Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
543 AM AST Sat Mar 30 2019

.SYNOPSIS...A surface low north of the region and associated
front to the west and north of the forecast area, will continue
to promote instability, low level moisture convergence and light
southeasterly winds through the rest of the weekend. A mid level
ridge will promote drier air and more stable conditions during the
workweek.


&&

.SHORT TERM...Saturday through Monday...

The combination between a surface high pressure over the Central
Atlantic and a low with it associated frontal boundary off to the
north of the islands will maintain a southeasterly wind flow across
the region through at least Sunday. The frontal system will continue
to slowly drift across the Atlantic until it dissipates. This
weather pattern will promote the arrival of patches of moisture
across the islands. In addition, a sub-tropical jet associated with
a mid-to-upper-level trough will aid in afternoon convection along
and to the north of the Cordillera Central and downwind from El
Yunque each afternoon. The U.S. Virgin Islands and the southern
sections of Puerto Rico can expect mostly sunny skies with a few
passing showers during the overnight and morning hours. A similar
weather pattern will prevail on Sunday.

For Monday, the easterly winds are forecast to return as a migratory
high pressure moves from the eastern US into the western Atlantic.
At upper levels, a mid to upper-level ridge will build aloft
reinforcing the trade wind inversion. Moisture will slowly erodes and
temperatures are likely to reach the mid to upper 80s along the
northern sections. Under this pattern, patches of low-level moisture
embedded in the trade winds will move in from time-to-time.

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

Mid level ridge is forecast to build from the western Caribbean
and move over the forecast area during the end of the week. This
will promote dry air and stable conditions aloft. An upper level
westerly jet is expected to remain north of the islands across the
Atlantic. Low level moisture will be capped at 700 MB or less and
peaks on Wednesday and Saturday due to weak surface troughs
moving from the east. In general, diurnally induced afternoon
showers are expected each day over the interior and western
sections of PR and rainfall amounts should be light to moderate.
Passing trade wind showers are expected through the long term
period across the regional waters and they could move at times
across the U.S. Virgin Islands.



&&

.AVIATION...VFR conditions expected to prevail across all terminals
thru 30/16Z. Then, -SHRA/SHRA are expected to develop across the
mountain range of Puerto Rico and downwind from El Yunque. This
activity could affect TJBQ/TJMZ and possibly over TJSJ. Calm to
light and variable winds will continue thru at least 30/13z,
becoming from the southeast around 10 knots with sea breeze
variations after 30/13z.


&&

.MARINE...Fading northerly swell will continue to result in a
high rip current risk across the beaches of Rincon and northern
Puerto Rico. Small crafts should exercise caution due to seas up
to 6 feet across the Atlantic waters. Elsewhere, seas should range
between 3-5 feet. Light southeasterly winds will prevail through
the rest of the weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 87 75 / 30 30 30 20
STT 85 74 85 74 / 20 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
413 AM AST Sun Mar 31 2019

.SYNOPSIS...A surface low pressure system and associated frontal
boundary will promote moisture converge as well as a weak low
level flow across the local islands. This will favor long-lived
and slow-moving showers this afternoon. Although a mid level
ridge will promote a drier and more stable weather pattern on
Monday and continuing through the workweek, patches of low-level
moisture will enhance cloud coverage and shower activity
enhancement across the region from time-to- time, particularly
over portions of the interior and western Puerto Rico each
afternoon.


&&

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

Deep layer low pressure system centered near 30N 65W is supporting a
frontal boundary that extends into the northeast Caribbean this
morning. This trough pattern across the Western Atlantic and the
associated front is promoting moisture converge as well as a weak
low level flow across the local islands. With a weak steering flow
and a fairly unstable atmosphere, showers will cluster over the
Cordillera Central early in the afternoon, drifting to the west and
southwest coastal plains late in the afternoon. An upper level
trough will move over the region later today, enhancing somewhat the
showers activity across the interior of PR. In contrast, little or
no rainfall is anticipated for the U.S. Virgin Islands.

For Monday and Tuesday, a mid to upper level ridge will start to
develop across the eastern Caribbean. At the same time, the frontal
boundary will gradually dissipates, resulting in less shower
coverage across the local islands. Under the influence of the ridge
aloft, the overall moisture will decrease below normal levels as mid
level moisture drops significantly. On Monday, the afternoon showers
will likely cluster over southwestern PR while the focus of the
showers will drift to western PR on Tuesday.


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

A moderate to locally fresh easterly wind flow is expected
through Wednesday afternoon, before turning from the northeast
late Wednesday night and holding through at least Friday afternoon
as a surface high pressure moves off the east coast of the United
States across the western Atlantic and north of the region. As
this high continues to move eastward into the north central
Atlantic, winds will become fresh to locally strong while veering
from the east through the weekend. Despite changes in the flow, a
mainly seasonal weather pattern is expected during the long-term
forecast period influenced by intermittently patches of dry/moist
air moving across the region. Along with the patches of moist
air, cloud coverage and shower activity enhancement is expected
over the area, particularly across the interior and western Puerto
Rico each afternoon hours supported by diurnal heating and local
effects. By Wednesday and continuing through the long-term period,
global models suggest that a mid-level ridge will hold and build
over the region, supporting a strong trade wind cap and drier
conditions aloft while suppressing deep convection and limiting
rainfall accumulations resulting from any shower activity.


&&

.AVIATION...VFR conditions will likely prevail across all terminals
thru the forecast period. However, SHRA will develop across the
mountainous areas in the afternoon. VCSH can`t ruled out near TJMZ
and TJPS as weak flow may drift some of the SHRA closer to the
terminals. SE to NE winds of 10 kts are forecast below FL100.


&&

.MARINE...Tranquil coastal and marine conditions are expected
across the region today. That is due to seas at or below 5 feet
and east to southeast winds up to 10 knots. As for the coastal
areas, a moderate risk of rip currents continues for beaches along
the north coast of Puerto Rico, Culebra and Saint Thomas.
Elsewhere, a low risk of rip currents is expected. Local conditions
are forecast to deteriorate by late Thursday with the arrival of
a northerly swell and a fresh to locally strong low-level wind
flow.


&&

.FIRE WEATHER...As patches of low-level moisture continue to move
across the region in response to the passage of a dissipating
frontal system, relatively high moisture content and enhanced
shower activity are expected under a light east to southeast low-
level wind flow. Although recent observation continue to show
KBDI values above critical thresholds between 640 and 720, the
current forecast calls for conditions that will minimize the fire
threat. Thus, low fire danger conditions are expected today.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 76 86 76 / 30 20 30 40
STT 85 74 85 74 / 30 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
458 AM AST Mon Apr 1 2019

.SYNOPSIS...Mid to upper level high pressure will continue to
dominate through at least midweek. At the surface, remnants of an
old frontal boundary will keep the moisture levels near normal.
Therefore, showers are expected to develop each afternoon across
portions of the south and west Puerto Rico. Winds will increase
late in the week, enhancing the trade winds showers across the
local region Friday into the weekend.

&&

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

A mid and upper level ridge will prevail across the local area.
Also, a weak surface high pressure across the western Atlantic will
dissipate and a surface low pressure will build in its place as it
moves north across the eastern seaboard of the US. This means that
the local winds will be from the ENE today and gradually turn
easterly into Tuesday and Wednesday. The available moisture will be
near normal and the combination of the available moisture with the
diurnal heating and the local effects will cause showers to develop
in the afternoon across different sections of Puerto Rico depending
on the mean wind flow. This afternoon, the relatively light ENE
winds means that the afternoon showers are expected to be
concentrated in the southern slopes and southern coastal areas as
well as portions of the central and the eastern interior of PR.
Elsewhere, including the USVI, isolated to locally scattered showers
are expected. As far as temperatures go, the eastern and northern
sections of PR and across the USVI, max temps should be in the mid
to upper 80s, while the western and southern sections of PR could
observe temps up to around 90 degrees.

Since the local winds are expected to turn more easterly on Tuesday
and Wednesday, the overall rain pattern will remain typical with a
slight chance of showers across the local waters, USVI and eastern
PR in the overnight and morning hours, then more significant showers
developing in the afternoon across western PR, mainly due to local
effects.

.LONG TERM...Thursday to Monday...

