.FIRE WEATHER...Recent observations indicate that the soils across
the southern coastal plains of Puerto Rico remain very dry with
KBI values across portions of the southern coastal plains above
700. For today, a drier airmass will be moving overhead and with
winds expected to range between 15 and 25 mph with higher gusts,
relative humidity values are expected to drop between the 35 and
45% range. The combination of all these factors will result in a
high fire danger threat and therefore, a Red Flag Warning
(RFWSJU) was issued for the southern coastal plains of Puerto
Rico.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
423 AM AST Fri Feb 22 2019

.SYNOPSIS...Mid to upper-level ridge is expected to hold across
the area through at least Monday. This will continue to result in
a mostly stable weather pattern, however, small patches of low-
level moisture may result in some trade wind showers affecting the
area from time to time. Surface high pressure north of the area
will continue to produce breezy conditions through the upcoming
weekend. The ridge aloft is expected to weaken somewhat by the
middle of next week and may allow for better moisture to move
across the area and result in better shower activity.

&&

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

A surface high pressure north of the region will prevail through
at least Monday. This will continue to generate windy conditions
with winds expected to range between 15 and 25 mph with higher
gusts. Highest winds expected from the mid morning through the
evening hours.

Pulses of low level moisture will continue to move across the local
area from time to time. This will generate passing showers, mostly
affecting the local waters and the eastern areas of Puerto Rico.
These showers will be wind driven and therefore, be of short
duration with minor accumulations expected.

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

The ridge aloft will continue to maintain fair weather conditions
on Monday. By Tuesday and Wednesday, model guidance continues to
indicate that the ridge aloft will begin to weaken somewhat as a
deep polar trough moves across the western Atlantic. This would
cause a weakening of the trade wind cap and allow for better
moisture pooling across the region through the end of the work
week. If current model guidance continues to hold on its current
solution, the potential exists for better shower activity to
affect the local area starting on Tuesday and continuing through
the end of the work week.

&&

.AVIATION...Mainly VFR conditions are expected across the terminals
throughout the period. VCSH/-SHRA are possible across TIST/TISX/TJSJ
terminals through 22/09z-14z, which may result in brief MVFR
conditions. A few -SHRA are also possible across TJMZ between 22/16z-
22z. Winds will continue from the E-ENE around 10 kts through
22/12z, increasing to 15-20 kts with higher gusts afterwards
through 22/22z.

&&

.MARINE...Choppy and hazardous wind driven seas between 5 and 8
feet are expected across the regional waters through the upcoming
weekend. As a result, small craft advisories are in effect for
the majority of the regional waters. A high risk of rip currents
is in effect for the northern beaches of PR, Culebra, and Cramer
Park Beach in Saint Croix for today. The rest of the local beaches
have a moderate risk of rip currents. A high risk of rip currents
is expected for the northern beaches of Saint Thomas starting
this evening.


&&

.FIRE WEATHER...Recent surface observations indicate that the
vegetation across the southern coastal plains of Puerto Rico
continue to remain very dry with KDBI values near 600 in Cabo
Rojo and over 700 in Camp Santiago. Winds today will continue to
be moderate to strong with speeds ranging between 15 and 25 mph
with higher gusts. A band of low-level moisture, associated with
the remnants of a frontal boundary, will move across the area
during the day and will provide more cloudiness. Therefore,
relative humidity values are expected to be higher than they were
on Thursday but could still drop into the mid to upper 40s for a
few hours later this morning into this afternoon, maintaining the
fire weather risk elevated. Given this scenario, a fire danger
statement (RFDSJU) has been issued.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
433 AM AST Sat Feb 23 2019

.SYNOPSIS...A surface high pressure will maintain a fresh to
locally strong easterly wind flow through most of the forecast
period. Although fragments of moisture will move across the
region from time-to-time, a mostly stable weather pattern is
expected as a ridge aloft will continue to suppress the
development of deep convection. However, an increase in moisture
transport and a better chance for showers is expected by midweek
as the ridge aloft weaken somewhat. Due to wind driven seas,
hazardous marine and coastal conditions are expected through most
of the forecast period.


&&

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

A surface high pressure just east of the Bahamas and across the
western Atlantic will prevail through at least Monday. This will
maintain breezy conditions for the next several days. Available
moisture will remain limited through the weekend, causing mainly
fair weather conditions. Only shallow moisture patches are
expected to move across the local generating mostly isolated
showers across the local waters through at least Monday.

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

The latest model guidance suggests that as a surface high
pressure moves off the east coast of the United States and north
of the region, a fresh to locally strong wind flow will hold
across the forecast area through the end of the workweek. At the
same time, the ridge aloft is expected to erode somewhat as it
slowly drifts and spreads eastward over the central Atlantic while
a deep polar trough moves into the Atlantic. This combination
will weaken the trade wind cap and allow for an increase in
moisture transport across the forecast area while generating
favorable upper level conditions. If current model guidance
continues to hold on its current solution, a better chance for
shower activity can be expected by midweek and continuing through
the long-term forecast period.


&&

.AVIATION...Mainly VFR conditions are expected across the terminals
throughout the period. VCSH/-SHRA are possible across TIST/TISX/TJSJ
terminals through 23/09z-14z, which may result in brief MVFR
conditions. A few -SHRA are also possible across TJMZ between 23/16z-
22z. Winds will continue from the E-ENE around 10 kts through
22/12z, increasing to 15-20 kts with higher gusts.


&&

.MARINE...A surface high pressure located north of the region will
continue to promote a fresh to strong easterly wind flow across
the local islands today. This will result in hazardous marine
conditions with seas up to 8 feet and winds ranging between 15 and
20 knots with higher gusts. Thus, Small Craft Advisories (SCA)
continue in effect for all marine zones but coastal waters south
and southwest of Puerto Rico, where small craft operators are
urged to exercise caution. Marine conditions will begin to
progressively improve this evening and continuing through Monday
as the local pressure gradient weakens. However, this will be
short-lived as another strong surface high pressure is expected
to generate hazardous marine conditions by Tuesday.

For the coastal areas, a high rip current risk continues in
effect for beaches along the northwest to northeast coast of
Puerto Rico, as well as along the north coast of Culebra, Saint
Thomas and Saint Croix. Although coastal condition are expected to
progressively improve Sunday morning into Monday, a high risk of
rip currents will be required by late Monday night into Tuesday as
seas and winds increase once again.



&&

.FIRE WEATHER...Recent KBDI observations indicate that soils continue at
significant dry levels with values near or above critical
thresholds between 580-720 across the southern coastal plains of
Puerto Rico. Although today`s forecast calls for fragments of low-
level clouds to move further inland under a fresh to locally
strong easterly wind flow peaking at 15-20 mph, relative humidity
is expected to drop into the low 40s late this morning into early
this afternoon. These conditions could aggravate the drying
pattern that is affecting these areas, enhancing fire weather
conditions. As a result, a Fire Danger Statement has been issued.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 84 74 / 30 20 20 30
STT 80 77 80 77 / 20 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
406 AM AST Sun Feb 24 2019

.SYNOPSIS...A surface high pressure will maintain a fresh to
locally strong easterly wind flow until it weakens later today,
but breezy conditions will return late Monday as another surface
high pressure moves across the western Atlantic and north of the
region. A ridge aloft will maintain mostly fair weather conditions
until it weakens somewhat by Tuesday, allowing for an increase in
moisture transport with a better chance for showers by the latter
part of the week. A dry weather pattern will return as another
ridge aloft moves in and builds over the region by the upcoming
weekend.


&&

.SHORT TERM...Monday through Tuesday...

A similar fair weather conditions are expected to continue
through at least Monday morning with isolated to locally scattered
showers moving quickly across the local waters. Some of these
showers will move on shore and affect the eastern portions of
Puerto Rico and adjacent islands. These showers are expected to
move fast due to breezy conditions therefore rainfall
accumulations will be in the range of between trace and a few
hundredths of an inch.

