Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
417 PM AST Tue Jan 2 2018

.SYNOPSIS...A stable and relative dry airmass will continue to
prevail across the region through at least late Wednesday, when a
polar trough is forecast to amplify from the west over the
region. Low level winds will shift from east to southeast in
response to the aformentioned polar trough.


&&

.SHORT TERM...Tonight through Thursday...The dry air mass
will continue to prevail over the local region through at least
late Wednesday, limiting rains across the local forecast area.
On Wednesday night, model guidance suggest a strong surface low
pressure moving along the eastern U.S. inducing a southerly wind
flow across the islands, which is forecast to pool tropical
moisture from the south. Southerly winds will also generate a
slight increase on max temperatures mainly along the northern half
of Puerto Rico.


.LONG TERM...Friday through Wednesday...Computer models indicated
a frontal boundary and associated frontal trough will remain
across the southeastern Bahamas and northern Hispaniola Friday and
Saturday. However the proximity of these systems will induce a
moist southeast wind flow across the region. As a result, periods
of showers will be affecting the local region both days. For
Sunday through Wednesday next week, upper level ridge is forecast
to build north of the area. This will result in relatively fair
weather conditions across the northeast Caribbean throughout this
period.


&&

.AVIATION...VFR conditions will continue to prevail across all
terminal through at least 03/06Z. Winds will turn to the east to
southeast ahead of an approaching cold front with VCSH/SHRA
possible on Wednesday.


&&

.MARINE...A surface high pressure across the eastern Atlantic will create an
moderate easterly wind flow through Wednesday maintaining seas between
3 to 5 feet and winds up to 15 kts are expected for most of local
waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 86 75 86 / 20 30 30 20
STT 74 84 74 83 / 20 30 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Wed Jan 3 2018

.SYNOPSIS...A stable and relative dry airmass will continue to
prevail across the region through at least late tonight, when a
polar trough is forecast to amplify from the west over the region.
Low level winds will shift from east to southeast in response to
the aformentioned polar trough.

&&

.SHORT TERM...Today through Friday...Broad polar trough will induce a
surface low over the western Atlantic and as it moves north along
the eastern U.S. coast it will sustain a frontal boundary that is
expected to stall over Hispaniola through the short term period.
East to southeast winds are forecast to prevail through at least
Friday and high temperatures should range in the mid to high 80s
across the coastal areas of the islands. Moisture will increase
gradually during the next couple of days across the region with the
best chance for showers expected across the west/northwestern
portions of PR during the afternoon hours and an increase on
scattered showers across the USVI/Eastern portions of PR during
Thursday and Friday morning.

.LONG TERM...Saturday through Thursday...As frontal boundary stall
over Hispaniola, east to southeast wind flow is forecast to
prevail through the weekend. As a result, passing showers embedded
in the wind flow are expected to affect the local islands from
time to time. Upper level ridge is forecast to build across the
northeast Caribbean by early next week. Therefore, relatively dry
weather conditions are expected throughout the forecast period.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across
all terminals through the forecast period. However, between 03/16z-
22z SHRA is expected to develop across portions of NW PR impacting
mainly the vicinity of TJBQ/TJMZ. Sfc winds will be E-ESE at 5-10
kt, sea breeze variations expected across the west/northern
terminals of PR after 14z.

&&

.MARINE...Tranquil marine conditions with seas at 2 to 4 feet and winds
below 15 knots. A northerly swell is forecast to affect the outer
local Atlantic Offshore Waters late tonight. Therefore, a small
craft advisory will be in effect for those waters through Thursday
afternoon.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 73 86 75 / 20 30 30 30
STT 84 74 84 75 / 20 30 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
359 PM AST Wed Jan 3 2018

.SYNOPSIS...A stable and relative dry airmass will continue to
prevail across the region through at least late tonight, when a
polar trough is forecast to amplify from the west over the region.
Low level winds will shift from east to southeast in response to
the aformentioned polar trough.

&&

.SHORT TERM...Shower free conditions continue to dominate the
local forecast area through the afternoon hours. Model guidance
continues to suggest a more wet and unstable environment across
the region as a mid to upper level ridge will continue to weaken
ahead of a deepening polar trough that will remain to the west of
Puerto Rico.

.LONG TERM...As frontal boundary stall over Hispaniola, east to
southeast wind flow is forecast to prevail through the weekend. As
a result, passing showers embedded in the wind flow are expected
to affect the local islands from time to time. Upper level ridge
is forecast to build across the northeast Caribbean by early next
week. Therefore, relatively dry weather conditions are expected
throughout the forecast period.

&&

.AVIATION...Currently VFR conditions are prevailing across all
terminal sites. SHRA are possible by 03/22Z due to low level
moisture returning to the local sites. Sfc winds are currently
easterly at 5 to 15 kt but winds will turn to the SE at 5 to 15
kts by 04/05Z.

&&

.MARINE...Seas 2 to 4 feet winds out of the east to southeast at
15 kts. A moderate northerly swell is forecast to reach our
local waters between late Wednesday night and early Thursday
morning. Therefore, a small craft advisory will be in effect for
those waters through Thursday. A larger swell pulse associated
with a strong low pressure near the eastern coast of U.S. is
forecast to reach our local Atlantic waters on Saturday morning.
Therefore, dangerous marine conditions will prevail through the
incoming weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 86 75 86 / 30 30 30 50
STT 74 84 75 83 / 30 30 30 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
506 AM AST Thu Jan 4 2018

.SYNOPSIS...Frontal boundary is expected to remain to the west of
the area and across the Atlantic ocean. Moisture will increase
during the next few days under a moist southeasterly wind flow.
Upper level ridge will build northeast of the region and promote
fair weather conditions during the next week.