Mid level ridge holds across the Caribbean Basin trapping most of
the moisture below 700 MB. This dry and stable air mass aloft should
limit the vertical development of showers the rest of the week.
However, surface winds will increase across the region as a strong
high pressure system moves over the Western Atlantic late
Thursday into Friday. A wind surge will approach from the east on
Friday enhancing the moisture convergence across the islands.
Therefore, the frequency of trade wind shower will likely increase
Friday into the weekend as low level moisture transport is maximized
under a fresh northeasterly flow. Also a couple of short-wave
troughs will stream over the northeast Caribbean during the
weekend, weakening the aforementioned mid-level ridge.

&&

.AVIATION...VFR conditions will prevail across all terminals through
01/16Z. SHRA will develop across the mountainous areas thereafter.
VCSH expected for TJMZ and TJPS, but TEMPO MVFR conds are possible
at TJPS later in the afternoon. Due to some uncertainty TEMPO in not
in TAF but SHRA/+SHRA at TJPS appears to be possible. E to ENE winds
at 10-15KT are expected today with some gusts and sea breeze
variations.

&&

.MARINE...Relatively tranquil conditions will prevail over the
next few days. Marine conditions are forecast to deteriorate by
late Thursday as wind increases and a northerly swell arrives to
the local islands. Small craft advisories are possible from Friday
into the weekend as the swell will combine with the wind waves
producing confused seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 88 75 / 20 20 10 10
STT 86 76 85 76 / 30 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
455 AM AST Tue Apr 2 2019

.SYNOPSIS...Mid to upper-level ridge will continue to hold
during the next several days, preventing the development of deep
and organized convection across the area. Patches of low-level
moisture, however, will move across the area and will result in
afternoon showers across the western half of Puerto Rico each day.
A surface high pressure will build and spread across the Atlantic
basin by the latter half of the week into the upcoming weekend,
increasing the trade wind flow.

&&

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

Surface high pressure moving into the western Atlantic Ocean will
reinforce the easterly trade winds in the local area. As the high
moves east into the north central Atlantic Wednesday it will become
strong. A second high moving off the coast of South Carolina behind
a strong low that moved northeast will maintain moderate to fresh
trade winds over the area. Patches of moisture will regularly be
carried through the area. Although forecast soundings indicate that
capping inversions will be somewhat higher this week than last week,
most convection will still be unable to grow through 18 kft, except
during the warmest portions of the afternoons in western Puerto
Rico. Another limiting factor will be the very dry air between 700
and 300 mb (approx 10-32 kft) that will persist beyond Friday.
Nevertheless, considering past performance under similar conditions,
this will not prohibit very localized maxima of 2 to 4 inches from
occurring as they did on Monday under persistent cumulus streams.
But, overall amounts are expected to be less than one quarter inch
and favor western and interior Puerto Rico each day.

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

The aformentioned mid to upper-level ridge will continue to hold
through much of the long term period. This will continue to trap
moisture below 700 mb. Therefore, deep and organized convection is
not expected. A surface high pressure is expected to build across
the Atlantic basin during the upcoming weekend and hold through
early next week. This will increase the low-level flow and also
the frequency of trade wind shower activity. Under this weather
pattern, passing showers can be expected across portions of the
eastern half of Puerto Rico and the USVI during the overnight and
morning hours followed by locally and diurnally induced showers
across western PR during the afternoon hours.

&&

.AVIATION...VFR conditions will prevail across TNCM/TKPK thru
03/00z and all other terminals through 01/16Z. SHRA will develop
across wrn/interior PR 02/16-03/00Z. LCL MVFR conds at TJMZ/TJBQ
02/18-21Z in +SHRA. E to ENE winds at 10-15KT are expected today
with some gusts and sea breeze variations. Max winds W 50-60 kt btwn
FL380-480.

&&

.MARINE...Typical marine conditions are expected to continue over
the next few days with seas ranging between 3 and 5 feet. Easterly
winds 10 to 15 knots will prevail through midweek, increasing to
15-20 knots the second part of the week. At the same time, a moderate
northerly swell will reach the regional waters increasing the seas
to around 5-7 feet from Thursday through at least Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 75 87 75 / 20 20 40 50
STT 85 76 86 74 / 20 20 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
458 AM AST Wed Apr 3 2019

.SYNOPSIS...Limited moisture advection should reduce the shower
coverage across the islands through Friday. Conditions will become
more favorable for showers during the weekend and early next week
as a couple of mid-upper level troughs enhance the moisture transport
across the eastern Caribbean.

&&

.SHORT TERM...Today thru Friday...

A drier and stable air mass will spread across the forecast today
through Thursday with moderate east northeast low level winds
expected to prevail. Early morning passing showers will be limited
to parts of the north and east coastal areas...followed by afternoon
showers expected to develop mainly over parts of central and west to
southwest sections of Puerto Rico. Afternoon shower activity should
however be of short duration as the prevailing low level steering
winds should increase throughout the day. Elsewhere mostly sunny and
fair weather skies should prevail through at least Thursday.

A mid to upper level ridge will hold across the forecast area
through most of the forecast period, but is forecast to slightly
erode by late Friday due to the approach of a short wave trough. In
the low levels, east northeast winds will prevail and gradually
increase Thursday and Friday as a surface high pressure ridge builds
and reestablishes across the west and central Atlantic.

Although a continued decrease in the layered precipitable water is
forecast for the next day or two, the prevailing moderate easterly
wind flow should continue to bring occasional patches of shallow low
level moisture across the region. Therefore, expect passing early
morning showers over the coastal waters and mainly northeast sections
of the islands, followed by limited shower development mainly over
west and southwest Puerto Rico during the afternoons. Elsewhere,
mainly fair weather and sunny skies with only a slight chance of
isolated showers mainly down wind of the adjacent islands including
the U.S. Virgin Islands.

By late Friday, the aformentioned mid to upper-level ridge will
slightly erode and low level east to northeast trade winds should
continue to increase. This will allow more frequent passing trade
wind moisture and a better chance for afternoon showers over parts
of western Puerto Rico. However, expect the trade wind cap to hold
and therefore deep and organized convection is still not anticipated
during the period.

.LONG TERM...Saturday to Wednesday...

Mid level ridge will linger through Saturday, then a couple of
short-wave troughs stream across the Caribbean Basin Sunday into
early next week. At surface, strong high pressure north of the
area will induce brisk easterly winds during the weekend. This
surge in the trade winds will maximize the moisture convergence
across the region on Saturday. As a result, environmental conditions
will support the development of showers most of the weekend. Good
upper level dynamics due to the proximity of the 250mb jet maxima
may result in a few thunderstorms during the weekend.

Early next week, the elevated trade wind cap will continue to
promote additional moisture transport across the northeast
Caribbean. Mid to upper troughs moving eastward over the western
Atlantic will likely result in unstable conditions through mid-
week next week.

&&

.AVIATION...VFR cond durg entire prd. Isold SHRA ovr coastal
waters and en route btw islands. SCT lyrs nr FL025...FL050...SKC
ABV. L/lvl wnds fm E-ENE 5-15 knots BLO FL200 bcmg fm W and incr
w/ht ABV. Sfc wnds LGT/VRB bcmg mainly ENE 15 to 20 knots with
higher gusts and sea breeze variations after 03/14z.

&&

.MARINE...Surface winds are forecast to increase for the second
part of the week as a surface high pressure establishes across the
western Atlantic. A moderate northerly swell will reach the local
Atlantic waters and Caribbean Passages on Friday and continue
through the weekend. Therefore, a high risk of rip currents and
Small Craft Advisories are probable over the next couple of days.

&&

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

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
504 AM AST Thu Apr 4 2019

.SYNOPSIS...
The mid to upper level high pressure ridge will continue to build
across the west Atlantic and spread further eastward across the
region through the end of the work week. This will strengthen the
local trade wind cap inversion which in turn will suppress organized
convection. Surface high pressure will also continue to strengthen
its hold across the Atlantic to maintain a fairly tight local pressure
gradient and moderate to strong easterly winds across the forecast
area. This overall pattern should limit the pooling of moisture across
the region for the rest of the work week. Occasional patches of shallow
trade wind moisture will however continue make its way across the area.
A better chance for enhanced shower development and instability aloft
is forecast for the weekend as an upper level trough is expected to
move across or just north of the region.