Moisture is expected to slightly increase on monday as moisture
associated to an old frontal boundary now located North-Northeast of
the local forecast area. The moisture max influx will occur on
Monday afternoon. Therefore expect a slight increase on cloud and
shower coverage on Monday afternoon and Monday evening. Moisture is
expected to slowly decrease on Tuesday.


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

The latest model guidance continue to suggest that as a surface
high pressure moves off the east coast of the United States and
north of the region, a fresh to locally strong east to northeast
wind flow will hold across the forecast area through the end of
the workweek. In the meantime, the ridge aloft is expected to
erode somewhat as it slowly drifts and spreads eastward over the
central Atlantic while a deep polar trough moves into the
Atlantic. This combination will weaken the trade wind cap and
allow for an increase in moisture transport across the forecast
area while generating favorable upper level conditions. If current
model guidance continues to hold on its current solution, a
better chance for shower activity can be expected by Tuesday and
continuing during the latter part of the week. This will be
short-lived and a dry weather pattern will return as another mid-
level ridge moves in and builds over the region by the upcoming
weekend.


&&

.AVIATION...Mainly VFR conditions are expected across the
terminals throughout the period. VCSH/-SHRA are possible across
TIST/TISX/TJSJ terminals through 24/09z-14z, which may result in
brief MVFR conditions. A few -SHRA are also possible across TJMZ
between 24/16z-22z. Winds will continue from the E-ENE around 10
kts through 24/12z, increasing to 15-20 kts with higher gusts
during the day.


&&

.MARINE...Hazardous marine conditions are expected to continue
today across portions of the regional waters with seas between 5
to 7 feet and east winds between 15 and 20 knots with higher
gusts. As a result, Small Craft Advisories continue in effect. Although
conditions are expected to improve this afternoon into Monday,
the latest model guidance suggest that marine conditions will
deteriorate once again by Monday afternoon and continuing through
at least the end of the workweek.

Along the coastline, a high rip current risk continues in effect
for beaches along the north coast of Puerto Rico, Culebra, Saint
Thomas and Saint Croix. Along with improving marine conditions, a
the risk of rip currents will drop to moderate through at least
Monday afternoon.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 84 74 / 20 40 40 40
STT 80 76 80 76 / 20 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Mon Feb 25 2019

.SYNOPSIS...As a surface high pressure moves away into the north
central Atlantic winds will weaken somewhat today, but breezy
conditions will return as another surface high pressure builds
north of the region late tonight and continuing through the end of
the workweek. A ridge aloft will maintain mostly fair weather
conditions until it weakens somewhat by Tuesday, allowing for a
better chance for showers by the latter part of the week. However,
a dry weather pattern will return as another ridge aloft moves in
and builds over the region during the upcoming weekend.

&&

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

Quick surges of shallow trade wind moisture with embedded showers
continued to race across the region in the prevailing east to
northeast low level wind flow. Recent satellite imagery as well
as model guidance continued to suggest a gradual diminishing in
the prevailing winds and frequency of the moisture transport
during the early part of the period, as the surface high pressure
north of the region shifts further east into the central Atlantic,
and the local pressure gradient slightly relaxes. In the
meantime, mostly light passing showers will reach the north and
east coastal sections of some of the islands with rainfall is
expected to be brief and insignificant during the rest of the
morning hours. During the rest of the day a few showers may
develop over parts of the central and southwest sections of Puerto
Rico. This activity should be short-lived with no significant
rainfall anticipated during the rest of the day. Over the rest of
the islands, only a few showers expected but should be focused
mainly downwind of the islands or just offshore, as mostly sunny,
fair weather skies is expected during the afternoon hours. A
similar weather pattern is expected through Tuesday.

The mid to upper level ridge will hold across the region through
Tuesday to maintain overall dry and stable conditions. However the
ridge aloft is forecast to erode by Wednesday as a short wave
trough will enter and move across the western Atlantic. In the low
levels a frontal trough will lift east northeast across the
northwest Atlantic through Tuesday, but will weaken by Wednesday
as it will be quickly be replaced by another area of high pressure
which will build and spread across the west and southwest
Atlantic. This in turn will reinforce the dominant subtropical
ridge across the central and northeast Atlantic. Consequently a
return of the moderate to strong easterly trade winds and breezy
conditions is forecast by Wednesday with again a better chance for
more frequent quick passing early morning shower activity
followed by limited afternoon shower activity. That said, no
significant wetting rains is forecast for the period as any
rainfall across the islands will be limited and of short duration.

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

The latest model guidance continues to suggest that as a surface
high pressure moves eastward across the western Atlantic, a fresh
to locally strong east to east southeast wind flow will hold
across the forecast area through the end of the workweek. Then,
winds are expected to become moderate to fresh and turn from the
southeast as this feature continues to move into the north central
Atlantic and away from the region. In the meantime, a ridge aloft
is expected to erode somewhat as it slowly drifts and spreads to
the east over the central Atlantic. This will result in the
weakening of the trade wind cap and a better chance for shower
activity as the frequency of low-level moisture fragments,
associated to the remnants of a frontal boundary, increases by
Tuesday. This will be short-lived and a dry weather pattern will
return as another mid-level ridge moves in and builds over the
region during the upcoming weekend into early the following week.


&&

.AVIATION...VFR conds durg entire prd. SCT ocnl BKN lyrs nr
FL025... FL050...Few tops FL080. Wdly SCT -SHRA/SHRA ovr regional
waters and en route btw PR and the Leeward Islands. Sfc wnds calm
to LGT/VRB bcmg fm E-ENE 15-20 kts with ocnl hir gust aft 25/14z.
L/lvl wnds fm ENE btw 15-30 kts blo FL250. No sig operational wx
impacts attm.


&&

.MARINE...Small Craft Advisories will be in effect starting this
evening as wind driven seas increase up to 7 feet, particularly
for the outer Atlantic and Caribbean waters, as well as the local
passages. By late tonight into Tuesday morning, small craft
advisory conditions will spread across the coastal waters in part
due to winds increasing up to 25 knots with higher gusts. In the
meantime, small craft are urged to exercise caution across most of
the regional waters due to seas up to 6 feet and east to
northeast winds up to 20 knots. Relatively tranquil conditions
will prevail across coastal waters southwest of Puerto Rico and
south of Vieques and the U.S. Virgin Islands.

Along the coastline, a high rip current risk is in effect for
beaches along the north central to northeast coast of Puerto
Rico. As marine conditions deteriorate, a moderate risk of rip
currents will elevate to high late tonight into Tuesday morning
for beaches along the northwest and west coast of Puerto Rico, as
well as beaches along the north coast of Culebra, Saint Thomas and
Saint Croix. Elsewhere, a low to moderate risk of rip currents
will prevail.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 84 74 / 40 40 40 40
STT 85 74 84 73 / 40 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
518 AM AST Tue Feb 26 2019

.SYNOPSIS...Surface high pressure northeast of the local area will be
reinforced by another surface high pressure entering and moving across
the western Atlantic today through Wednesday. This will support moderate
to fresh east to northeast winds resulting in the transport of quick
passing low to mid level clouds and occasional showers across the region
through midweek. The mid to upper level ridge is expected to hold at
least until Wednesday, but will gradually erode by the end of the work
week and into the upcoming weekend, as a short wave trough is forecast
to enter and move across the west Atlantic.

&&

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

Shallow low-level moisture caused fast moving showers to continue to
develop across northern, eastern and southern areas of Puerto Rico
over the last several hours. This moisture is being pushed by the
strong easterly trade winds across the Atlantic ocean. Resent GOES-
16 Visible satellite imagery shows moisture moving into the southern
Caribbean waters from the east. Additionally, there is another surge
of moisture that is currently to the northwest of Saint Thomas that
is forecast to move through the eastern and northern areas of Puerto
Rico later this morning.