&&

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

The available moisture will change significantly from one day to the
next in the short term, Friday being the day with the highest
moisture and also the best chance for rain over the local area. The
precipitable water values expected for today will be at around 1.3
inches which is near normal, but will increase to 1.9 to 2 inches on
Friday, which is well above normal, then decreasing to about 1.5 to
1.6 inches on Saturday. Through the next few days, the winds will be
mostly from the SE, becoming easterly at times and increasing in
speed on Saturday. The upper levels will be somewhat constant with a
broad polar trough to our northwest and a high pressure very close
to our east and gradually approaching the local area.

This general setup will give us mostly fair weather today with
isolated to scattered but brief showers across the local waters,
USVI, and eastern PR in the morning and overnight hours and some
showers developing in PR in areas of sea breeze convergence. Friday,
given that it has much more moisture, the chances of rain are higher
and there could be some areas in the interior of PR and near the San
Juan metro that could observe good rainfall, the rest of the local
islands may see slightly more shower activity and cloudiness than
the past few days. Saturday looks similar to today as moisture will
decrease but still a bit higher, so scattered brief showers for the
general area.

.LONG TERM...Sunday through Friday...Frontal boundary is expected
to remain to the north of the region. Mid level ridge to the
northeast of the region will prevail through the long term period,
resulting in drier air and more stable conditions. However, low
level moisture will continue across the region resulting mainly in
a few trade wind showers from time to time and short lived
diurnally induced showers over the islands. East to southeast
moderate to fresh trades will prevail through the first part of
next week, decreasing on Wednesday and Thursday.


&&

.AVIATION...VFR conditions are expected through the forecast
period across the local terminals. Isolated to locally scattered
showers are expected across the local flying area which could
cause VCSH at the USVI terminals and possibly at TJBQ in the
afternoon hours. The local winds over the general area will be
from the SE at about 10KT but there will be sea breeze variations
which will be evident across the TJSJ and TJBQ terminals. Winds
will decrease slightly and become more easterly after 04/22Z.


&&

.MARINE...A long period northerly swell will create seas between
4-6 feet across the Atlantic waters and Passages today. This will
also result in a moderate to high risk of rip currents along the
Atlantic beaches of the islands. Southeasterly winds will prevail
between 10-15 knots. Another long period northerly swell is
expected to affect the local waters during the weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 84 74 / 30 30 50 30
STT 84 76 83 74 / 20 30 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
559 AM AST Fri Jan 5 2018

.SYNOPSIS...The frontal boundary will remain to the west of the
area and across the Atlantic ocean for the next few days.
Moisture will increase during the next few days under a moist
southeasterly wind flow. Upper level ridge will build northeast of
the region and promote fair weather conditions during the next
week.

&&

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

The available moisture will increase today, particularly for the
afternoon hours and linger into Saturday. The precipitable water
will increase to around 1.6 inches, which is above average for the
time of year. The satellite imagery already shows showers
approaching the local islands and some of the lighter showers are
starting to be detected by the Terminal Doppler Radar. Isolated to
scattered brief showers will gradually begin to move through the
local islands today. More persistent, perhaps heavier showers are
expected to affect the western and northwestern sections of Puerto
Rico this afternoon. Similar pattern is expected for Saturday as the
moisture lingers. Then a drying trend is expected on Sunday mid
morning and afternoon as moisture decreases.

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

Frontal boundary is expected to remain to the north of the
region. Mid level ridge to the northeast of the region will
prevail through the long term period, resulting in drier air and
more stable conditions. However, low level moisture will continue
across the region resulting mainly in a few trade wind showers
from time to time and short lived diurnally induced showers over
the islands. East to southeast moderate to fresh trades will
prevail through the first part of next week, decreasing on
Wednesday and Thursday.


&&

.AVIATION...VFR conditions are expected for most of the local
terminals through the forecast period. ISOLD/SCT SHRA expected
across the eastern terminals, causing VCSH and will continue to
spread west to other terminals through the day. TJMZ and TJBQ may
observe brief MVFR conds as SHRA develop over western PR after
05/16Z. The local winds over the general area will be from the East
at 10 KT through 05/14Z,shift to the east southeast with sea breeze
variations thereafter.


&&

.MARINE...Large northerly swell will affect the local waters
through the weekend. Currently, models are underestimating the
swell between 2-6 feet across the western Atlantic, where buoys
are indicating seas between 12-18 feet. Hazardous marine
conditions will prevail across the local waters through at least
late Sunday.

A high rip current risk was issued through the weekend for all the
local islands. High surf and beach erosion are likely on Saturday
across the Atlantic coastline of Puerto Rico. Minor coastal
flooding is possible, but will continue to monitor buoys to see if
conditions warrant a coastal flood watch/advisory for Saturday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 75 / 50 20 30 30
STT 84 74 85 75 / 50 50 50 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
315 PM AST Fri Jan 5 2018

.SHORT TERM...An area of low level moisture continue to move
across the local forecast area today increasing the cloud and
shower coverage through the local islands. Most of these showers
were moderate and of short duration. Satellite images are showing
another area of low level moisture over the Anegada Passage that
is forecast to move west and affect the local island once again
tonight and Saturday morning. This weather pattern of areas of low
level patches moving across the local islands through at least
Sunday morning. A drier and more stable airmass will move over the
region on Sunday.

.LONG TERM...Monday through Friday...
Frontal boundary is expected to remain to the north of the region.
Mid level ridge to the northeast of the region will prevail through
the long term period, resulting in drier air and more stable conditions.
However, low level moisture will continue across the region resulting
mainly in a few trade wind showers from time to time and short lived
diurnally induced showers over the islands. East to southeast moderate
to fresh trades will prevail through the first part of next week,
decreasing on Wednesday and Thursday.