&&

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

A surface high pressure building across the Atlantic waters will
produce a moderate to locally fresh easterly wind flow across the
northeast Caribbean. Under this wind flow, patches of low level
moisture will reach the local islands from time to time. A ridge
pattern aloft will limit vertical development, therefore, no
thunderstorm activity is expected at this time. Under this weather
pattern, continues to expect overnight and early morning passing
showers across the local waters, the U.S. Virgin Islands and the
north, east and interior sections of PR each day. The combination of
local effects, sea breezes and diurnal heating will aid in the
development of showers along and southwest of the mountain range, as
well as downwind from the U.S. Virgin Islands each afternoon.
Overall, isolated rainfall amounts of up to an inch can be expected
along portions of the western interior and southwestern Puerto Rico
with the strongest activity each afternoon. Elsewhere, mostly fair
weather conditions are expected.

The mid to upper-level ridge is forecast to slowly erode during
the weekend as a short wave trough approaches from the west. Under
this pattern, an increase in shower activity is possible for the
weekend.

.LONG TERM...Sunday through Thursday...
The mid to upper level ridge is to continue to erode on Sunday as
the short wave trough moves across the southwest Atlantic and
lifts across or just north of the region accompanying a subtropical
jet max. This in turn will increase divergence and instability
aloft at least through Sunday. The weakening ridge aloft will also
erode the trade wind cap inversion and consequently support better
local level convergence and instability. This pattern will favor
a better chance for increased early morning shower activity as
well as enhanced afternoon convection across the islands at least
through Sunday.

Periods of moderate to heavy rainfall will therefore be possible
on Sunday particularly over parts of the central and west sections
of Puerto Rico where the local forcing should be strongest with
the shower activity steered by the moderate easterly trade winds.
A gradual improvement is expected by Monday and through mid week
as the mid to upper level ridge will reestablish across the region
and the trade wind inversion strengthens once again. This will
result in the erosion of trade wind moisture across the forecast
area. Local winds are to also become more southeasterly by Wednesday
and Thursday as the Atlantic high pressure shifts farther eastwards
and a weak surface trough develops near to or across the region.

&&

.AVIATION... VFR conds expected thru most of the forecast period.
Scattered to numerous SHRA will continue ovr coastal waters and en
route btw the islands. Some of them will move inland to affect the
terminals of E-PR/USVI and the Leeward Islands. SHRA are forecast to
develop over the Cordillera Central between 04/16-23z and may affect
TJPS and TJMZ. Winds will continue from the NE at 5 to 10 mph
increasing at 15 to 20 knots with higher gusts after 04/13z.


&&

.MARINE...Moderate to fresh easterly winds of 15-20 knots with
occasionally higher gusts will prevail across the regional waters
during the next few days. A small northerly swell will spread
across the local Atlantic waters and Caribbean Passages during
the day. These conditions will create choppy and hazardous seas,
requiring small craft operators to exercise caution across most of
the local waters. By Friday and continuing through the weekend,
another northerly swell of moderate intensity will reach the
regional waters. As a result, Small Craft Advisories will likely
be required.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 85 73 / 30 30 30 40
STT 86 75 86 74 / 10 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
517 AM AST Fri Apr 5 2019

.SYNOPSIS...
A surface high pressure will continues to promote a trade wind
flow across the northeast Caribbean. As a result, trade wind
showers will affect the local waters, and the windward sections
of Puerto Rico and the U.S. Virgin Islands. A trade wind
perturbation will reach the archipelago of PR and the USVI this
afternoon. Another surface high will exit the Eastern Seaboard of
the U.S. and moves eastward across the Atlantic Ocean through
early next week. A mid to upper-level ridge will hold through at
least Saturday, when a short wave trough is forecast to swing by
from the west.

&&

SHORT TERM...Today through Sunday...

A ridge aloft will continue to suppress the development of organized
and deep convection across the forecast area during the next several
days. At the surface, a broad high pressure across the Atlantic
basin will continue to produce a moderate easterly wind flow
throughout the short-term period. This will serve to produce breezy
conditions across the forecast area, especially from the mid-morning
into the early evening hours.

For today, some brief showers may affect eastern portions of PR
during the early to mid morning hours. This will be followed by the
development of some afternoon showers across western PR due to
daytime heating and local effects. A low-level trade wind
perturbation, located near the leeward islands, is expected to move
across the USVI and the eastern half of PR later this evening into
the overnight. This will result in more numerous passing showers
across these areas during this time period. On Saturday, low-level
moisture associated with the low-level trade wind perturbation will
linger across PR. Therefore, expect some brief morning showers
across the eastern half of PR followed by the development of showers
across western PR during the afternoon hours due to daytime heating
and local effects.

A subtropical jet maxima near 250 mb is expected to move just north
of the area on Sunday. This will serve to increase the divergence
aloft. In addition, the low-level moisture will increase. As a
result, more widespread showers are expected across the forecast
area. Scattered showers are expected across portions of the USVI and
eastern PR during the morning hours, extending into the western half
of PR during the afternoon hours.

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

A mid level ridge will remain in place through the long term
period. This mid level feature will aid in dry air promoting a
trade wind inversion across the region. However, patches of low
level moisture will continue to promote trade wind showers across
the windward sections during the night and early morning hours
followed by afternoon convection across the western sections of
the islands. In addition, surface winds are forecast to veer from
the east-southeast Tuesday through the end of the work-week as
the Atlantic high pressure shifts farther eastwards.

&&

.AVIATION...
An area of cloudiness and sct SHRA just east of the leeward
islands will result in BKN cloud layers and VCSH across TNCM and
TKPK between 05/14z and 05/22z, resulting in brief MVFR
conditions. SHRA are expected across western PR between 05/16z and
05/22z. This may affect mainly TJMZ terminal and result in MVFR
conditions at times. Otherwise, VFR conditions will prevail. Winds
will continue from the E at less than 10 knots through 05/12z,
increasing to 15 to 20 knots with higher gusts and sea breeze
variations after 05/13z.

&&

.MARINE...
A moderate to fresh easterly wind flow will prevail during the next
few days as a high pressure ridge builds north of the region. A
northerly swell will spread across the local waters throughout the
weekend. As a result, mariners can expect increasing seas between
5 and 7 feet across the Atlantic waters and Caribbean Passages by
late this afternoon. The combination of increasing trade winds
and the continued swell action will generate choppy and hazardous
seas across the regional waters. Therefore a small craft advisory
is in effect from this evening into the weekend. Marine conditions
are forecast to improve by early next week.

For beach goers, a high rip current risk continues in effect for
beaches along the northwest to northeast coast of Puerto Rico.
The high risk will expand across the northern beaches of Culebra
this evening into Saturday. Elsewhere, a moderate risk of rip
currents remains in place for most local beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 73 / 40 60 40 40
STT 87 76 85 75 / 50 50 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
512 AM AST Sat Apr 6 2019

.SYNOPSIS...
A broad surface high pressure across the Atlantic Ocean will
promote an advective pattern across the region. A mid to upper
level ridge will limit the vertical development across the islands
through much of the forecast period. However, passing showers
will affect the U.S. Virgin Islands and the eastern half portion
of Puerto Rico during the morning, followed by shallow afternoon
activity along and west of the Cordillera Central each day.

&&

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

Not much change to the overall synoptic pattern expected during
the next several days as a ridge aloft will continue to hold
across the area. This will suppress the development of deep and
organized convection. At the surface, a broad surface high
pressure situated across the Atlantic basin will continue to
promote a moderate easterly wind flow throughout the weekend. This
will generate breezy conditions across the area at times,
especially from the mid-morning into the early evening hours.

For today, a surge in low-level moisture associated with a low-level
trade wind perturbation will continue to generate areas of showers
across the region. Through the mid-morning hours, brief scattered
showers are expected mainly across the eastern half of PR. This will
then be followed by the development of showers across western PR
this afternoon as the available low-level moisture will combine with
daytime heating and local effects. Across the USVI, only a few
showers are expected throughout the day. A drier air mass will then
move overhead by tonight, promoting mainly fair weather conditions.

On Sunday, a subtropical jet maxima at 250 mb will be situated
northeast of region. This will put the region under the divergent
side of the jet. Therefore, a greater coverage in shower activity is
possible. However, given that a ridge will continue to be present at
the 500 mb level and precipitable water values are expected to run
in the near to slightly below normal range, only expecting light to
moderate rainfall activity at this time.