This afternoon shallow moisture embedded in the easterly trades will
continue to move across northern and eastern Puerto Rico, and
produce light to moderate rain. However, can not rule out scattered
showers developing elsewhere across the island either. The ridge at
the surface and aloft will hold across the area today, but late
tonight and early Wednesday the ridges will begin to weaken. A
frontal boundary currently 700 miles northwest of Puerto Rico will
continue to move to the east and cause the ridges to weaken and move
to the east of Puerto Rico. The trade wind cap will also weaken as a
result of the ridges moving to the east. Therefore, low-level
moisture is expected to increase on Wednesday and Thursday. The
increase in moisture will also increase the rain chances for most of
the area Wednesday and Thursday.

During the short-term period the mid to upper-levels of the
atmosphere will continue to be devoid of moisture. This will limited
to vertical development of showers through the period. The 26/00z
guidance has trended wetter than previous runs with rainfall.
However, at this time I went with consistence and will wait to see
if this trends continues over the next several model runs.

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

Surface high pressure across the eastern Atlantic and a surface
low with associated frontal boundary across the western Atlantic
will induce a moderate east to southeast winds across the local
area by Friday and into the upcoming weekend. The mid to upper level
ridge will then erode in response to a polar trough sweeping across
the west and southwest Atlantic. As the ridge aloft weakens so
does the trade wind cap inversion. This in turn will support a
better chance for sea breeze convergence and moisture pooling across
the islands. This expected pattern should then favor development
of scattered showers across portions of the regional waters and
portions of the islands especially during the overnight and early
morning hours. This will be followed by possibly some locally enhanced
afternoon shower activity on Friday and Saturday which should be focused
mainly over the central and west sections of Puerto Rico. A subtropical
jet segment moving just north of the region should also favor shower
development during that time.

A gradual drying trend is once again expected by Sunday and through
the end of the period as the mid to upper level ridge will
gradually build across the region once again, favoring an erosion
of low level moisture and a more typical easterly trade wind
weather pattern with seasonal temperatures.

&&

.AVIATION...VFR conditions will continue to prevail across all
terminal sites through 27/00Z. Sct SHRA will continue to pass across
terminals TIST, TISX, TJSJ AND TJPS through 26/18Z. Some mid level
clouds around 080 to 012 FL will continue to pass across PR
terminals this morning. Sfc winds out of the E to ENE at 15 to 20
kts with higher gusts possible.

&&

.MARINE...Choppy and hazardous marine conditions will continue
through at least mid-week due to a combination of a small
northerly swell and moderate to fresh east to northeast trade
winds. For the latest update and info, please refer to the Marine
Weather Message (MWWSJU) and Coastal Waters Forecast (CWFSJU)
issued by WFO SAN JUAN PR.

&&

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

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
512 AM AST Wed Feb 27 2019

.SYNOPSIS...
The doppler weather radar and recent satellite imagery continued to
detect several clusters of quick passing low to mid level clouds
and scattered to numerous showers across much of the forecast area.
Some of these showers brushed portions of the islands from time to
time and will continue to do so through the morning hours. The mid
to upper level ridge is expected to continue to erode over the next
few days as a polar trough will move across the west Atlantic. Consequently
the local trade wind cap inversion will weaken and therefore favor better
low-level moisture convergence through the end of the week. Prevailing
winds are expected to become more east to southeast by Friday as the
Atlantic high shifts eastwards into the central Atlantic.

&&

.SHORT TERM...Today through Friday...
Overnight a patch of moisture from the east Atlantic moved across
the region which generated numerous showers across eastern,
northern, and interior areas of Puerto Rico well into the morning
hours. Although, numerous showers were observed, rainfall
accumulations were light as a result of the showers fast movement.
GOES-16 visible imagery shows patches of moisture extending from
the Leeward Islands all the way across the central Atlantic ocean.
These occasional patches of moisture are forecast to continue to
affect the the local passages, Puerto Rico and the U.S. Virgin
Islands today through the end of the work week. As a result
periods of light to moderate rainfall is expected to continue to
move over the area.

The mid and upper-level ridge which prevailed over the area has
started to erode and shift to the east of Puerto Rico, thus the
trade wind cap which has limited shower development over the last
several days will continue to weaken over the next several days.
The weakening of the trade wind cap will allow moisture to continuously
filter in underneath the ridge through Friday. Additionally, the
added moisture will keep the low-level of the atmosphere moist and
increase precipitable water values across the area. Today winds
will be out of the east at 15 to 20 mph, however winds are forecast
to vary from the east to southeast by Thursday afternoon through
Friday. This will bring a return of moisture out of the Caribbean
up and over Puerto Rico.

The low-level convergence combining with upper level divergence just
north of the region will help sustain the influx of moisture and instability
across the area today and tomorrow. Partly cloudy conditions are expected
to prevail over the next several days and keep temperatures in the
lower to middle 80s near lower elevations, and the lower to middle
70s in higher elevations. The mid and upper- level of the atmosphere
will remain moisture free, therefore deep convection is not expected
to develop at this time.

.LONG TERM...Saturday through Wednesday...
Persistent Surface high pressure across the eastern Atlantic
along with an area of low pressure and an induced frontal trough
across the western Atlantic will create moderate east to southeast
winds across the region through the upcoming weekend. The mid to
upper level ridge is still forecast to erode in response to a
polar trough expected to lift east northeast across the western
Atlantic. The eroding ridge aloft will also support a weaker trade
wind cap inversion and therefore allow a better chance for sea
breeze convergence and moisture pooling across the islands at
least through Saturday and early Sunday. This expected pattern
should favor additional development of isolated to scattered
showers over the regional waters and portions of the islands
especially during the overnight and early morning hours. Some
locally enhanced afternoon showers will remain possible especially
on Saturday and should be focused mainly over the central and
west sections of Puerto Rico. Recent model guidance still suggest
the proximity of a subtropical jet segment moving just north of
the region and this should also favor better shower development
during that time.

A gradual drying trend is once again expected by Sunday afternoon and
through the end of the period as the mid to upper level ridge will
gradually build across the region once again, favoring an erosion of
low level moisture, increasing trade wind cap inversion and the
more typical easterly trade wind weather pattern with overall
seasonal temperatures.

&&

.AVIATION...Mainly VFR conditions will continue to prevail across
all terminal sites through 27/18Z. SCT to numerous SHRA will move
over the Puerto Rico and U.S. VI terminals as well as around the
Northern Leewards terminals through 27/18Z. Sfc winds will
continue from the E to NE between 15 and 20 kts with higher gusts
through 27/23z, diminishing to 8-15 kts afterwards.

&&

.MARINE...The surface high pressure will continue to spread eastward
into the central Atlantic during the next few days, while maintaining
moderate to fresh easterly winds. A northerly swell will also spread
across the Atlantic waters and local passages today. Therefore choppy
to hazardous seas are forecast to continue through at least the end
of the work week.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
540 AM AST Thu Feb 28 2019

.SYNOPSIS...

Patches of low-level moisture will continue to move across the
the region periodically over the next several days and cause
light to moderate showers. Showers will develop across the eastern
and northern areas of Puerto Rico, and the U.S. Virgin Island
during the morning. Then across western and interior areas of
Puerto Rico during the afternoons. The surface ridge will remain
east of the Puerto Rico through Saturday this will weaken the
trade wind cap, and allow more moisture to filter into the area.
However, the mid to upper-levels of the atmosphere will continue
to have limited moisture therefore showers will continue to be
short-lived. Early next week another trough moves into the
Atlantic waters which will cause the mid to upper-level ridge to
weaken again therefore expect rain chances to increase.