&&

.AVIATION...VFR/MVFR conditions are expected for most of the 05/18Z
TAF period. ISOLD/SCT SHRA are currently moving over TIST, TISX AND
TSJS this activity will continue trough the rest of the 04/18Z
period. Terminals TJPS, TJMZ and TJBQ will see ISOLD/SCT SHRA by
04/22Z this SHRA will last until 06/02Z. The local winds over the
general area will be from the east to southeast at 10 to 15 kts
through 06/00Z TAFS.

&&

.MARINE...The low pressure system in the north Atlantic has generated a
large northerly swell that will affect the local waters through Sunday.
Hazards marine conditions will remain over the local waters through
at least late Sunday.

A high rip current risk was issued through the weekend for all the
local islands. High surf and beach erosion are likely on Saturday
and Sunday across the Atlantic coastline of Puerto Rico.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 86 75 86 / 20 30 30 30
STT 74 85 75 84 / 50 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
421 AM AST Sat Jan 6 2018

.SYNOPSIS...Surface high pressure across the east central Atlantic
will meander in the area for the next few days until another
surface high pressure moves into the western Atlantic early next
week. Broad upper level trough will move to the north in the next
few days then a smaller upper trough will move from the Gulf of
Mexico east until it is just north of the local islands by late
next week, possibly causing some instability over the area. Higher
than normal moisture to remain over the area through Sunday,
drying for Monday and Tuesday.

&&

.SHORT TERM...Today through Monday...
A frontal trough will remain near stationary across the Atlantic
waters to the west northwest of the local area for the next few
days. Small patches of moisture embedded in the easterly trades
will move across the local islands from time to time producing
brief periods of passing showers across the region during the
morning hours. Isolated to scattered showers are also expected to
develop this afternoon across western and interior sections of
Puerto Rico. However, not significant or widespread precipitation
is expected. Latest satellite images are showing another area of
low level moisture over the Leeward islands that is forecast to
move west and affect the local islands once again late this
afternoon and tonight. This area of moisture is expected to remain
across the region through Sunday morning. Model guidance suggests
that a drier and more stable airmass will move over the region
Sunday afternoon, limiting the shower activity through at least
mid week.

.LONG TERM...Tuesday through Saturday...
Upper level trough expected to be in the Gulf of Mexico will
gradually move to the east through the upcoming week which could
enhance the local instability slightly as the axis of the trough
gets closer to the local area but still mainly to our north. The
available moisture will be generally near to slightly above normal
for this period. Therefore at this time we expect a relatively
seasonal pattern but with slightly higher amounts of rain across
eastern due mainly to trade wind showers with higher than normal
moisture and possibly higher instability over Puerto Rico in the
upcoming week as the upper trough approaches. A broad SFC high
pressure is expected to build across the Central Atlantic by late
in the week, and therefore easterly to ESE winds are expected for
the long range forecast period.

&&

.AVIATION...Mostly VFR conditions are expected across most of
the local flying area with only VCSH across the Leewards, USVI and
TJSJ taf sites until at least 06/15z. SHRA are expected to develop
after 06/17z across interior and western PR, affecting mostly TJMZ
and TJBQ taf sites. Latest TJSJ sounding indicated an east to east
southeast low level wind flow all the way from the surface to around
10k feet, becoming easterly and then southerly aloft.


&&

.MARINE...The local marine conditions are very hazardous. There is
a Small Craft Advisory, a high risk of rip currents and a high
surf advisory, all of which are in effect for today and at least
through Sunday. The marine guidance seems to be underestimating
the wave heights and some adjustments were made by the previous
shift. The latest guidance did not change from the previous and
the latest observations are still in agreement with the previous
forecast, for that reason the marine forecast was kept as
inherited. However, if the guidance underestimated by a larger
margin later today, the local marine and surf conditions will be
even more hazardous and in that case the possibility of a coastal
flood advisory will be considered. We held back on issuing the
advisory due to some uncertainty but we will monitor the situation
closely, but needless to say, the conditions are hazardous,
especially for the Atlantic coasts of the local islands as well as
the western and some eastern coasts.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 74 / 50 50 50 10
STT 85 75 84 74 / 40 30 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
545 PM AST Sat Jan 6 2018

.SYNOPSIS...Surface high pressure will continue across the east
central Atlantic. East to southeast trades will prevail through
mid week. Upper level trough will continue to the north/northwest
of the area through early next week. An upper ridge builds aloft
by mid week. Another upper trough is forecast to remain to the
northwest of the area by late next week.

&&

.SHORT TERM...Today through Monday...A perturbation on the trades
will result in a surge in moisture and winds through early Sunday
morning. Periods of passing showers and gusty winds are expected
at times across the U.S. Vrigin Islands and the eastern half of
PR. Drier air is expected behind this feature from Sunday
afternoon through Monday. However, residual low level moisture on
Sunday afternoon will aid in the development of showers across the
NW quadrant of PR and streamers forming off the USVI into eastern
PR. Afternoon showers are expected once again on Monday.

.LONG TERM...Tuesday through Saturday...From previous
discussion...Upper level trough expected to be in the Gulf of
Mexico will gradually move to the east through the upcoming week
which could enhance the local instability slightly as the axis of
the trough gets closer to the local area but still mainly to our
north. The available moisture will be generally near to slightly
above normal for this period. Therefore at this time we expect a
relatively seasonal pattern but with slightly higher amounts of
rain across eastern due mainly to trade wind showers with higher
than normal moisture and possibly higher instability over Puerto
Rico in the upcoming week as the upper trough approaches. A broad
SFC high pressure is expected to build across the Central Atlantic
by late in the week, and therefore easterly to ESE winds are
expected for the long range forecast period.