Another surge in low-level moisture is expected Sunday night into
Monday. This will promote trade wind showers across portions of
eastern PR, the USVI, and surrounding waters during the overnight
and morning hours. This will then be followed by more enhanced
showers across western PR during the afternoon hours.

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

A mid level ridge will remain in place through the long term
period. This mid level feature will promote a trade wind
inversion through much of the forecast period. A broad surface
high pressure across the Atlantic Ocean will promote an east to
southeast wind flow across the islands through at least Friday.
This pattern will aid in a seasonal advective weather pattern
driven by occasional patches of shallow moisture reaching the
forecast area each day. Then, diurnal and locally induced
afternoon showers will develop along and west of the mountain
range of Puerto Rico.

Model guidance are suggesting a mid to upper level trough moving
near the region by next weekend, which could increase the chance
for enhanced shower development and instability aloft. However,
the confidence is low due to how far in the forecast time it is.

&&

.AVIATION...Mainly VFR conditions expected across all terminals
throughout the period. SHRA expected across western PR between
06/16z and 06/22z, affecting TJMZ and TJBQ. Some brief MVFR
conditions cannot be ruled out. Winds will continue out of the E
below 10 kts through 06/12z, increasing to 15 to 20 knots with
higher gusts and sea breeze variations after 06/13z.

&&

.MARINE...
A northerly swell will continue to move across the Atlantic Waters
and Caribbean passages. This swell combined with fresh trade
winds will generate hazardous marine conditions across these
waters. Mariners can expect seas between 5 and 7 feet through at
least Sunday morning. As a result, small craft advisories are in
effect for these waters. Elsewhere, choppy seas up to 6 feet are
expected through at least early next week. Winds will continue
from the east at 10 to 20 knots with higher gusts. Marine
conditions should improve by next week as model guidances are
suggesting.

For the beach goers, the northerly swell is producing a high risk
of rip currents along the northwest to northeast coast of Puerto
Rico, Culebra and St Croix. A moderate risk remains in place for
most of the remaining local beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 87 74 / 50 20 40 50
STT 85 74 85 75 / 20 20 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Sun Apr 7 2019

.SYNOPSIS...A mid to upper-level ridge will continue to hold
across the area during the next several days. This will suppress
the development of deep and organized convection. Patches of low-
level moisture, however, will continue to move across the area
from time to time. This will result in some brief showers during
overnight and morning hours across portions of eastern PR and the
USVI followed by additional showers across western PR during the
afternoon hours. Overall, significant rainfall activity is not
expected throughout the forecast period.

&&

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

Tranquil weather conditions with little to no shower activity
prevailed overnight. Then, a surge of moisture approached the
islands increasing shower activity across the local waters and some
of them moved inland over the windward sections of Puerto Rico and
the U.S. Virgin Islands early this morning. Satellite imagery
depicted a surge of moisture approaching the islands. Passing clouds
and occasional showers will continue to move across the local
waters, the northern USVI and the north, south and east sections of
Puerto Rico through the morning hours. On the other hand, St Croix,
the interior and western sections of PR will have sunny to partly
skies with no shower activity.

A subtropical jet maxima at 250 mb northeast of the islands will
increase upper level divergence today, especially during the
afternoon hours. However, given the amount of subsidence at mid
levels associated with a mid-level high pressure, and TPW values
expected to run in the near to below normal range, no widespread
activity is expected during the afternoon. At this time, peak
rainfall accumulations should be focused over the interior and
western sections of Puerto Rico.

A climatological pattern will persist for the rest of the forecast
period. Therefore, surges of low level moisture will continue to
bring periods of passing showers across the windward sections
overnight and early in the morning. Then local effects and diurnal
heating will aid in afternoon showers across the interior and
western sections of the islands.

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

The aformentioned mid to upper-level ridge is expected to hold
across the area during much of the long-term period. This will
serve to enhance the subsidence in the mid to upper-levels of the
atmosphere. As a result, deep and organized convection is not
expected under this weather pattern. Patches of low-level
moisture embedded within the easterly trade wind flow will
continue to move across the area from time to time. This will
result in some brief showers across portions of eastern PR, the
USVI, and surrounding waters during the overnight and early
morning hours. This will then be followed by the development of
showers across interior and western portions of PR during the
afternoon hours as the available low-level moisture will combine
with daytime heating and local effects.

Surface high pressure and a ridge at 700 mb is expected to move
into the east-central and eastern Atlantic by the middle to
latter half of the work week. This will result in a southeasterly
low-level wind flow. As a result, temperatures across the
northern half of Puerto Rico may run above normal with some areas
surpassing 90 degrees for high temperatures.

&&

.AVIATION...Mainly VFR conditions expected across all terminals
throughout the period. Some brief passing showers will move in/near
TIST/TJSJ/TISX thru the morning hours. Then, SHRA expected to
develop across the interior and western PR between 07/16z and
08/00z, affecting TJMZ/TJBQ and the vicinity of TJPS. Some brief
MVFR conditions cannot be ruled out. Winds will continue from the E-
ESE at less than 10 knots, increasing at 15 to 20 knots with higher
gusts and sea breeze variations after 07/13z.

&&

.MARINE...A surface high pressure north of the area will continue
to result in moderate to fresh easterly winds between 15 and 20
knots across the area for today. This will result in choppy seas
of up to 6 feet across most of the regional waters. Therefore,
small craft operators are urged to exercise caution. Winds are
expected to gradually diminish during the next few days as the
surface high pressure moves farther east into the Atlantic.
Therefore, marine conditions are expected to improve.

For beachgoers, a high risk of rip currents is expected for the
northwest to San Juan and Vicinity beaches as well as for Cramer
Park in Saint Croix. A moderate risk of rip currents is expected
for most of the other beaches, except for those beaches along the
west coast of PR south of Rincon where the risk will be low.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 87 74 / 20 50 50 40
STT 86 75 84 74 / 10 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
503 AM AST Mon Apr 8 2019

.SYNOPSIS...
Patches of low-level moisture will continue to reach the islands
from time to time. However, a mid to upper-level ridge will
suppress any deep or organized convection through much of the
forecast period. Therefore, an advective pattern will dominate the
local weather conditions with local effects being the driving
factor with respect to any afternoon convection.

&&

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

Surface high pressure extending from the east central to the western
Atlantic will promote easterly winds today, but then gradually
shifting to southeast on Tuesday and Wednesday as a surface low
moves into the western Atlantic. Ridge in the mid and upper levels
expected to prevail over the local area. There is a trough in the
mid levels digging down into the western Caribbean and a mid level
high pressure to our east, which will keep the local islands until
the aforementioned ridge on Wednesday. The change to southeasterly
winds for Tuesday and Wednesday could cause the max temps to be near
or to reach the 90s across the San Juan metro area.

The overall moisture is expected to be near or below normal these
next few days, but the diurnal heating will combine with the local
effects to produce afternoon showers across western and central PR.
The latest high resolution guidance insists in afternoon showers,
some of then could be heavy at times. However, due to the limited
moisture and the lack of upper level feature to enhance instability,
the USVI are expected to observe mainly isolated to scattered brief
showers, except maybe the western sections of St Croix and St Thomas
as showers stream off the islands.

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

The lack of upper level dynamic is forecast to continue through
the long term period due to the mid-to-upper-level ridge. This
feature will promote subsidence and dry air in the mid to upper
levels. In the meantime, patches of low level moisture embedded
in the trades will continue to reach the local islands. However,
only shallow convection is expected under this weather pattern.
This will result in some brief showers across portions of eastern
PR, the USVI, and surrounding waters during the overnight and
early morning hours. In addition, surface winds are forecast to
continue out from the southeast through at least Friday. As a
result, temperatures across the northern half sections of Puerto
Rico may run above normal with some areas observing above or near
90 degrees for high temperatures.

&&

.Aviation...VFR conds expected through at least 08/16Z at the local
terminals. VCSH will continue as -SHRA pass by the local flying
area. Afternoon convection across interior and west PR will cause
VCSH at TJPS, TJMZ, and TJBQ at 08/17-22Z. TEMPO MVFR conds possible
at TJMZ during that time. Winds will be up to 10KT through 08/13Z,
increasing steadily thereafter to 15-20KT from the east with sea
breeze variations and occasional gusts.