&&

.SHORT TERM...Today through Saturday...
The moderate easterly winds continued to bring clusters of low to
mid level clouds and passing showers to the region during the
overnight and early morning hours. Some showers produced brief
gusty winds and periods of moderate to locally heavy rains in
isolated areas. These frequent patches of trade wind moisture are
forecast to continue to affect the region through Friday and into
the upcoming weekend. This will support daily afternoon shower
development across parts of the islands each day. As a result
light to moderate rainfall is expected to continue to affect
portions of the islands with most of the expected rainfall
forecast to occur over parts e of the east sections of the islands
during the morning and over the central and northwest sections of
Puerto rico during the afternoon hours. The U.S. Virgin islands
can expected occasional passing showers each day with a gradual
improvement and lesser activity expected for the weekend.

The mid and upper-level ridge which prevailed over the area has
continued to erode and shift slightly east of Puerto Rico, while
relaxing the trade wind cap inversion which has limited shower
development over the last several days. The ridge will continue to
weaken over the next several days. The weakening of the trade
wind cap will therefore allow moisture to filter in underneath the
ridge through Friday. This added moisture will maintain the low-
level of the atmosphere fairly moist and increase precipitable
water values across the area. Winds are still forecast to become
more east southeast through Saturday and this will continue to
transport tropical moisture fragments across the region from time
to time.

The low-level convergence combining with upper level divergence just
north of the region will help sustain moisture transport and instability
across the area through the end of the week. variably cloudy to partly
cloudy conditions will prevail each day and therefore keep temperatures
in the lower to middle 80s near lower elevations, and the lower to
middle 70s in higher elevations. The mid and upper- level of the atmosphere
will remain moisture free, therefore deep convection is not expected
to develop at this time.

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

The surface ridge of high pressure will prevail across the eastern
Atlantic, thus promoting east to southeast winds during the
weekend. The mid to upper level ridges are expected to be east of
of Puerto Rico, as a result of the polar trough that will
continue to progress to the east during the weekend. The trough
impinging on the ridges will weaken the trade wind cap across the
region. The weaken cap will cause moisture to funnel across
Puerto Rico and the U.S. Virgin Islands this Sunday through early
next week. Additionally, moderate easterly winds of 15 to 20 mph
is expected to converge across the area, which will help induce
showers during the early morning and afternoon. Furthermore, the
subtropical jet that is forecast to be north or near the area
during the weekend, and early next week will also aid in shower
development across the area.

Tuesday through Wednesday the mid to upper-level ridge will build
across the area, which will increase the trade wind cap.
Resulting in the erosion of low-level moisture. However Thursday
a cold front is forecast to move into the Western Atlantic and
cause the mid to upper-level ridge to erode again, thus leading to
an increase in moisture across the area.

&&

.AVIATION....Prevailing VFR conds durg prd. SCT-Bkn lyrs nr
FL025...FL050..FL080 en route btw islands and ovr local waters
with Isold-Sct SHRA. Mtn top obscr ovr E PR til 28/12z. Sfc wnds
LGT/VRB bcmg fm E-SE 15-20 kts and ocnl hir gusts aft 28/14z.

&&

.MARINE...

Hazardous marine conditions will continue across the local and
outer waters through Friday morning. These conditions are being
created by easterly winds of 15 to 20 kts, and a northerly swell
that has moved into the local waters. Seas are up to 7 feet across
the outer Atlantic waters, while elsewhere seas are up to 6 feet.
Therefore a Small Craft Advisory is in effect. Seas are forecast
to gradually decrease tonight into early Friday morning. A high
risk of rip currents for northern, eastern, and western beaches of
Puerto Rico today. Additionally, there is a high risk of rip
current for Culebrita beach, and the beaches of Saint Thomas and
Saint Johns.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 87 74 / 40 20 20 20
STT 83 74 84 73 / 30 20 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
359 AM AST Fri Mar 1 2019

.SYNOPSIS...

A surface high pressure will keep the region in an east to
southeast wind flow through early next week. Therefore moderate to
fresh winds can be expected. The mid and upper-level ridge will
reestablish themselves across Puerto Rico and the U.S. Virgin
Islands on Sunday, thus strengthening the trade wind cap. The
trade wind cap will limit low-level moisture, and development of
deep convection today through early next week. However, shallow
moisture is expected to move through the region from time to time
over the next several days. The middle of next week the low-level
jet is forecast to be near or over Puerto Rico with winds of 80 to
90 kts, this along with a frontal boundary in the western
Atlantic will increase rain chances through the end of next week.

&&

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

Present satellite imagery and doppler weather radar showed very
shallow low level clouds with a few light to moderate showers moving
across the regional waters in the prevailing east to southeast wind
flow. A few of these showers will brush mainly the east coastal
sections of the islands during the rest of the morning hours. No
significant rainfall is however forecast for the period as an
overall dry and stable air mass is expected to filter in across the
region today and through the weekend. This scenario will therefore
lead to mostly fair weather and sunny skies across the islands.

Recent model guidance initialized fairly well with the present and
expected weather pattern, and continued to suggest a gradual drying
trend with decreasing precipitable water over the weekend. Very
little moisture transport is forecast across the region although the
mid to upper level ridge will slightly erode through Sunday and
support local sea breeze convergence. Any afternoon shower activity
is expected to be of short duration in the form of streamers,
steered by the prevailing east southeast wind flow. Most of the
shower development today and through the weekend should be limited
to mainly parts of the central interior and west to northwest Puerto
Rico. Rainfall accumulations for the most part should remain fairly
light under the present and expected conditions. Mostly fair weather
skies should prevail in and around the U.S. Virgin Islands, and any
afternoon shower activity should be mainly downwind of the islands
and over the coastal waters. Daytime high temperature should be near
or slightly above normal in the some areas along the north coastal
areas under the prevailing southeast wind flow through most of the
weekend.

&&

.LONG TERM...

Fair weather with isolated to scattered showers are expected
during the beginning of the long-term period. The mid and upper-
level ridge will reestablish themselves across the region on
Sunday, and strengthen the trade wind cap. As the trade wind cap
strengthens it will limit the low-level moisture over Puerto
Rico, and the U.S. Virgin Islands through early Tuesday. Therefore
only light to moderate showers are expected across Puerto Rico
and the U.S. Virgin Islands during the overnight and early
mornings hours. Then showers will move to the western and interior
areas of Puerto Rico during the afternoon. Additionally, a
surface trough south of Puerto Rico will pull dry continental air
from South America across the Caribbean, which will inhibit deep
convection from developing, as well as, the drier air in the mid
and upper-levels of the atmosphere. Therefore only light rainfall
amounts are expected at this time.

Winds will be out of the east to southeast ranging from 15 to
20 mph through late Wednesday, then winds will back to the east
to northeast through. Thursday a cold front is forecast to move
into the Western Atlantic and cause the mid to upper-level ridge
to erode again. In addition, the subtropical jet is forecast to be
near or over Puerto Rico with winds ranging from 80 to 90 kts.
These features along with low-level moisture will lead to an
increase in showers across the region through the end of the
work week.

&&

.AVIATION...

VFR durg entire prd. SCT ocnl BKN lyrs nr FL030...
FL050...FL080 en route btw islands and ovr regional waters with
mstly isold -SHRA/SHRA. Sfc wnd calm to LGT/VRB bcmg fm E-SE 10 to
15 kts with sea breeze variations. Isold-SCT VCSH psbl nr TJMZ/TJBQ
and ovr CTRL and W PR 01/17Z-01/22Z. Otherwise no sig operational wx
impacts attm.

&&

.MARINE...