&&

.AVIATION...Mostly VFR conditions are expected across most of
the local flying area through at least 07/12z. An increase in
cloudiness with showers is expected late tonight through early
Sunday morning. As a result, periods of VCSH/SHRA can be expected
mainly across TISX, TIST and TJSJ. Low level winds will be mainly
from the east southeast at less than 10 kts.


&&

.MARINE...Long period northerly swell will continue to create
rough and hazardous seas across the regional waters through at
least early next week. This swell will generate large breaking
waves along the west coast of Puerto Rico and along the Atlantic
coastline of the islands during the next few days.Please refer to
the latest coastal hazards message (CFWSJU) for detailed
information.

A coastal flood advisory remains in effect through the overnight
hours for the west to northeast coast of Puerto Rico, Culebra and
St. Thomas. Small craft advisories will continue in effect through
at least early next week and they could be extended through the
work week as seas will continue to range between 6-8 feet.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 74 86 / 50 50 10 20
STT 75 84 74 85 / 50 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
515 AM AST Sun Jan 7 2018

.SYNOPSIS...Surface high pressure is expected to remain across
the east central Atlantic then move further east during midweek.
Southeast trade winds will be observed today, becoming easterly on
Monday through the rest of the week. Broad upper level trough
will continue to the northwest of the local area for the next few
days. An upper ridge builds aloft by mid week, but then another
upper trough is forecast to remain to the north to northwest of
the area by late this week.

&&

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

Latest satellite images as well as surface analysis depicted the
remnants of a frontal trough near stationary across the Atlantic
waters just to the west and northwest of the local islands. Across
the local area, an area of low level moisture associated with a
perturbation on the easterly trades will continue to result in
isolated to scattered showers and gusty winds mostly across the
U.S. Virgin Islands, Culebra, Vieques as well as across the
eastern and southeastern sections of Puerto Rico through the rest
of the morning hours. However, not significant or widespread
precipitation is expected. Model guidance suggests that a drier
and more stable airmass will move over the region this afternoon
and tonight, limiting the shower activity through at least mid
week. However, residual low level moisture will aid in the
development of showers across the NW quadrant of PR this
afternoon.

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

Latest guidance still shows an upper level trough in the Gulf of
Mexico that will gradually move to the east through the upcoming
week starting on Monday, which could enhance the local
instability slightly as the axis gets closer to the local area
but still mainly to our north late in the workweek. The available
moisture is still expected to be generally near to slightly above
normal for this period. A seasonal pattern is expected in the long
range but with slightly higher amounts of rain across eastern
Puerto Rico due the higher than normal moisture and possibly
higher instability as the upper trough approaches late in the week.
A strong SFC high pressure is expected to move into the Central
Atlantic late in the workweek, keeping the easterly winds that are
already expected starting this Monday.


&&

.AVIATION...Brief periods of MVFR conditions will continue across
TIST and TJSJ with mostly VFR conditions expected across most of the
local flying area through at least 07/15Z. Areas of MVFR are likely
to develop across NW PR after 07/17Z with vcnty SHRA around
TJMZ/TJBQ till 07/21Z. Latest TJSJ sounding indicated a southeast
wind flow up to 25 knots all the way from the surface to 23k feet,
becoming westerly and stronger aloft.


&&

.MARINE...The hazardous to dangerous marine conditions continue
today. We decided to extend the high surf advisory until 4 PM this
afternoon. The main reason was because the guidance was still
under estimating the wave heights and period. Buoy 41043 north of
the islands has wave heights of 11 feet and 14 second period with
the swell coming from the NNW. This translates to estimated seas
of 8 to 9 feet or so and a period roughly the same at 14 seconds
during the day today across the local Atlantic beaches and
portions of western coast of PR, which could produce breaking wave
heights of 12-15 feet at times. Also, the risk of rip currents
increased today across many areas, partly because winds of 20
knots from the SE will combine with the high wave heights across
the area, so we have a high risk of rip currents today across many
areas and moderate risk elsewhere. Please refer to the local
marine products for more details on timing and areas affected.
Bottom line is that the marine and surf zone conditions are
dangerous and there is a chance of some coastal flooding today as
well.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 86 74 / 50 10 20 20
STT 84 73 85 74 / 40 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST Tue Jan 9 2018

.SYNOPSIS...An upper level ridge will remain as the main weather
feature over the region through the end of the week. An upper
level trough over Florida and Cuba is expected to drift to the
northeast during the next few days. Another upper trough will
continue east of the lesser Antilles over the Tropical Atlantic.
This trough will enhance trade wind showers during the second
part of the week. A weak surface high pressure will continue
across the East Central Atlantic through midweek when it will be
replaced by another broad surface high across the West Central
Atlantic. East winds will prevail for the next several days and
will increase after Wednesday.

&&

.SHORT TERM...Today through Thursday...
An upper level ridge over the Leeward Islands will move little as a
cut-off low lays squarely between 10 and 20 north and 40 and 50 west
until Friday and a second low moves across Florida Wednesday. At
lower levels transient highs move across the Atlantic at mid
latitudes. The latter one will become quite strong by Thursday,
increasing low level easterly winds even though it holds its
distance at around 38 north.

