Caribbean - Central America Weather

[cycloneye]

Happy New Year, Luis
Thanks for the daily updates

Same to you.Thank you.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
139 PM AST Sun Jan 8 2017

.SYNOPSIS...Ridge aloft will continue to weaken as a polar trof
amplifies toward the southeast across the Southwestern Atlantic.
TUTT is forecast to develop northeast of the area by the end of
the week. Cold front will approach the area by Monday with
associated prefrontal trough moving over the islands through mid
week.


&&

.DISCUSSION...Isolated to scattered showers moved inland and
affected the Southeast portions of Puerto Rico through mid
morning. Most of these showers dissipated before noon. isolated to
locally scattered showers started to develop over the Western
Interior sections of Puerto Rico and due to the a more NE
component on the steering winds these showers are moving slowly
toward the southwest portions of Puerto Rico. Most of these
showers will dissipate before sunset. Expect showers affecting the
Eastern portions of Puerto Rico through the overnight hours as
patches of moisture embedded within the trades winds will bring
again isolated to locally scattered showers over this area.

There will be a significant change on this weather pattern.
as moisture is forecast to increase across the area on Monday. A deep
polar trof and associated frontal boundary will moves across the
islands through Tuesday. However, a broad area of low pressure is
forecast to develop under a TUTT to the northeast of the islands
by the end of the week...promoting more moisture advection into
the region through the weekend.

&&

.AVIATION...Mostly VFR conditions are expected across the local
flying area during the morning hours. However, brief trade wind SHRA
will continue to cause vicinity SHRA across the Leeward, USVI and
TJSJ taf sites thru 08/16Z. After 08/18Z SHRA will develop across
western PR with isolated MVFR CIGS/VSBYS and mountain obscurations
affecting TJBQ and possibly TJMZ. Surface winds will remain mostly
from the east at 10 to 15 kts.

&&

.MARINE...High risk of rip currents across the northern coast of
PR as well as some beaches in northern Culebra and north and east
Saint Croix. Seas will be up to 6 feet today, small craft should
exercise caution. Seas are expected to deteriorate by early
Tuesday.The combination of a large swell event and increasing
winds will generate dangerous marine conditions from Tuesday through
at least the next weekend. Mariners and beachgoers should pay
close attention to our local forecast.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 83 74 80 / 30 40 40 40
STT 73 84 73 84 / 40 40 50 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
423 AM AST Mon Jan 9 2017

.SYNOPSIS...An upper level ridge will continue to erode rapidly
today as a deep polar trof amplifies southeastward over the
southwestern Atlantic. A strong surface high pressure moving
across the eastern United States seaboard will push an associated
frontal boundary/shear line across the region late today and
Tuesday. TUTT will develop well northeast of the area early in the
week.

&&

.DISCUSSION...Under a northeast low level wind flow, Doppler
weather radar detected brief isolated to scattered showers moving
rapidly across the USVI, Vieques, Culebra as well as across the eastern
and northern sections of Puerto Rico. This activity will continue
for the rest of the morning hours. No significant precipitation
was observed elsewhere over land areas so far this morning.
Cloudiness is expected to increase across the region today and for
the next several days. This moisture in combination with local
effects will induce the development of scattered showers across
interior, western and southwest sections sections of Puerto Rico
this afternoon.

Satellites images as well as model guidance depicted a deep polar
trof amplifying across the eastern United States. This feature
will continue to amplify southeastward over the Southwestern
Atlantic today and Tuesday. A strong surface high pressure is
expected to develop today over the eastern United Stated
seaboard. As this happens, an associated frontal boundary/shear
line will be pushed across the local islands late today and
Tuesday.

This feature will induce an increase in moisture across the
region for the next several days. Northeast winds are expected to
increase even more tonight and for the next several days. These
northeasterly wind flow will transport areas of cloudiness and
showers across the local islands for most part of the week. A
broad area of low pressure is forecast to develop to the
northeast of the local islands by the end of the week.