Choppy to hazardous seas will continue across the Atlantic
waters today through the weekend. The combination of a moderate to
fresh easterly winds and a northerly swell will result in a small
craft advisory today. Elsewhere, seas will range from 4 to 6 feet
therefore small craft operators are urged to exercise caution.
Marine conditions are forecast to continue to improve over the
next several days. A high risk of rip currents for northern and
eastern beaches of Puerto Rico. There is high risk of rip currents
for Culebrita beach, Saint Thomas and Saint Croix.

&&

.FIRE WEATHER...

Recent KDBI observations indicate that soils are still relative
dry with values near or above critical thresholds between 580 to
720. These conditions are occurring across the southern and
western coastal plains of Puerto Rico. In addition, current
guidance shows limited low-level moisture across the region
through the weekend. This will limit wetting rains that could help
condition across the plains. Furthermore, east to southeast winds
of 15 to 20 mph will continue to dry out fuels today through the
weekend. As a result of drier conditions and strong easterly winds
relative humidities values are forecast to be near the lower to
middle 40s during the afternoon for a couple of hours or so.
Therefore fire danger will be elevated and a fire danger statement
has been issued today.


.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 84 73 / 20 30 20 30
STT 81 74 80 75 / 20 40 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
341 AM AST Sat Mar 2 2019

.SYNOPSIS...A fairly stable weather pattern is expected to
prevail through early next week, as a result of the surface high
across the northeastern Atlantic. In addition, the surface high
will continue to promote east to southeast winds across Puerto
Rico and the U.S. Virgin Islands through early next week. An
increase in showers is expected next week as an upper-level trough
moves into the Atlantic and weakens the surface high. The
weakening of the surface high will weaken the trade wind cap, and
cause low- level moisture to filter in underneath the surface high
east of the Leeward Islands. Also, an upper-level jet is forecast
to be north or slightly over the region this weekend into the
middle of next week. The low-level moisture combining with the
added moisture will also help increase the chance of rain across
the region.

&&

.SHORT TERM...Today through Monday...
High pressure at the surface will shift westward to the sub
tropical central Atlantic during the period to maintain moderate
to fresh east to east southeast flow during the period. Mid levels
will see persistent high pressure. At upper levels, a ridge over
the eastern Caribbean will lean over into the western tropical
Atlantic and allow a jet streak of 65 knots to migrate southeast
over the area on Monday.

The high pressure at mid and upper levels and the very dry
atmosphere that accompanies them will prevent deep convection.
Nevertheless some passing showers will move onshore over the
islands overnight and early morning each day, and heating should
be sufficient to generate afternoon showers in west northwest
Puerto Rico as patches of moisture in the prevailing trade wind
flow cross from time to time.

&&

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

A relatively fair weather pattern is expected during the
beginning of the long-term period. Isolated to scattered showers
will develop across northern, and eastern portions of Puerto Rico
during the morning, then showers will move to the western and
interior during the afternoon. Furthermore, due to the lack of
deep moisture because of the trade wind cap, showers will be
brief with light rainfall accumulations through Wednesday.

A front will move into the Atlantic waters on Monday, and weaken
the surface high in the central Atlantic. The weakening of the
surface high will also weaken the trade wind cap across the
Caribbean. As a result, an increase in moisture is expected
during the middle of the week. In addition, the jet streak that is
forecast to develop this weekend will remain over Puerto Rico or
just slightly north. The jet will provide some instability to the
upper-levels of the atmosphere. This added instability should
enhance shower development Wednesday through Saturday. However,
the mid and upper-levels of the atmosphere will continue to be
devoid of moisture, thus limiting the vertical development of the
showers.

&&

.AVIATION...VFR durg entire prd. SCT ocnl BKN lyrs nr FL050...FL080
en route btw islands and ovr regional waters with mstly isold -
SHRA/SHRA. Sfc wnd calm to LGT/VRB bcmg fm E-ESE 10 to 15 kts with
sea breeze variations. Isold-SCT VCSH psbl nr TJMZ/TJBQ and ovr CTRL
and W PR 02/17Z-02/22Z. Otherwise no sig operational wx impacts.
Maximum winds W 45-55 kt btwn FL380-430 until 03/06Z.

&&

.MARINE...Choppy marine conditions are expected over the next
several days. As a result of east to southeast winds of 15 to 20
kts. Therefore, small craft operators are urged to exercise
caution through the weekend. Seas will range from 3 to 5 feet.
There will be a high risk of rip currents for the Culebrita beach
today. Elsewhere, there is a low to moderate risk of rip currents.


&&

.FIRE WEATHER....

Recent KDBI observations indicate that soils are still relative dry
with values near or above critical thresholds. These conditions are
occurring across the southern, western and portions of the central
coastal plains of Puerto Rico. In addition, current guidance shows
limited low-level moisture across the region through early next
week. This will limit wetting rains that could help condition across
the plains. Furthermore, east to southeast winds of 15 to 20 mph
will continue to dry out fuels today through the weekend. As a
result of drier conditions and strong easterly winds relative
humidities values are forecast to be near the middle 30 to lower 40s
during the afternoon for a couple of hours or so. Therefore fire
danger will be elevated and a red flag warning has been issued today.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 85 73 / 20 30 30 40
STT 81 75 81 75 / 20 30 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
451 AM AST Sun Mar 3 2019

.SYNOPSIS...A relatively stable weather pattern is expected
through the middle of next week. Patches of shallow moisture from
the east will move into the area over the next several days and
cause light showers across the eastern, and interior areas of
Puerto Rico during the mornings. Then across portions of interior
and western areas during the afternoons. A surface ridge in the
northeast Atlantic will continue to hold through the middle of the
week. A upper level trough is expected to deepen to the northeast
of Puerto Rico by Thursday. This trough will cause the surface
ridge to weaken and retreat northeast, and as it does low-level
moisture is expected to increase across the region late Friday and
into the weekend. This will increase showers late next week into
the weekend.

&&

.SHORT TERM...Today through Tuesday...
High pressure will drift westward into the central Atlantic as
vigorous low pressure centers over the Atlantic just east of New
England and also over South Carolina are deflected to the
northeast. Their associated cold fronts will not threaten or
affect Puerto Rico or the U.S. Virgin Islands. At mid levels high
pressure prevails. At upper levels the ridge to our east continues
moving east but early this week another ridge builds over Puerto
Rico and the USVI and a jet streak of 70 knot westerlies
strengthens directly over the area.

This leaves only passing patches of moisture to bring shallow
showers. Some of these patches are extensive enough about 24 hours
upstream to bring good chances of light amounts to the east coast of
Puerto Rico and to a lesser extent the U.S. Virgin Islands--mainly
during the early morning hours. Showers are also expected to form in
western Puerto Rico during the early afternoons with some showers
yielding more than one tenth inch in the favored areas.

&&

.LONG TERM...Wednesday through Saturday
A cold front is forecast to be to the northwest of Puerto Rico
late Wednesday into Thursday morning. Patches of moisture across
the eastern Atlantic will move across the area periodically on
Wednesday and Thursday. This shallow moisture will help induce
showers across the U.S. Virgin Islands, and portions of eastern
and northern Puerto Rico during the morning hours. Then showers
will move across interior and western areas of Puerto Rico during
the afternoon. However, current guidance has the whole atmospheric
layer relative dry.

Precipitable water values on Wednesday and Thursday have values
ranging from 1.0 to 1.30 inches. In addition, a strong trade wind
cap will be present during the middle to end of the work week.
These factors will inhibit development of deep convection, and
keep rainfall accumulations light.