A cold front stretching northeast-southwest across the western
Atlantic will pivot around a point near 27 north 60 west, becoming
east-west by Wednesday. This will allow tropical air at lower levels
to bring patches of moisture and showers across the area with
precipitable water increasing to 1.8 inches by Thursday morning.
However the atmosphere at mid levels will remain almost completely
dry even though the depth of the lower moist layer will deepen to
around 18 kft by Thursday morning. With dry air at mid levels, and
the front too far to the north, convection will be limited to
passing trade wind showers across the U.S. Virgin Islands and
eastern Puerto Rico during the nights and early morning hours much
as we have seen the last few days. But with increased moisture we
should begin to see increasing afternoon shower in the northwest and
interior during the afternoon hours. Temperatures will change
little.

.LONG TERM...Friday through Tuesday...
An upper level ridge will hold over the region Friday through at
least Saturday. This feature will maintain a relatively dry
weather conditions across the region during that period. Latest
model guidance indicates that an upper level trough will move
eastward across Cuba and Bahamas during the upcoming weekend, but
the bulk of the energy associated with this trough is expected to
remain to the west and north of the region. Another upper level
trough will develop northeast of the region Sunday and Monday,
but most of the energy associated with this trough is expected to
remain northeast of the local islands. The available moisture is
still expected to be generally near to slightly above normal for
this period. A strong surface high pressure is expected to move
into the Central Atlantic Friday and during the upcoming weekend,
maintaining an easterly wind flow across the region. Patches of
low level moisture embedded in the easterly trades are expected to
move across the region from time to time producing brief periods
of showers mostly across the U.S. Virgin Islands, Vieques, Culebra
as well as across the eastern sections of Puerto Rico during the
nights and early in the mornings with some shower activity each
afternoon across western sections of Puerto Rico. However, not
widespread or significant precipitation is expected.

&&

.AVIATION...VFR conds are expected to prevail at all TAF sites.
Passing patches of moisture will create the following conds: Some
brief MVFR may occur in ern third of PR bfr 08/14Z with mtn
obscurations. And brief MVFR may occur at TNCM/TKPK btwn 08/07-14Z
due to CIGS. SHRA will dvlp aft 08/17Z in wrn PR with MVFR CIGS but
conds are expected to remain VFR at TJBQ. SHRA return to ern PR aft
08/19Z also with mtn obscurations and to TNCM/TKPK aft 10/21Z with
MVFR psbl. Winds ESE 10-20 kt to FL160. Bcmg SSW and increasing abv
FL220. Max winds W 30-40 kt FL370-490.

&&

.MARINE...Northerly swell will begin to slowly diminish during
the next few days, however, wind driven seas will continue to
result in hazardous seas through the rest of the week across the
regional waters. Therefore, small craft advisories will remain in
effect both Atlantic and Caribbean offshore waters and the Anegada
passage through at least Friday. Easterly winds will prevail
through the rest of the week between 15-20 kts with higher gusts
at times.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 75 84 75 / 30 30 30 40
STT 84 74 84 75 / 30 40 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
509 PM AST Tue Jan 9 2018

.SYNOPSIS...Showers will increase across the area as low level
moisture moves in from the east tonight through Thursday night. an
upper level ridge will remain just east of the area until a trough
moves south to just north of the tropical Atlantic to the east,
but mid level moisture will continue to be quite limited.


&&

.SHORT TERM...Tonight through Friday... Partly cloudy skies
prevailed across Puerto Rico and the U.S. Virgin Islands this
afternoon. Some light passing showers were noted across the
coastal waters. Relatively dry weather conditions will continue to
prevail across the area through late tonight. An area of low
level moisture is forecast to affect the region late tonight
through at least Thursday. As a result, an increase in cloudiness
with showers is expected by late tonight. A drier air mass is
anticipated by Friday.

.LONG TERM...Saturday through Tuesday
On Friday a weak jet crosses Puerto Rico as another patch of
better moisture moves in Saturday morning to bring back the
shower activity. The upper level ridge that had remained across
the Leeward Islands for nearly a week will be pushed across the
area on Friday and hold to the west while a trough drops south out
of the west central Atlantic to just north of the western
tropical Atlantic Saturday. A series of troughs at 700 mb will
bring scattered showers to the area through at least Tuesday with
lower level winds alternating between almost east northeast and
southeast. Because of the limited mid level and the moderate wind
flow of 15 to 25 knots above the surface, rainfall amounts will
be modest and generally under 3 tenths of an inch each day in the
upslope areas of the windward mountains.

&&

.AVIATION...Mostly VFR conditions are expected across most of
the local flying area through at least 10/12z. Some light passing
showers are possible across most terminals. Low level winds will be
mainly from the east at less than 10 kts tonight. Winds between 10
to 15 kts with higher gusts are expected Wednesday morning. An
increase in shower activity is expected tonight. Maximum winds
west 30-40 kts btwn FL390-470.

&&

.MARINE...Seas will relax very gradually, but increase again next
weekend. Small craft advisories are not expected to come down in
much of the Caribbean until early next week.

&&

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

[TexasBreeze]

LAST thing PR needs is Tsunami worries. An advisory has been issued for a 7.8 by Honduras...

[cycloneye]

LAST thing PR needs is Tsunami worries. An advisory has been issued for a 7.8 by Honduras...

Nothing bad happened thankfully.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
501 AM AST Wed Jan 10 2018

.SYNOPSIS...An upper level ridge will remain as the main weather
feature over the region through the upcoming weekend. An upper
level trough over Cuba and Florida is expected to drift northeast
for the next few days. Another upper trough will remain to the east
of the lesser Antilles over the Tropical Atlantic. A surface high
pressure across the central Atlantic will drift eastward through
the end of the work week when it will be replaced by another
broad surface high across the West Central Atlantic. Patches of
moisture embedded in the easterly trades will continue to move
from time to time across the local islands.