&&

.MARINE...
Marine conditions will continue to improve across the local
waters through the end of the work-week. Mariners can expect seas
at less than 5 feet and winds around 15 knots. However, local
effects will aid in winds between 15 and 20 knots across the
coastal waters of south and north Puerto Rico during the afternoon
hours.

For the beach goers, the risk of rip current is moderate for most
of the local waters, except for the western sections of the
islands. These conditions should also hold through the workweek.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 87 75 / 40 30 30 20
STT 84 74 84 76 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
352 AM AST Tue Apr 9 2019

.SYNOPSIS...High pressure now located north of the area will
merge with a broad high pressure system centered over the eastern
Atlantic later today. This will shift surface winds toward a more
southeaterly component across the local region. Minor changes to
the weather pattern is anticipated through at least Thursday as
high pressure ridge dominates the eastern Caribbean limiting any
significant shower development.


&&

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

Surface high pressure extending from the east central to the western
Atlantic will continue promote easterly winds today, but mainly in
the morning as the local winds are expected to gradually shift to
ESE by this afternoon, then more SE by Wednesday and Thursday. This
is due to a surface that will move into the western Atlantic,
causing a change in the local wind flow. Latest guidance still
suggests that ridges in the mid and upper levels will prevail over
the local area for the next few days. There is a trough in the mid
levels digging down into the western Caribbean that is expected to
move east over the course of the next few days, however, this mid
level trough is expected to weaken as it moves east and by the time
it gets to the Hispaniola, the trough may have lifted a bit far
north and the impact would be weak for our area. So, at this time it
is still forecast for the afternoon showers over PR to be mainly
locally induced with the rest of PR and the USVI to be limited to
isolated to scattered brief showers.

The overall moisture is still forecast to be near or below normal
for the next few days. That said, the diurnal heating will still
combine with the local effects and produce afternoon showers across
western and northwestern PR. The USVI are expected to observe mainly
isolated to scattered brief showers, except maybe the western
sections of St Croix and St Thomas as showers stream off the islands.

.LONG TERM...Thursday through Tuesday...
High pressure wil maintain stable conditions from Wednesday
through Friday. This pattern is forecast to change late Friday
night as the old remanants of a cold front will move over the
local Atlantic waters. This feature will help increase the shower
coverage as moisture patches will move over the local forecast
area from time to time through Tuesday.

&&

.AVIATION...VFR conds expected through at least 09/16Z at the local
terminals. VCSH will continue as ISOLD -SHRA pass by the local
flying area. Afternoon convection across NW-PR will cause VCSH at
TJMZ and TJBQ at 09/18-22Z. TEMPO MVFR conds possible at TJBQ during
that time. Winds will be up to 10KT through 09/13Z, increasing
thereafter to around 15 KT from the east to ESE with sea breeze
variations and occasional gusts.


&&

.MARINE...As winds continue to slowly decrease today also local
marine conditions will continue to improve. Expect tranquil marine
conditions across all local waters from Wednesday to Friday.
Choppy marine conditions once again will prevail across the local
waters as winds are expected to pick up during the incoming
weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 88 75 / 40 20 20 40
STT 85 75 84 76 / 40 20 20 20

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
706 AM AST Wed Apr 10 2019

.SYNOPSIS...A moderate east to southeast low-level wind flow will
prevail through at least Friday as a surface high pressure continues
to moves further east into the east Atlantic. Another surface
high will move into the western Atlantic and build north of the
region, causing winds to increase and back to the east during the
weekend and continuing through early next week.

&&

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

Surface high pressure extending from the east central to the western
Atlantic and a surface low pressure entering the western Atlantic
will promote southeasterly winds today and for the next few days.
The southeasterly wind could cause an increase in daytime max
temperatures across some of the northern coastal municipalities of
Puerto Rico for the next few days, possibly reaching 90 degrees,
especially the north central and around the San Juan metro.

There is a trough in the mid levels digging down into the western
Caribbean that is expected to move east over the course of the next
few days, however, this mid level trough is expected to lift
slightly as it moves east, becoming part of a mid level low north of
the Bahamas by Thursday night. That said, latest guidance suggests
that some divergence is possible on Friday across western PR as the
mid level low moves to the north of Hispaniola on Friday, and the
high resolution models do put a good amount of rainfall across NW-PR
on Friday afternoon. There is also an upper level trough that could
enhance the shower activity across the local area on Friday as the
upper low is also expected to be north of Hispaniola and the
associated trough could dig down to just west of PR, again,
supporting some instability over the area.

The overall moisture is forecast to be near normal for the next few
days. The diurnal heating will combine with the local effects and
produce afternoon showers across northwestern PR. The USVI are
expected to observe mainly isolated to scattered brief showers,
except maybe the western sections of St Croix and St Thomas as
showers stream off the islands. At this time, it looks like the
showers on Friday are to affect western PR, but that could be
influenced by the exact location of the troughs in the mid and upper
levels, so there is considerable uncertainty on the forecast for the
amounts of rain elsewhere in the local area for this friday.

.LONG TERM...Saturday through Wednesday...
Models continue to suggest the arrival of low level moisture as
the remnants a cold front move across the local region from
Saturday through Monday. Moisture patches are expected to move
across the local forecast area through at least mid week slightly
increasing the chances of rain.


&&

.AVIATION...VFR conds expected through at least 10/16Z at the local
terminals. VCSH will continue at TJSJ, TISX, and TIST as ISOLD to
SCT SHRA pass by the local flying area. Afternoon SHRA across NW-PR
will cause VCSH at TJMZ and TJBQ at 10/18-22Z. Winds will be up to
10KT through 10/13Z, increasing thereafter up to 15 KT from the SE
with sea breeze variations and occasional gusts.

&&

.MARINE...Climatological marine conditions will continue through
at least Friday. Seas will build again during the weekend as
strong high pressure develops over the central Atlantic. As a
result, seas are forecast to reach 4-6 feet again late in the
weekend and early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 75 90 77 / 20 40 40 10
STT 85 77 84 76 / 20 20 10 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
410 AM AST Thu Apr 11 2019

.SYNOPSIS...An area of clouds and showers located over the virgin
islands early this morning will likely bring additional cloudiness
and showers over Puerto Rico through mid morning.A mid to upper
level trough is forecast to move over the northeast Caribbean
region during the weekend, increasing the instability and moisture
transport. Therefore, higher rainfall accumulations are possible
with the afternoon showers.


&&

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

Satellite imagery shows an area of cloudiness across the eastern
Caribbean which is moving west and into the local islands. This is
due to a positively tilted upper trough to the ENE for the Leeward
islands and a mid level low just east of the Leewards. There is
also a mid and upper level trough across the western Caribbean,
essentially keeping the local islands under a narrow ridge in the
mid and upper levels today. That said, the cloudiness and also
scattered shower activity will move over the local islands today
because at the surface we have a southeasterly wind flow, due to a
high pressure across the eastern Atlantic and a weak surface low
across the western Atlantic. This particular setup will bring
variably cloudy skies and scattered shower activity to the local
islands today. The south and eastern sections of PR could continue to
expect these pesky showers through much of the day with isolated
showers elsewhere and variably cloudy skies. Northwestern PR is also
expected to observe some rain due to afternoon convection but it may
be limited if the cloud cover is too thick, however, at this time it
looks like there may be some cloudiness but not enough to completely
inhibit convection, for that reason, numerous showers are forecast
for the NW sections of PR.

The mid and upper level trough across the western Caribbean is
expected to move into the western Atlantic near the Bahamas with a
Low developing by Friday. At this time it looks like those troughs
will help in the persistence or time duration of the moderate
showers expected across NW-PR on Friday but not necessarily cause
heavier rainfall, so for Friday we are still expecting a somewhat
similar pattern to today with scattered showers across the local
area, affecting south and east PR and the USVI, with afternoon
showers developing across NW-PR once again. Saturday looks more
typical as the local winds will return to an easterly direction,
with the afternoon convection causing shower development across
western PR and brief isolated to scattered showers expected
elsewhere.

.LONG TERM...Sunday through Thursday...
High pressure located over the central Atlantic will continue to
dominate the local weather for most of next week. Patches of low
level moisture will move from time to time slightly increasing the
chances showers across the islands. Enough moisture will be
available for afternoon activity to develop mainly over the
interior and western portion of Puerto Rico through this period.