Friday the front is expected to progress further southeast and
a weak trough aloft will move in from the west. Surface winds
will be out of the east to northeast at 15 to 20 mph. The lower
levels of the atmosphere are forecast to begin very dry on Friday
with precipitable water values below 1.0 inches, but moisture
increases into Saturday as a mid level TUTT cuts off to the east
of the Leeward Islands, and an increase in moisture is expected.
The TUTT low to the east of the area will weaken the trade wind
cap on Saturday, which will increase rain chances across the U.S.
Virgin Islands and Puerto Rico. Furthermore, the troughiness to
the north of the Islands will enhance the mid to upper-level
instability to further enhance shower development.

&&

.AVIATION...VFR durg entire pd except for brief periods of MVFR bfr
03/14Z in TISX/TNCM/TKPK. Sct-isold -SHRA/SHRA arnd PR/USVI but
focus will shift to interior and wrn PR aft 03/17Z with ocnl mtn
obscurations. Sfc winds E 12-18kt with gusts to 22 kt. Max winds WSW
50-65 knots btwn FL330-430 increasing to 55-70 kt aft 03/20Z.


&&

.MARINE...Choppy marine conditions are expected over the next
several days. As a result of east to southeast winds of 15 to 20
kts, and seas up to 6 feet. Therefore, small craft operators are
urged to exercise caution. A low to moderate risk of rip currents
for all the local beaches of Puerto Rico, U.S. Virgin Islands,
Saint Thomas and Saint Johns today.

&&

.FIRE WEATHER...Recent KDBI observations indicate that soils are
still relatively dry with values near or above critical
thresholds. These conditions are occurring across the southern,
western and portions of the central coastal plains of Puerto Rico.
In addition, current guidance shows limited low-level moisture
across the region through early next week. This will limit wetting
rains that would help the dry conditions across the plains.
Furthermore, east to southeast winds of up to 16 mph will continue
to dry out fuels today through the weekend. As a result of drier
conditions and strong easterly winds relative humidities values
are forecast to be near the middle 30 to lower 40s during the
afternoon for a couple of hours or so. Therefore fire weather
danger discussion has been issued today.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 83 73 / 20 50 40 40
STT 83 74 84 74 / 30 60 40 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST Mon Mar 4 2019

.SYNOPSIS...Patches of moisture and moderate to fresh trade winds
will continue across the area. Showers will increase in coverage
and intensity somewhat on Friday and Saturday as moisture deepens.
Otherwise high pressure at low and mid levels will continue to
restrain fronts associated with migrating lows out of the United
States from coming very close to Puerto Rico.

&&

.SHORT TERM...Today through Wednesday...
Ridge aloft will continue to maintain very dry conditions above
700 mb during the period. This will prevent the development of
deep convection. At low-levels, a surge in low-level moisture is
expected across the area for today. This will result in an
increase in trade wind shower activity. Scattered showers are
expected across portions of eastern PR, the USVI, and surrounding
waters during much of the morning hours. This be followed by the
development of showers across northwest PR during the afternoon
hours, where activity could be more enhanced due to sea breeze
convergence and daytime heating. At this time, only expecting
ponding of water on roadways and in low-lying areas to be the
main hazard with these showers.


For Tuesday, slightly lower low-level moisture will move overhead
and therefore, lesser showers are expected compared to today.
However, there can still be some brief morning showers moving across
portions of eastern PR and the USVI followed by the development of
afternoon showers across western PR due to daytime heating and local
effects. On Wednesday, the low-level flow is expected to decrease to
less than 10 knots as the local pressure gradient relaxes due to a
frontal system moving across the western Atlantic. Therefore,
afternoon shower activity is expected to favor interior PR and
could lead to higher accumulations.

.LONG TERM...Thursday through will Monday...
High pressure at the surface over the central Atlantic will drift
eastward. This will allow a front to sink into the Atlantic
waters North of Puerto Rico and the U.S. Virgin Islands north of
20 degrees north latitude. But moisture will remain limited on
Thursday. Moisture deepens and increases Friday and Saturday,
intruding into the mid levels somewhat then. This will allow
somewhat more frequent showers, but mid level dryness persists
with high pressure in the Caribbean during the period only
somewhat displaced toward central America as a weak trough at mid
and upper levels passes north of the area Saturday.

The trade wind flow varies little from its easterly direction and
will remain 15 to 25 knots through Monday carrying persistent
light to moderate showers across the region to bring late night
and morning showers in the USVI and eastern Puerto Rico and
heavier rains in western Puerto Rico during the afternoons.

&&

.AVIATION...Mainly VFR conds are expected to prevail across all
terminals during next 24 hrs. Trade wind SHRA are expected to
move across the Leeward Islands, USVI, and ern PR thru 04/16z,
resulting in VCSH/SHRA mainly across TJSJ/TIST/TISX/TNCM/TKPK.
This could create brief MVFR conds. SHRA are expected across wrn
PR btwn 04/16z-22z, affecting TJMZ and TJBQ. Winds blo 10 kts from
the E-ESE thru 04/13z, incrg to btwn 12-18 kts with sea breeze
variations afterwards. Maximum winds W 50-55 kt btwn FL330-420.

&&

.MARINE...Seas will continue choppy in the outer Atlantic and
Caribbean waters and portions of the Atlantic inner waters around
Puerto Rico through much of the week. Small craft advisories are
still expected Friday and Saturday for seas of 7 feet--mainly in
the outer waters. Rip current risk is expected to come up to high
for a few days then.

&&

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

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Tue Mar 5 2019

.SYNOPSIS...Moisture out of the central Atlantic will continue to
bring light to moderate but brief showers to Puerto Rico and the
U.S. Virgin Islands. Convergence and weaker flow in northwest
Puerto Rico will allow heavier showers to form during the
afternoons drawing from the shallow moist layer. Weak short-wave
troughs at upper levels will enhance these showers, Friday,
Saturday and Monday, but marked drying is expected beginning early
next week.

&&

.SHORT TERM...Today through Thursday...
Surface high pressure over the north central Atlantic will continue
to generate a moderate to fresh east to east southeast wind flow
across the region. Satellite imagery shows a cluster of clouds
moving over the Leeward islands, expected to reach the local
islands today. This will result in showers affecting portions of
the U.S. Virgin Islands and eastern Puerto Rico during the morning
hours. Although a ridge aloft continues to maintain very dry
conditions above 700 mb, the combination of a weak wind, an
inversion and a subtropical jet maximum combined with lingering
low-level moisture will enhance diurnal convection, particularly
across the interior and northwestern Puerto Rico in the afternoon.

Models suggest that an area of relatively dry air will begin to
infiltrate the region Wednesday and continuing through Thursday.
This is expected to occur as the winds gradually become east-
northeast with the approach of a frontal boundary that will stall
north of the local islands through the short-term period.
Overhead, little to no changes are expected. Despite the presence
of drier air and total precipitable water values ranging between
0.90 and 1.25 inches, afternoon convection remains possible each
day. That is, with the focus of the activity shifting from the
northwestern quadrant on Wednesday to the southwestern quadrant on
Thursday following the trade wind flow. Elsewhere, fair weather
conditions are expected, with mostly sunny to partly cloudy skies
and little or no shower activity.

.LONG TERM...Friday through Tuesday...
The frontal boundary settling into the western Atlantic waters
just north of Puerto Rico and the U.S. Virgin Islands and an
associated pre-frontal trough will hold moisture near the area and to
the northwest on Friday. This will also keep the local area under
relatively moist conditions (for the season) over the weekend,
generating scattered to numerous showers over Puerto Rico and
scattered or isolated showers for the U.S. Virgin Islands.
Northerly flow then brings slightly cooler and slightly drier air
over the area on Monday and Tuesday. The northerly flow, however
will also bring some scattered showers from the very shallow
moisture that will be forced over the higher terrain of Puerto
Rico on Tuesday morning that will reform on the southwest side of
Puerto Rico during the afternoon according to the GFS.