&&

.SHORT TERM...Today through Friday...
Although the weather conditions will be dominate by an upper
level ridge, showers embedded in the trades will move across the
local waters, the U.S. Virgin Islands and the eastern portions of
Puerto Rico through the day. This surge of moisture will induce
showers across the interior and western sections of Puerto Rico
during the afternoon hours too. The upper level ridge will
continue in place through the rest of the work week with patches
of low level moisture which are forecast to affect the region from
time to time. Therefore, the local weather will be driven by
trade wind showers during the night and morning hours followed by
some convection across the interior and western sections of PR
during the afternoon hours each day.

.LONG TERM...Saturday through Wednesday...
A mid to upper level ridge will hold over the region until early
during the upcoming weekend. This feature will maintain a
relatively dry mid to upper airmass across the local islands
during that period. Latest model guidance indicates that an upper
level trough will move eastward across Cuba and Bahamas during
the upcoming weekend, but the bulk of the energy associated with
this trough is expected to remain to the west and north of the
region. Another upper level trough will develop northeast of the
region Sunday and Monday, but most of the energy associated with
this trough is expected to remain northeast of the local islands.
The available moisture is still expected to be generally near to
slightly above normal for this period. A strong surface high
pressure is expected to move into the Central Atlantic Friday and
during the upcoming weekend, maintaining an easterly wind flow
across the region. Low level perturbations in the easterly trades
are expected to move across the region from time to time during
the period producing brief periods of showers mostly across the
U.S. Virgin Islands, Vieques, Culebra as well as across the
eastern sections of Puerto Rico during the nights and early in the
mornings with some shower activity expected each afternoon across
western sections of Puerto Rico. However, not widespread or
significant precipitation is expected.

&&

.AVIATION...Passing -SHRA/SHRA are expected across the Leeward
Islands, the USVI and E-PR terminals through at least 10/20z. SCT-
BKN ceilings at FL025-FL080 at times. SHRA/+SHRA are possible btwn
10/18-22z near TJMZ/TJBQ. No TSRA are expected at this time. Light
to calm and variable winds expected til 10/13z, then easterly winds
btwn 10 and 15 knots with higher gusts near showers.

&&

.MARINE...Seas will relax very gradually, but increase again next
weekend. Small craft advisories are not expected to come down in
much of the Caribbean until early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 73 / 60 60 60 30
STT 84 74 84 75 / 40 40 40 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
411 PM AST Wed Jan 10 2018

.SYNOPSIS...Upper level ridge over the eastern Caribbean will
remain in place over the local forecast area at least through
Friday. Upper level trough/low over southeast CONUS/Florida will
slowly drift east as it fills. Surface high centered just off the
coast of southern New England will move East Southeast to the
central Atlantic through Saturday.


&&

.SHORT TERM...Tonight through Saturday...Upper ridge mentioned
above will remain across the northeast Caribbean through this
period limiting somewhat the rainfall activity. However...patches
of moisture from the tropical Atlantic will continue to be
advected westward across the Lesser Antilles and PR/USVI area.
This will be further enhanced Friday through Saturday as the surface
ridge off New England moves quickly east southeast tightening the
pressure gradient across the tropical Atlantic/eastern Caribbean.
This will result in an increase in the low level moist easterly
flow with an increase in low level convergence across the local
islands. Will expect this to result in the tipical nighttime/early
morning showers across the USVI and eastern PR with the focus of
the convection/showers shifting to interior/west PR during the
afternoons.

.LONG TERM...Sunday through Wednesday...No significant changes in
the overall synoptic pattern is expected through this period. The
northeast Caribbean will continue under an upper level ridge and
mostly east to northeast winds at the low levels. The only
foreseeable difference at this time may be slightly less
available moisture and this may result in lower chances for rain.


&&

.AVIATION...Isold to sct -SHRA/SHRA are expected across the
eastern terminals through at least 11/12z. SCT- BKN ceilings at
times. Light to calm and variable winds expected til 11/13z, then
easterly winds btwn 15 and 18 knots with higher gusts near
showers.


&&

.MARINE...Seas will continue to subside slowly, however, seas are
expected to build again by Saturday as the surface pressure
gradient tightens resulting in increasing winds. Small craft
advisories should continue in effect over most of our local waters
through at least the upcoming weekend.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 86 73 84 / 50 50 30 50
STT 73 83 75 84 / 40 30 20 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
449 AM AST Thu Jan 11 2018

.SYNOPSIS...Upper level ridge over the eastern Caribbean and South
America will remain as the main weather feature across the forecast
area through at least the upcoming weekend. Upper level trough/low
over Bahamas will slowly drift northeastward while filling. Surface
high centered over the northwest Atlantic will move eastward while
strengthening across the central Atlantic through the upcoming
weekend.

&&

.SHORT TERM...Today through Saturday...
An upper ridge aloft will remain as the main feature but another
surge of moisture will bring shallow passing showers across the
eastern half section of Puerto Rico, the U.S. Virgin Islands and
the surrounding waters. Shower development is expected across
western PR during the afternoon. Once again, thunderstorm activity
is not likely today. A patch of dry air will arrive later this
afternoon reducing the frequency of showers early Friday morning
into the afternoon.

A surface high pressure across the western Atlantic will aid in
breezy conditions through the weekend. Under this pattern, patches
of moisture will continue to be advected from the east across PR and
the USVI. This will bring above normal tropical moisture which
combined with low level convergence will result in the typical
scattered showers across the U.S. Virgin Islands and the eastern
half portion of PR during the morning and overnight hours. Then,
shower development is expected across west PR during the afternoon
hours, with additional activity across E-PR/USVI.