&&

.AVIATION...VCSH expected across the local terminals through the
forecast period as SCT SHRA moves through the local area. SE winds
will prevail at up to 10 KT through 11/12Z, increasing to 15KT with
occasional gusts and sea breeze variations thereafter through
11/23Z. SHRA could develop across NW-PR after 11/17Z, which could
affect TJBQ, but the SCT SHRA is expected to continue for the rest
of the local terminals.


&&

.MARINE...Seas will continue between 2 and 5 feet and winds up to
15 knots from the SE across most of the regional waters. Similar
marine conditions will continue through at least Saturday morning.
Increasing winds will generate moderate choppy conditions across
all local waters through next week.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 77 89 75 / 30 20 30 40
STT 84 76 85 75 / 40 20 20 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
448 AM AST Fri Apr 12 2019

.SYNOPSIS...Surface high pressure across the eastern Atlantic will
cause east to southeast wind flow today, but another surface high
pressure will enter the western Atlantic today, which will cause
easterly winds this weekend. There is a mid level and upper level
ridge over the local area and a mid to upper level trough to the
northwest, which will move east this weekend. However, the shower
activity expected this afternoon and this weekend will be mainly
locally induced.

&&

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

Variably cloudy skies and frequent passing showers prevailed across
the local islands overnight and early this morning. Rainfall totals
associated with these showers, however, were minimal. Winds were
from the east southeast at 15 mph or less.

Ridge aloft is expected to erode during the upcoming weekend as an
upper level trough over the Bahamas shift eastward. This feature is
expected to reach the eastern Caribbean by Saturday afternoon, with
its axis relocating east of the forecast area by Sunday night. At
lower levels, east southeast winds are expected to prevail today but
becoming more easterly by Saturday as a broad surface high pressure
establishes across the central Atlantic. The aforementioned east
southeast wind flow will maintain low level moisture near the normal
range today, however, as winds become more easterly, a slightly
decrease is expected.

This evolving pattern will not support organized convection but is
not strong enough to suppress the shallow development. Therefore,
continue to expect a seasonal weather pattern with passing showers
across eastern areas in the morning, followed by showers developing
across the western areas of the island in the afternoon. Under the
prevailing east southeast wind flow, afternoon showers will be
focused in the vicinity of Aguadilla today. During the upcoming
weekend, afternoon showers will be focused in the vicinity of
Mayaguez as surface winds become more easterly.

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

Easterly winds are expected to prevail across the local area next
week due to surface high pressures across the Atlantic. In the
upper levels, there is an upper trough to the east of the local
islands on Monday that will remain east of the local islands,
keeping us under the ridge. This trough should flatten by midweek
and zonal flow is expected in the upper levels thereafter. Fairly
uneventful weather pattern expected in the long term as the
available moisture will also remain near normal with the
occasional patch of moisture passing through. Given the expected
pattern, the shower activity over Puerto Rico should be mainly
locally induces across the western sections in the afternoon, with
the USVI and eastern PR observing isolated to scattered showers.


&&

.AVIATION...VFR conds are expected to prevail at all TAF sites
through the forecast period with VCSH possible at JMZ/JBQ between
12/16z and 12/22z. East southeast winds 15 to 20 knots to
continue.

&&

.MARINE...Seas up to 5 feet are expected and winds up to 20 knots.
Small craft operators are urged to exercise caution across the
nearshore Atlantic and Caribbean waters of PR due to winds.
Moderate risk of rip currents expected across many of the local
beaches in PR and Saint Croix. Seas will increase gradually up to
6 feet this weekend and the moderate risk of rip currents will
expend to most of the local beaches.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 75 86 75 / 20 40 40 20
STT 85 76 87 75 / 20 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Sat Apr 13 2019

.SYNOPSIS...Ridge aloft and moderate to fresh easterly winds will
continue to promote a seasonal weather pattern across the local
islands through next week. Therefore, continue to expect a few
passing showers across eastern areas of Puerto Rico as well as in
and around the USVI during the morning hours, followed by showers
developing over west Puerto Rico in the afternoon.

&&

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

Ridge aloft will continue to maintain the atmosphere above 700 mb
very dry with relative humidity values less than 10%. This will
serve to suppress the development of deep and organized convection.
Meanwhile, at the surface, a strong high pressure situated north of
the area will continue to produce a tight pressure gradient through
early next week. This will serve to produce moderate easterly winds
across the area. This easterly wind flow will also transport patches
of low-level moisture, resulting in areas of showers. Under this
general pattern, expect some overnight and early morning passing
showers across portions of eastern PR, the USVI, and surrounding
waters followed by the development of locally and diurnally induced
showers across western PR during the afternoon hours. At this time,
only light to moderate rainfall accumulations are expected given
that conditions at the mid to upper-levels will be unfavorable for
any significant rainfall activity from materializing.

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

A mid to upper level ridge will hold across the local isles through
the forecast cycle. At lower levels, migratory surface highs north
of the area will continue to yield moderate to fresh easterly winds.
Although ridge aloft will promote dry and stable conditions much
of the upcoming work week with precipitable water well below 1.50
inches -- which is the normal value -- patches of low level moisture
embedded in the trades may reach the forecast area at times. Therefore,
still expect a seasonal weather pattern with a few passing showers
across eastern areas of Puerto Rico as well as in and around he
USVI during the morning hours, followed by showers developing
across west Puerto Rico in the afternoon.

&&

.AVIATION...Mainly VFR conditions expected to prevail across the
area throughout the forecast period. SHRA expected across western
PR between 13/17-23z, affecting TJMZ and TJBQ. Brief MVFR
conditions cannot be ruled out. Winds will be from E at around 10
knots through 13/12z, increasing to 15 to 20 knots with gusts
between 25-30 kts and sea breeze variations after 13/14z.

&&

.MARINE...Hazardous marine conditions are expected to prevail
across the Caribbean waters due to seas near 7 feet and easterly
winds around 20 knots. Therefore SCA will be in effect for AMZ732
and AMZ741 later today. Elsewhere, small boat operators should
exercise caution due to seas 4 to 6 feet and winds 15 to 20 knots.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 86 75 / 30 30 20 30
STT 86 76 85 76 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Sun Apr 14 2019

.SYNOPSIS...A seasonal weather pattern will continue to prevail
across the local islands under ridge aloft and moderate to fresh
easterly winds. Ridge aloft may erode by the end of the forecast
cycle. Meanwhile, continue to expect a few passing showers across
eastern areas of Puerto Rico as well as in and around the USVI
during the morning hours, followed by showers developing over west
Puerto Rico in the afternoon.

&&

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

Not much change in the overall pattern is expected throughout the
short-term period. Ridge aloft will continue to maintain stable
conditions aloft, suppressing the development of deep and organized
convection. Therefore, significant rainfall activity is not
expected. A broad surface high pressure over the Atlantic will
continue to promote a moderate easterly wind flow, resulting in
breezy conditions through at least the early part of the work week.

Latest infrared satellite imagery indicates a small area of low-
level cloudiness associated with a surge in the low-level moisture
moving across the area currently with a very dry air mass
immediately behind it with precipitable water values as low as 0.8
inches. This low-level moisture surge will move across eastern PR
during the morning hours, resulting in some passing showers. Then
this moisture will combine with daytime heating and local effects
to result in the development of scattered showers across western
PR during the afternoon hours. The rest of PR and the USVI is
expected to observe mostly sunny skies during the afternoon hours
as the very dry air mass moves overhead.

Another low-level moisture surge is expected on Monday. This will
promote an increase scattered shower activity across the area. As
the surface high pressure moves farther eastward into the Atlantic,
the low-level flow is expected to shift to the east southeast.
Therefore, showers are expected across eastern and southeastern PR
and portions of the USVI during the morning hours extending into the
northwestern quadrant of PR during the afternoon hours.

Lesser shower activity is expected on Tuesday as the low-level
moisture decreases. However, a few showers are still possible mainly
across eastern portions of PR during the morning hours followed by
some showers across western PR during the afternoon hours due to
daytime heating and local effects.