At mid levels weak troughiness north of the area will hold over
Puerto Rico for all but Monday and Tuesday with moisture barely
protruding into the mid levels over the weekend. A cut-off low
will form northeast of the area and bring northerly flow at mid
levels to enhance the northerly flow in the lower layers late
Sunday through Tuesday, that should produce slightly cooler and
drier days everywhere except for scattered showers along the north
coast of Puerto Rico.

At upper levels a weak trough with a mini jet streak of 85 to 90
knots will pass through on Friday afternoon, followed by an
emerging trough in the upper level flow on Saturday afternoon.
Another short wave in the overall northwesterly flow will be
enhanced by the cut-off low to our northeast on Sunday and pass
through on Monday evening. Each of these features will have a weak
but noticeable effect on the shower activity in western Puerto
Rico and the transient showers in the trade wind flow during the
period. No other significant features are noted.

&&

.AVIATION...mainly VFR conditions expected across all terminals
during the next 24 hours. Occasional VCSH expected across
TJSJ/TIST/TISX/TNCM/TKPK terminals through 05/14Z. Afternoon
convection will result in VCSH/SHRA across TJMZ and TJBQ around
05/16-23Z. This could result in brief MVFR conditions. Light and
variable winds expected through 05/14Z, increasing to 10-15 kt
from east-southeast afterwards with sea breeze variations.

&&

.MARINE...Winds of 16-18 knots across the Atlantic will bring seas
in the northeast portion of our forecast area to 7 feet today and
this evening. Currently small craft advisory conditions are not
expected for the next 8 days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 72 85 72 / 40 30 30 40
STT 84 73 84 73 / 10 10 10 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
459 AM AST Wed Mar 6 2019

.SYNOPSIS...Patches of moisture will drift across the area from
time to time bringing showers with light to moderate amounts of
rain. Easterly trade wind flow will become east northeast on
Friday and showers will shift to the southwest portion of Puerto
Rico in the afternoons and the northern slopes and coastal plains
during the overnight and morning hours. Drying is indicated after
Monday.

&&

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

Surface high pressure over the north central Atlantic will continue
to generate a moderate to fresh east to east southeast wind flow
across the region. Satellite imagery shows a cluster of clouds
embedded in the trades moving over the Leeward Islands and
approaching the U.S. Virgin Islands. This patch is expected to move
across the local islands today, resulting in increased cloud cover
and showers affecting portions of the U.S. Virgin Islands and
eastern Puerto Rico, particularly during the morning hours. Although
a ridge aloft will continue to maintain very dry conditions above
700 mb and a strong trade wind cap, low-level moisture combined with
daytime heating and local effects will enhance afternoon convection,
particularly across the interior and northwestern Puerto Rico in the
afternoon, as well as downwind from the local islands and El Yunque
area. As a result from this activity, total rainfall accumulations
between half an inch to an inch can be expected over portions of
eastern and northwestern Puerto Rico today.

The latest model guidance suggest that a similar weather pattern is
expected through the rest of the short-term forecast period with
variations in frequency, coverage and the location of peak
convective development each day as altering patches of dry/moist
air drift across the region. Shower activity will be focused along
the Cordillera Central, but favoring the southwestern quadrant as
winds become northeast during this period. TPW values are
expected to drop to near an inch on Thursday as a drier air mass
infiltrates from the east, increasing up to 1.40 inches on Friday
afternoon as another patch of low-level moisture quickly moves
over the islands. That said, and with a slight weakening of the
mid-level inversion and somewhat favorable upper level conditions
due to a subtropical jet maxima overhead, the most active period
is expected on Friday with rainfall accumulations near an inch
southwest and interior Puerto Rico with isolated higher amounts.

.LONG TERM...Saturday through Wednesday...
High pressure in the central Atlantic will move to the northeast,
but the subsequent low replacing it will be small and weak. Thus
only moderate trade winds will continue over the area. High
pressure will replace this low north of us on Sunday night. Low
pressure will develop in the west central Atlantic to diminish
gradients over the forecast area and winds will diminish Tuesday
and Wednesday. At the same time precipitable water values will
drop owing to the drier characteristic of the air out of the
central Atlantic in the northeasterly flow.

Mid and upper levels are mostly dry, although low-level moisture
intrudes into the mid levels a little on Sunday. Although there
are upper-level trough passages on Saturday and late Monday they
will have only a limited affect on conditions in the lower levels.

&&

.AVIATION...Mainly VFR conditions are expected across all
terminals during the next 24 hours. Occasional VCSH expected
across TIST/TISX terminals between 05/09-18Z. Afternoon convection
will result in VCSH across TJSJ/TJMZ/TJBQ around 05/14-23Z. This
could result in brief MVFR conditions. Light and variable winds
expected through 05/14Z, increasing to 10-15 kt from east-
southeast afterwards with gusts up to 25 knots and sea breeze
variations. Maximum winds W 45-55 kt btwn FL330-430.

&&

.MARINE...Although seas approach 7 feet in the western local outer
Atlantic waters on Friday night, small craft advisories are not
expected. Current models indicate that conditions will greatly
improve next week. Vigorous lows in the northern Atlantic will
bring northerly swell of 2 to 4 feet from time to time with the
best swell on Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 72 83 74 / 40 20 20 20
STT 84 73 83 74 / 40 10 10 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
424 AM AST Thu Mar 7 2019

.SYNOPSIS...Fragments of moisture embedded in the trade winds
will continue to move across the forecast area at times. Although
mid to upper levels will remain significantly dry, shower
development is expected each day, particularly along and downwind
from the Cordillera Central. An east to east-northeast wind flow
will hold through Saturday, backing to the northeast as a surface
high pressure enters and moves across the western Atlantic by
Sunday. A relatively dry weather pattern is expected as the
frequency of drier air patches increases early next week.

&&

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

A weak mid level trough across the eastern Caribbean and an upper
level jet will aid in the development of afternoon showers over
western PR through the short term period. A front is expected to
stall and remain north of the region, but a light to moderate east-
northeast steering wind flow is expected to prevail through at least
Friday. Model guidance suggest that the best available low level
moisture and instability is expected today and on Saturday. Drier
air is expected to fill briefly on Friday across the area. For
today, an area of cloudiness and showers will continue to move from
the U.S. Virgin Islands into the eastern sections of PR through the
morning hours. Under the influence of the the mid level trough and
the surge of moisture from the east, scattered to locally numerous
showers are expected to develop over sections of the Cordillera
Central and west/southwest PR. Showers could linger through the
evening hours. Urban and small stream flooding is possible with this
activity.

Drier air is expected to fill overnight and through Friday from the
east and afternoon showers should be limited to the western sections
of PR. On Saturday, winds are expected to increase somewhat and turn
more from the east as a surface high pressure moves into the western
Atlantic. Also, at upper levels a trough is to establish across the
northeastern Caribbean and low level clouds and passing showers are
forecast to increase across the Caribbean waters. This surge in
moisture will enhance afternoon convection across mainland PR once
again and as winds increase, streamers with light rainfall
amounts are expected to develop off the U.S. Virgin Islands.

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

Model suggests that a surface high pressure will build over the
western Atlantic and then drift southwestward into the Bahamas
region until it dissipates by Wednesday. In the meantime, a broad
surface high pressure will move off the east coast of the United
States into the western Atlantic. The combination of these
features will maintain a moderate to fresh northeast wind flow
across the region. Although patches of low-level moisture,
associated to the remnants of a frontal boundary, are expected to
move in on Sunday into Monday, a mass of relatively drier air will
quickly infiltrate and dominate the local weather conditions late
Monday night through at least Thursday. Afternoon convection, if
any, could develop over the interior and southwestern Puerto Rico
each day. However, the presence of a ridge aloft centered over
the western Atlantic along with drying upper level conditions and
a strong wind cap will suppress deep convection and limit
significant rainfall accumulations across the local islands.