.LONG TERM...Sunday through Thursday...
No significant changes in the overall synoptic pattern is
expected through this period. The northeast Caribbean will
continue under an upper level ridge and mostly east to northeast
winds at the low levels. The only foreseeable difference at this
time may be slightly less available moisture and this may result
in lower chances for rain.

A mid to upper level ridge will hold over the region through early
next week. This feature will maintain a relatively dry upper level
airmass across the local islands during that period. Latest model
guidance indicates that an upper level trough/low will remain
northeast of the region while filling through the middle of the
upcoming week. A strong surface high pressure is expected to move
across the central Atlantic maintaining a breezy east to east
northeast wind flow across the local islands until at least
Tuesday. The available moisture is still expected to be generally
near to slightly above normal for this period. Low level
perturbations in the trades are expected to move across the
region from time to time during the period producing brief periods
of showers mostly across the U.S. Virgin Islands, Vieques,
Culebra as well as across the eastern sections of Puerto Rico
during the nights and early in the mornings with some shower
activity expected to develop each afternoon across western
sections of Puerto Rico. However, not widespread or significant
precipitation is expected.

&&

.AVIATION...Clouds and passing -SHRA/SHRA will continue to affect
TAF sites from time to time except for TJMZ/TJBQ. Showers are
expected to develop in or near TJMZ/TJBQ btwn 11/18z-22z. Sfc winds
will be mainly from the east at 10 kts or less, increasing around 15
kt aft 11/13z.

&&

.MARINE...Seas will continue to slowly subside today, however,
seas are expected to build again by Saturday as the surface
pressure gradient tightens resulting in increasing winds. Small
craft advisories should continue in effect over most of our local
waters through at least the upcoming weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 73 85 73 / 50 30 50 50
STT 84 75 84 75 / 30 30 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
304 PM AST Thu Jan 11 2018

.SYNOPSIS...A little drying this afternoon and tonight will be
followed by a return of moisture through Saturday. High pressure
aloft will continue to moderate showers but patchy low level
moisture and passing trade wind showers will continue through much
of the upcoming week with a drying trend Monday through Thursday.

&&

.SHORT TERM...Today through Sunday... Variably cloudy skies
prevailed across Puerto Rico and the U.S. Virgin Islands this
afternoon. Some showers were observed across the western half of
Puerto Rico late this morning. By noon, a drier air mass moved
across the local area. A decrease in low level moisture was
evident in satellite images. This weather pattern will continue
through early Friday morning. By Friday morning, another patch of
low level moisture is forecast to approach the local islands. As a
result, an increase in low level moisture is expected. For
Saturday, better moisture is expected to encompass the region.
High pressure will continue to dominate the northern Atlantic into
the weekend. Low pressure will move into the western Atlantic
where it will be detained by the strengthening high Saturday and
Sunday.

.LONG TERM...Monday through Thursday... High pressure will
strengthen as it moves into the northeast Atlantic Ocean, but this
will allow the low and its accompanying frontal system to move
into the western Atlantic to our north. This will bring a relaxed
gradient, weaker winds, and will also diminish the amount of
showers as moisture wanes somewhat Monday through Thursday. We
must still expect, however, the steady flow of cool moist air at
lower levels for brief passing trade wind showers, in eastern
Puerto Rico and the U.S. Virgin Islands during the overnight and
early morning hours, and spreading to the western sections of
Puerto Rico during the afternoons. But amounts and coverage will
diminish.

&&

.AVIATION...VFR conditions will prevail across all TAF sites through
at least 12/12z. Low level winds will continue mainly east at 10 to
15 kts. An increase in cloudiness with VCSH is expected after 12/12z
around TIST, TISX, and TJSJ.

&&

.MARINE...Seas will diminish only slowly through Saturday. Then
conditions will improve considerably so that sunday seas of 7 feet
should be limited to only the outer Atlantic waters and the
Anegada Passage. At this time seas should relax so that all Small
Craft Advisories are down by mid week next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 85 75 84 / 30 40 40 40
STT 75 84 75 84 / 30 40 50 20

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
515 AM AST Fri Jan 12 2018

.SYNOPSIS...
The ridge aloft will continue to erode through the day. A trade
wind inversion is expected to persist through at least Sunday. A
surface high pressure will continue across the Atlantic Ocean.
Therefore, breezy trade winds will push showers and clouds across
the region from time to time.

&&

.SHORT TERM...Today through Sunday...
Upper level ridge will continue to erode today. However, broad
surface high pressure across the Central Atlantic will continue to
push trade wind showers under a breezy easterly wind flow across
portions of the USVI and eastern PR. On Saturday and Sunday, a
TUTT low to the northeast of the region will provide better upper
level dynamics for showers to develop over the mountain ranges of
the islands and over the western interior portions of Puerto Rico.
Daytime temperatures should reach each day the mid to high 80s
across the lower elevations to the low and mid 70s across the
higher elevations. Nighttime temperature will range from the low
60s across the higher elevations to the mid 70s across the lower
elevations. East winds will prevail at 10-20 mph with higher gusts
at times.

.LONG TERM...Monday through Friday...
A mid to upper level ridge is forecast to build over the region.
A surface high pressure will shift into the northeast Atlantic
Ocean allowing a surface low pressure and a frontal boundary to
move into the western Atlantic Ocean. As this happen, the local
pressure gradient is forecast to weaken as well as the local
easterly winds. This will result in a seasonal weather pattern
across the islands, with cool air advection with brief trade wind
showers in eastern Puerto Rico and the U.S. Virgin Islands during
the overnight and early morning hours. Followed by convection
across the western sections of Puerto Rico during the afternoons
with passing showers across E-PR and the USVI.