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

A mid to upper level ridge is expected to prevail across the
forecast area through at least the end of the work week. This
feature is expected to erode the upcoming weekend as a broad
trough develops across the central Atlantic and into the eastern
Caribbean. At lower levels, a surface high pressure north of the
area will yield easterly winds much of the forecast cycle.
Although much of the upcoming week a dry air mass is expected to
dominate the eastern Caribbean, the easterly wind flow will
continue to bring patches of low level moisture at times.

The aforementioned set-up will continue to promote a seasonal
weather pattern across the local isles with a few passing showers
across eastern areas of Puerto Rico as well as in and around the
USVI during the morning hours, followed by showers developing
across west Puerto Rico in the afternoon. If the ridge aloft
erodes by the end of the forecast cycle, intensity and areal
coverage of afternoon showers may increase.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across the
local throughout the forecast period. A few passing SHRA may affect
the USVI terminals and TJSJ through 14/14z. SHRA are then expected
across western PR between 14/16z-22z, possibly affecting TJMZ and
TJBQ. Brief MVFR conditions cannot be ruled out. Winds will be from
the E at around 10 kts through 14/12z, increasing to 15 to 20 knots
with higher gusts and sea breeze variations after 14/14z.

&&

.MARINE...A broad surface high pressure across the central Atlantic
will promote moderate to fresh easterly winds through at least
midweek. This will cause wind driven seas up to 7 feet across the
Caribbean waters and Mona Passage, where Small Craft Advisories
continue in effect through this evening. Elsewhere, small craft
operators are urged to exercise caution due to seas up to 6 feet
and east winds up to 20 knots. Choppy marine conditions are
expected much of the upcoming work week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 87 75 / 30 30 30 20
STT 87 77 87 77 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
425 AM AST Mon Apr 15 2019

.SYNOPSIS...Ridge aloft and moderate easterly winds will continue
to promote a seasonal weather pattern across the local islands
during the work week. Therefore, continue to expect a few passing
showers across eastern areas of Puerto Rico as well as in and
around the USVI during the morning hours, followed by showers
developing over west Puerto Rico in the afternoon. Ridge aloft
will erode the upcoming weekend into next week, which may result
in a better chance for shower activity next week.

&&

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

A fair weather pattern is expected to prevail across the region
throughout the short-term period. Ridge aloft will continue to
maintain the mid to upper-levels extremely dry with relative
humidity values less 10%, producing a strong trade wind cap. As a
result, the rainfall activity is expected to be quite limited across
the forecast area as a result of the unfavorable conditions aloft.
The shower activity that occurs across the area will all be
dependent on the patches of low-level moisture embedded within the
easterly wind flow that move across. Therefore, under this general
weather pattern, continue to expect isolated to scattered brief
showers across eastern portions of PR and the USVI during the
overnight and morning hours followed by some locally and diurnally
induced showers across the western half of Puerto Rico during the
afternoon hours. Only light to locally moderate rainfall
accumulations are expected.

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

Long term forecast still on track. Ridge aloft will hold through
the end of the work week, weakening the upcoming weekend into next
week as a deep trough develops across the central Atlantic into
the eastern Caribbean. Al lower levels, a broad surface high will
continue to promote moderate easterly winds through Sunday,
becoming east northeast early next week as an induced surface
trough develops north northeast of the area.

Although much of the forecast cycle dry conditions are expected to
dominate the eastern Caribbean; the easterly wind flow will continue
to bring patches of low level moisture at times. Therefore,
continue to expect a few passing showers across eastern areas of
Puerto Rico as well as in and around the USVI during the morning
hours, followed by showers developing across west Puerto Rico in
the afternoon. Seasonable temperatures to continue. As the ridge
aloft erodes, a better chance for shower activity is possible
next week.


&&

.AVIATION...Mainly VFR conditions expected across all local
terminals throughout the period. Low-level cloud fragments
may result in BKN ceilings and VCSH at times across TNCM/TKPK
through 15/18z. SHRA expected across western PR between 15/17z-
23z, possibly affecting TJMZ and TJBQ. Brief MVFR conditions
cannot be ruled out. Winds will be out of the E below 10 knots
through 15/12z, increasing to 12 to 18 kts with higher gusts
and sea breeze variations after 15/14z.

&&

.MARINE...Moderate to fresh easterly winds will result in choppy
seas of up to 6 feet. Therefore, small craft operators should
exercise caution. There is a moderate risk of rip currents across
most of the local beaches, except across the west coast of Puerto
Rico, where the rip current risk is low.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 76 88 76 / 20 30 20 30
STT 86 77 86 77 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
410 AM AST Tue Apr 16 2019

.SYNOPSIS...Ridge aloft will continue to produce a fair weather
pattern across the local region through the rest of the work week
and into the upcoming weekend. Occasional patches of low-level
moisture, however, will move across the area. This will result in
some passing showers across eastern areas during the overnight
and morning hours followed by afternoon showers across western PR.

&&

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

Mostly clear to partly cloudy skies prevailed across the local isles
overnight and early this morning. Passing showers were observed
across the local waters as well as over eastern Puerto Rico.
Rainfall accumulations, however, were minimal. Overnight low
temperatures ranged in the low to mid 70s across lower elevations
and in the 60s across higher elevations. Winds were generally light
and variable.

TUTT to the east and ridge to the west will continue to prevail. As
the TUTT shifts northeast, the ridge aloft will relocate across the
central Caribbean by the end of the forecast period. At lower
levels, migratory surface highs north of the forecast area will
continue to yield easterly winds across the eastern Caribbean.
Although model guidance continues to suggest precipitable water
below the normal range Tue-Thu; easterly winds will continue to
bring patches of clouds and showers - which are enhanced by the TUTT
to the east - at times.

Therefore, continue to expect a few passing showers across eastern
areas of Puerto Rico as well as in and around the USVI during the
morning hours, followed by some showers developing over western
Puerto Rico in the afternoon. A slight increase in afternoon
shower activity could be expected by the end of the forecast
period as low level moisture increases with some erosion in the
inversion cap. However, only light to locally moderate rainfall
accumulations are still expected.

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

Mid to upper-level ridge will hold across the area through Sunday.
This will continue to promote a fair weather pattern across the
local area. Patches of low-level moisture, however, will continue
to move across the area from time to time. This will result in
some brief showers across eastern portions of PR and the USVI
during the overnight and morning hours followed by showers
developing across western PR during the afternoon hours due to
daytime heating and local effects. During the same time period, a
surface high pressure will establish itself across the north-
central Atlantic and will tighten the local pressure gradient,
resulting in breezy conditions.

Model guidance is currently indicating that the ridge aloft will
erode by Monday as a mid to upper-level trough amplifies across
the western and central Atlantic basin. This change in the overall
weather pattern would result in better moisture pooling across
the area and therefore, a better potential for more enhanced
shower activity.

&&

.AVIATION...VFR conds are expected to prevail at all TAF sites
through the forecast period with VCSH possible at JMZ/JBQ between
16/16z and 16/22z. Easterly winds 15 to 20 knots to continue.

&&

.MARINE...Moderate to fresh easterly winds will continue today
across the area. This will result in choppy seas of up to 6 feet,
mainly across portions of the Atlantic waters and Anegada Passage.
Therefore, small craft operators should exercise caution. Across
the rest of the local waters, seas of up to 5 feet are expected.
For beachgoers, there continues to be a moderate risk of rip
currents for the beaches located along the coastlines of northern,
southeast, and southwest PR, Vieques, Culebra, Saint Croix and
northwest Saint Thomas.

Lower seas are forecast for Wednesday and Thursday as the local
winds diminish. Another wind surge by the end of the work week
into the upcoming weekend will generate choppy seas and possibly
a high risk of rip currents for some of the local beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 86 75 / 20 20 20 40
STT 85 75 84 75 / 20 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
454 AM AST Wed Apr 17 2019

.SYNOPSIS...Mid to upper-level ridge is expected to hold through
the upcoming weekend, resulting in the continuation of a fair
weather pattern. The ridge aloft will erode completely by early
next week as a mid to upper-level trough amplifies across the
western and central Atlantic.