&&

.AVIATION...Mainly VFR conditions are expected to prevail through
the forecast period. However, SHRA over west/southwest PR should
cause tempo MVFR conditions at TJPS/TJMZ btw 16z-22z. ENE winds at
10-15 kt will prevail with sea breeze variations after 14z across
the south/west coast of Puerto Rico.


&&

.MARINE...Tranquil marine conditions are expected today across the
regional waters with seas up to 5 feet and east winds up to 15
knots. A weak northerly swell will invade and spread across the
regional waters by Friday and continuing through the weekend. Then,
a surface high pressure will build north of the region,
generating a moderate to fresh northeast wind flow by Sunday. Both
events will require small craft operators to exercise caution due
to increased seas up to 6 feet and/or winds up to 20 knots.

A moderate risk of rip currents will continue for beaches along
the north and southeast coast of Puerto Rico, as well as a few
beaches in Culebra and most beaches in Vieques and Saint Croix.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 73 85 72 / 20 10 10 40
STT 84 73 83 74 / 50 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
512 AM AST Fri Mar 8 2019

.SYNOPSIS...Fragments of moisture embedded in the trade winds
will continue to move across the forecast area at times. Although
mid to upper levels will remain significantly dry, afternoon
convection is expected each day. An east to east-northeast
wind flow will hold through Saturday, increasing and turning from
the northeast as a surface high pressure moves and builds across
the western Atlantic by Sunday through next week. A better chance
for showers can be expected on Monday and Tuesday as a mid-level
through establishes northwest of the region.


&&

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

Dry air between 800mb-400mb will promote fair weather conditions
across the islands today. However, diurnally induced afternoon
showers are expected to develop mainly over portions of western PR.
East wind flow is expected to prevail today and maximum temperatures
should reach the high 80s to low 90 across some sections of southern
PR. Elsewhere, temperatures should range from the mid 70s across the
higher elevations to the mid 80s. An area of cloudiness and showers,
currently southeast of st. Croix that extends into the Leeward
islands is expected to stream across the region this evening and
continue across the region through Saturday.

Although the bulk of moisture is expected to remain across the
Caribbean waters, an upper level trough across the northeastern
Caribbean should enhance showers across the USVI and eastern
sections of Puerto Rico through the morning hours, followed by
scattered afternoon showers across the rest of the area. A surface
high pressure is expected to build during the weekend across the
western Atlantic and promote a northeast wind flow as well
occasional passing showers across the USVI and the north/eastern
sections of PR. Diurnally induced afternoon showers are expected
once again on Sunday afternoon, mainly over portions of the interior
and southwestern PR.

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

Model suggests that a surface high pressure will spread
southwestward into the Bahamas region until it dissipates late
Tuesday night. In the meantime, a broad surface high pressure
will move off the east coast of the United States into the western
Atlantic and build north of the region. The combination of these
features will maintain a moderate to fresh northeast wind flow
across the region. Although patches of low-level moisture,
associated to the remnants of a frontal boundary, are expected to
move in through late Monday night, a mass of relatively drier air
will quickly infiltrate and dominate the local weather conditions through
at least Thursday morning. Afternoon convection could develop
over the interior and drift over southwestern Puerto Rico each
day with a better chance for showers expected on Monday and
Tuesday as a mid-level trough establishes to the northwest,
favoring divergence overhead. Unfavorable upper level conditions will
limit deep convection on Wednesday and Thursday, but the entrance
of a frontal boundary sinking from the north will enhance shower
development by Friday.

&&

.AVIATION...Mainly VFR conditions are expected to prevail through
the forecast period. However, SHRA over west PR btw 16z-22z may
cause tempo MVFR conditions at TJMZ. East winds will prevail btw 10-
15 kt with higher gusts and sea breeze variations after 14z.


&&

.MARINE...Small craft operators are urged to exercise caution across
the outer Atlantic waters and coastal waters south of Puerto Rico
due to seas up to 6 feet and winds up to 20 knots. Elsewhere,
tranquil marine conditions with seas up to 5 feet and winds up to
15 knots will prevail today. The arrival of a northerly swell
will spread choppy conditions across portions of the coastal
waters north of Puerto Rico and local passages this evening and
continuing on Saturday. On Sunday, winds are to increase and turn
from the northeast as another surface high moves into the western
Atlantic and builds north of the region. This will generate
small craft advisory conditions by Sunday into early next week,
particularly across the Atlantic waters and local passages.

A moderate risk of rip currents will continue for most of the
local beaches today. However, the risk will elevate to high for a
few beaches along the northwest and north central coast of Puerto
Rico this evening and late tonight, respectively. Coastal marine
conditions are to improve by Sunday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 83 74 / 30 50 50 30
STT 84 73 83 73 / 30 50 50 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
530 AM AST Sat Mar 9 2019

.SYNOPSIS...A surface trough moving across the islands will
continue to result in cloudiness and showers through the day.
An upper level trough is forecast to continue north/northeast of
the region through early next week. Drier mid level air is
expected to gradually filter on Sunday and continue through next
week, resulting in fair weather conditions. A surface high
pressure building over the western Atlantic will promote a
northeast wind flow through next week. The remnants of an old
frontal boundary are expected to move across the islands by
Monday.

&&

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

Mostly cloudy skies and frequent passing showers prevailed across
the local islands overnight and early this morning. Radar estimates
indicated the highest rainfall accumulations across the east and
southeast coastal areas of Puerto Rico. Rainfall totals between one
and two inches were observed across these areas. Winds were from the
east southeast at 15 mph or less.

Although an upper level short wave trough will move away from the
forecast area by this afternoon, an induced surface trough and
associated low level moisture will continue to prevail across the
forecast area through late tonight. As a result, expect passing
showers across the US Virgin Islands and the east and southeast
coastal areas of Puerto Rico through the morning hours followed by
scattered to numerous showers developing over the western interior
and western Puerto Rico in the afternoon as the aforementioned
surface trough combines with local effect and diurnal heating. As
this feature moves away late tonight into early Sunday morning, a
drier air mass is expected to encompass the forecast area with a
generally fair weather pattern. The expected east northeast wind
flow, however, will bring passing showers across the northern US
Virgin Islands as well as the northern slopes of Puerto Rico on
Sunday. The chance for shower activity is expected to slightly
increase on Monday as the wind flow pushes the remnants of an old
frontal boundary across the local isles.

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

A surface ridge over the western Atlantic will maintain a
northerly wind flow through the long term period. An upper level
trough is expected to remain northeast of the region on Tuesday
and drier air will gradually fill across the area. A deep polar trough
is forecast to exit the east coast of USA by midweek but it is
expected to remain far northeast of the region. However, model
guidance suggest that an associated weak cold front could move
across the islands between Thursday and early Friday. In general,
a northeast steering wind flow and dry air aloft should result in
fair weather conditions with the exception of light passing
showers across the Atlantic waters and coastal areas of the
islands, followed by shallow afternoon convection over portions of
the interior/southwestern quadrant of PR.


&&

.AVIATION...Periods of MVFR conds will remain possible through at
least 09/22z at PR and USVI terminals in -SHRA/SHRA. BKN-OVC lyrs to
continue nr FL025...FL050...FL080. ESE winds 10 to 15 knots with
higher gusts in shower activity. Across the Leeward terminals,
mostly VFR with VCSH possible.


&&

.MARINE...Northerly swell will continue across the Atlantic waters
and passages today, seas up to 6 feet and east to northeast winds
at 15-20 knots are expected across most of the regional waters
today. Therefore, small crafts should exercise caution. A surface
high pressure will build across the western Atlantic by early next
week, this will increase winds and maintain choppy seas across the
Atlantic waters. There is a high rip current risk in effect for
the northern beaches of Puerto Rico through Sunday morning.


&&

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