&&

.AVIATION...Mainly VFR conditions will prevail across all
terminals through the forecast period. However, -SHRA in trade
winds may affect from time to time the USVI/Eastern PR terminals
through the day. Low level winds will continue from the east at
15-25 kts.

&&

.MARINE...
Fresh to strong easterly winds will affect the local waters
through the weekend. In addition, a northerly swell will persist
through the weekend. For that reason, small craft advisories will
continue in effect through the weekend. Marine conditions are
forecast to slowly improve by the upcoming week. However, the
marine conditions across the Atlantic waters will remain
dangerous.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 76 84 75 / 40 40 30 30
STT 84 75 84 74 / 40 50 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
519 AM AST Sat Jan 13 2018

.SYNOPSIS...
Breezy trade winds will continue to push clouds and passing
showers across the islands at times. The trade wind inversion will
continue through at least Sunday. A TUTT low will continue mainly
to the northeast of the Leeward islands through at least early
next week.

&&

.SHORT TERM...Today through Monday...
A band of scattered showers will continue to move from the east
across the area through the early morning hours. The bulk of the
showers should remain over the Atlantic waters. A TUTT low will
continue mainly to the northeast of the Leeward islands through
the short term period. Model guidance suggest that a jet maxima
aloft will move between eastern PR and the USVI this afternoon
providing a better chance for showers to develop over the islands.
At lower levels, broad surface high will continue across the
Atlantic waters through the forecast period. Breezy east to
northeast trades will continue through at least Sunday morning.
Ridge aloft builds from the west and fair weather conditions
return by Sunday and Monday.

.LONG TERM...Tuesday through Saturday...
The mid to upper level ridge will continue over the region through
at least mid-week. The islands will be under a northeasterly wind
flow due to a surface high pressure across the eastern Atlantic
Ocean. This will result in a seasonal weather pattern across the
islands, with cool air advection and brief trade wind showers
across eastern Puerto Rico and the U.S. Virgin Islands during the
overnight and early morning hours. Followed by convection across
the western sections of Puerto Rico during the afternoons with
passing showers across E-PR and the USVI. Model guidance
suggested a surface low pressure and a frontal boundary inducing
moisture pooling and low level convergence across the region
between Thursday and early Saturday.

&&

.AVIATION...Mainly VFR conditions will prevail across all terminals
through the forecast period. However, trade wind showers could move
across the Leeward/USVI/eastern Pr terminals through the forecast
period. Afternoon SHRA over eastern interior/west PR could impact
the flying area of TJSJ/TJMZ. Low level wind will continue east at
15-25 kts.

&&

.MARINE...Hazardous marine conditions will persist through the
weekend as a northeasterly swell and breezy conditions continues
across the islands. Seas are expected between 6 and 8 feet across
the Atlantic Ocean and at 5 to 7 feet across the Caribbean Waters.
Small craft advisories are in effect across most of the local
waters through at least Sunday. Seas are forecast to improve
somewhat by early next week, but the outer Atlantic waters may
see 7 foot seas. Rip current risk will continue high across the
beaches along the Atlantic waters of Puerto Rico, Culebra and St
Croix.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 76 84 75 / 50 30 20 10
STT 85 74 85 74 / 40 30 20 10

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
353 PM AST Sat Jan 13 2018

.SYNOPSIS...Low level moisture from easterly trades has sparked
scattered showers over Puerto Rico and the U.S. Virgin Islands.
Scattered showers will continue through the rest of the day and
should start to diminish by 10 PM. Sunday the low level moisture
will begin to decrease but isolated showers are still possible
with partly cloudy conditions. A ridge of high pressure will
build in from the east and create fair weather conditions for
Puerto Rico and the U.S. Virgin Islands with a possible trade wind
shower mainly during the morning and afternoon hours.

&&

.SHORT TERM...Today through Monday... Partly cloudy skies
prevailed across Puerto Rico and the U.S. Virgin Islands today.
This morning a patch of low level moisture moved through the area
which helped triggered showers this morning and afternoon.
Doppler radar shows scattered showers across most of the northern
coast of Puerto Rico this activity will continue across Puerto
Rico and the U.S. Virgin Islands through the overnight hours. A
TUTT low will remain to the northeast of the Leeward islands until
Monday, then it will begin to dissipate. At the lower levels, a
surface high pressure system will remain over the region over the
next several days with winds out of the east to northeast 15 to 20
mph.

San Juan GFS model shows the highest precipitable water and
relative humidity values today, these values will slowly decrease
tonight through next week. An upper level ridge of high pressure
will build in from the west and hover over the region on Monday
with fair weather conditions to start the work week.

&&

..LONG TERM...Tuesday through Sunday.... Mid to upper level ridge
will remain over the region through Friday. This will cause
seasonal weather with an occasional trade wind showers across
eastern puerto rico and the U.S Virgin Islands typically during
the morning and afternoon hours. A front will move off the east
coast of the U.S. on Wednesday and will continue to progress to
the east which could help pull tropical low-level moisture across
Puerto Rico and the U.S. Virgin Islands late Thursday or early
Friday.

&&

.AVIATION...VFR conds will prevail except around TJMZ/TJBQ and in
the Leeward Islands where MVFR due to CIGS in brief passing SHRA
will occur. SHRA arnd wrn PR to end aft 13/23Z but brief MVFR to
cont in TNCM/TKPK. Mtn obscurations. Sfc winds subsiding aft 13/22Z
to bcm E 10 kt or less. East flow to resume 10 to 15 kt with gusts
to lower 20s with Sea breeze influences aft 14/14Z. Maximum winds NW
30-40 kt FL320-490.

&&

.MARINE...


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 84 75 85 / 30 20 10 20
STT 74 85 74 85 / 30 20 10 20