&&

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

As high pressure in the eastern Atlantic recedes to the east
northeast today, another high will move off the coast of South
Carolina and be joined by another high over New England on Thursday.
By Friday, this will create a moderately strong high in the north
central Atlantic with ridging extending into the Central Caribbean.
Low pressure will cut off about 1900 miles northeast of San Juan on
Thursday, and by Friday its associated cold front driven by the
stronger high will approach within 300 miles of the north coasts of
Puerto Rico and the northern U.S. Virgin Islands. Patchy moisture
will continue in these easterly trade winds which will increase
slightly each day during the period and beyond. This moisture will
maintain rapidly passing mostly light showers during the night and
early morning periods--mainly in the northern U.S. Virgin Islands
and eastern Puerto Rico, followed by modest shower development over
western Puerto Rico during the afternoons. The best moisture will be
tonight and late Thursday afternoon, however, so shower activity
fades somewhat on Friday.

Mid levels (700-400 mb) remain almost completely dry through the
period except for minor intrusions of moisture from convection
during the afternoons.

At upper levels, a weak trough will pass mostly north of the area
today accompanied by a jet from 18/00-06Z that may top 60 knots
overhead from the west northwest. A short wave trough will dig
southeast in the western Atlantic and form a fairly vigorous east-
west trough late on Friday about 700 miles northeast of the area
that will keep cyclonic flow over the eastern Caribbean Thursday and
Friday. Despite jets and cyclonic flow though, there is little
divergence aloft and there are some areas of convergence that will
add to the suppression of convection provided already by the capping
at 600-700 mb.

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

The ridge aloft will hold across the region through Sunday. This
will continue to suppress the potential for any deep and organized
convection. A strong surface high pressure is expected to be
located across the north-central Atlantic and will tighten the
local pressure gradient to produce moderate to fresh easterly
trade winds across the region. These trade winds will also
transport patches of low-level moisture across the region from
time to time. Therefore, some brief showers can be expected across
eastern portions of PR and the USVI during the overnight and
morning hours followed by locally and diurnally induced showers
developing across the western half of PR during the afternoon
hours.

The mid to upper-level ridge is expected to erode completely by
Monday as a mid to upper-level trough amplifies across the
western and central Atlantic. Meanwhile, at lower-levels, a low at
the surface and at 700 mb are expected to develop and be situated
northeast of the area. These lows will serve to weaken and shift
the low-level winds to the northeast and also advect low-level
moisture into the region. Therefore, the combination of sufficient
of low-level moisture and more favorable upper-level forcing may
result in more enhanced shower activity with the afternoon
convection during the first half of next week.


&&

.AVIATION...Iso-sct SHRA cont across TIST, ern PR and surrounding
waters thru 17/15Z then SHRA to cause mtn obscurations and MVFR
conds WSW and interior PR till 17/22Z. Sfc winds E incrg to 10-20 kt
aft 17/14Z with gusts to 26kt along N and S coasts of PR. Max winds
WNW 25-35 kt btwn FL320-480 incrg to 50-60 kt btwn FL350-470 by
18/06Z.

&&

.MARINE...Seas between 3 and 5 feet with easterly winds up to 15
knots will prevail across the regional waters for today. A few
areas along the nearshore Atlantic waters just north of Puerto
Rico may see winds to near 20 knots due to local effects.
Therefore, small craft operators should exercise caution across
these waters later this morning into this afternoon. For
beachgoers, there is a moderate risk of rip currents for the
beaches located along the coastlines of northern, southeast and
southwest Puerto Rico, Vieques, Culebra, Saint Croix, and
northwest Saint Thomas.

Winds are expected to increase once again by late Thursday. This
will promote choppy seas and elevate the rip current risk, which
will last into the upcoming weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 86 75 / 40 60 40 30
STT 85 77 85 77 / 40 50 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
454 AM AST Thu Apr 18 2019

.SYNOPSIS...A fair weather pattern is expected to continue into
the upcoming weekend as a ridge aloft holds overhead. Strong
surface high pressure is expected to build across the north-
central Atlantic and tighten the local pressure gradient,
resulting in moderate to fresh easterly trade winds across the
region through Sunday. Ridge aloft is expected to erode completely
by early next week as a mid to upper-level trough amplifies
across the western and central Atlantic.

&&

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

High pressure is building in the western Atlantic north of Puerto
Rico and will move east southeast during the period. It is forecast
to become a 1036 mb high by Saturday (20/18Z). This high will
gradually increase the easterly trade wind flow over the area
through the period. Low pressure will cut off from a trough in
the mid Atlantic today near 40 degrees north 39 degrees west and
migrate southward during the period. The low will adopt a front
associated with the main low and under pressure from the high in
the north its tail will approach Puerto Rico and the U.S. Virgin
Islands, such that by late Saturday it will be about 350 miles
north northeast of San Juan. Patchy moisture will continue to
yield scattered light showers across the area in the usual diurnal
pattern of night and early morning showers in the eastern portion
of Puerto Rico and mostly around the U.S. Virgin Islands over the
local waters, followed by moderate afternoon showers in western
and interior Puerto Rico.

At mid levels, high pressure between the Bahama Islands and eastern
Cuba, will drift to Hispaniola by Friday night and join with a ridge
to the north north east of Hispaniola. On Friday a low will spawn on
the eastern side of the ridge and drop south to east of the Leeward
Islands by Saturday as a reflection of the upper level low mentioned
below. The combination of the ridge and the developing low will
maintain light northerly flow over the local forecast area at mid
levels, but also maintain very low mid level relative humidity.

At upper levels, northwesterly flow will continue on the back side
of the upper level trough now near 55 west northeast of the local
area. Low pressure cuts off in the east central Atlantic on Friday
and another low develops on the southwest side of this low on
Saturday about 600 miles northeast of Saint John. These will both
begin to affect the area in the long term period.

Convection is capped just above 700 mb for the entire period, but
not as strongly as in previous days. This will allow convection to
grow a few thousand feet more than in the last few days, but the dry
mid levels and lack of forcing at upper levels will generally
suppress any shower activity beyond the shallow passing showers of
late that are moved by quickly by the increasing trade wind flow.


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

Current indications are that the remnants of the frontal
boundary, associated with the surface and 700 mb lows that will be
located northeast of the region, will move over the area on
Monday. This feature would increase the low-level moisture and
therefore, the shower activity. Then, as the mid to upper-level
trough amplifies across the western and central Atlantic, a strong
jet between 80 to 100 knots at 250 mb is expected to develop just
north of the area and remain near the area through the end of the
week. Meanwhile, as the surface and 700 mb low meander northeast
of the region throughout the period, the low-level flow will be
from the northeast. These lows will also serve to advect patches
of low-level moisture into the region from time to time from the
northeast. Even though the upper-level forcing may turn more
favorable as a result of the strong jet present aloft, the main
limiting factor for any significant rainfall activity will
continue to be the very dry air that will still be present in the
mid to upper-levels throughout the period. Nevertheless,
sufficient low-level moisture will still be available to generate
isolated to scattered showers across the northern coast of PR and
the northern USVI during the overnight and morning hours followed
by showers across interior and southern portions of PR during the
afternoon hours due to daytime heating and local effects.

&&

.AVIATION...Iso-sct SHRA cont across the waters surrounding the
north and south coasts of PR with few arriving over land. Sfc winds
are E and will incr to 10-22 kt aft 17/14Z with gusts to 27kt along
the N and S coasts of PR. Aft 18/17Z SHRA are to dvlp downstream
from TISX, El Yunque and over wrn PR with lcl MVFR conds nr TJMZ and
mtn obscurations. Tops mostly blo FL150. Conds imprvg aft 18/22Z.
Max winds WNW 50-60 kt btwn FL360-480.

&&

.MARINE...Seas between 3 and 5 feet will continue to prevail
across the regional waters through this afternoon. Winds will be
out of the east up to 15 knots across most areas. However, across
the nearshore Atlantic and Caribbean waters, winds up to 20 knots
are possible due to local effects. Therefore, small craft
operators should exercise caution across these waters. Seas are
expected to increase to up to 6 feet by tonight as the winds will
increase and will remain choppy into the upcoming weekend. In
addition, a small northerly swell will arrive by tonight and
affect mainly the Atlantic waters.

For beachgoers, there is a moderate risk of rip currents for the
beaches located across the coastline of northern, southeast, and
southwest PR as well as across the north and east facing beaches
of Vieques, Culebra, and Saint Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 87 75 / 30 50 40 40
STT 86 75 87 76 / 20 30 40 40