&&

.AVIATION...VFR conds across the local flying area durg prd.
However, brief trade wind SHRA and prds of SCT-BKN cld lyrs nr
FL025...FL050...FL090 en route btw islands from time to time. VCSH
across the Leeward islands, USVI and TJSJ taf sites til 09/14Z. Aft
09/17Z...SHRA mainly over ctrl interior and W-SW PR with brief MVFR
psbl mainly with SHRA and CIGS nr FL025. Brief mountain top obscr
ovr parts of central mountain range of PR mainly w/SHRA and few low
clds. Surface winds lgt/vrb bcmg mainly fm E-NE 10-15 kts aft 09/14z.

&&

.MARINE...Seas are expected to deteriorate rapidly tonight. The
combination of a large swell event and increasing winds will
generate dangerous marine conditions from tonight through at
least the next weekend. Small craft advisories will go into effect
as soon as tonight. A High Surf Advisory may be required by early
Tuesday. Mariners and beachgoers should pay close attention to our
local forecast.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 73 81 73 / 40 40 40 30
STT 84 73 84 73 / 40 50 50 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
201 PM AST Mon Jan 9 2017

.SYNOPSIS...A frontal boundary over Hispanola will weaken during
the next few days as it moves eastward over the local area. This
front will bring additional cloudiness and showers to the local
islands through midweek. In the wake of the front...strong surface
high pressure over the Western Atlantic will create breezy to
windy conditions through the end of the week.

&&

.DISCUSSION...Satellite derived precipitable water analysis showed
a cold front extending from Hispanola northeastward into the
Central Atlantic. This boundary will continue to approach the
area from the west...increasing the cloudiness and the chances of
showers over the next few days. The pre-frontal trough associated
with this boundary is moving across the local area today. As a
result...scattered showers have moved inland across portions of
Puerto Rico and the U.S. Virgin Islands since early this morning.
A mixture of sun and clouds with scattered showers will continue
the rest of today.

The frequency of passing showers and clouds will increase on
Tuesday and Wednesday as frontal boundary moves over the local
islands enhancing the moisture convergence. After the front
crosses the region...moisture and temperature drop across the
Northeast Caribbean Region. Temperatures are forecast to decrease
between 3-5 degrees below normal. Our current forecast calls for
minimum temperatures in the low to mid 50s at high elevations and
low to mid 70s at lower elevations on Wednesday Night and Thursday
Night. Drier than normal air mass will keep the chance of shower
low for the second part of the week.

&&

.AVIATION...SHRA activity expected to increase across the flying
area of PR through this evening, as a pre-frontal trough moves
across the region. Prds of MVFR conds due to SCT-BKN cld lyrs btwn
FL025-FL090 expected from time to time across TJSJ/TIST/TJPS/TJBQ.
The NE wind flow will bring clouds and -SHRA after 09/23z across
TJSJ/TJBQ/TIST. Surface winds mainly from the NE at 5 to 15 knots
bcmg calm to light and variable aft 09/23z.

&&

.MARINE...Marine conditions will continue to deteriorate through
midweek as a NNW swell invades the regional waters on Tuesday. In
addition, winds are forecast to increase to around 20 kt from
midweek through Friday. Therefore, Small Craft Advisories are in
effect tonight. In addition, High Surf Advisory is in effect from
early Tuesday Morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 81 73 80 / 40 40 30 30
STT 73 84 73 83 / 50 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
449 AM AST Tue Jan 10 2017

.SYNOPSIS...A deep polar trof will continue to amplify southeastward
over the southwestern Atlantic and the local Atlantic waters today.
A surface high pressure centered over the northwest Atlantic will
push an associated weak frontal boundary, southeastward across
the local islands. After the frontal boundary passage, a strong
northeast wind flow will induce breezy conditions across the
region for the next several days.

&&

.DISCUSSION...Under a northeast low level wind flow, Doppler
weather radar detected isolated to scattered showers moving
rapidly across the USVI, Vieques, Culebra as well as across the
eastern and northern sections of Puerto Rico. Due to the rapid
movement of the showers the total rainfall accumulations were
generally minimal. This activity will continue for the rest of
the morning hours. Cloudiness is expected to increase across the
region today as a weak frontal boundary moves across the region.
This moisture in combination with local effects will induce the
development of scattered showers across interior, western and
southwest sections sections of Puerto Rico this afternoon.

Latest satellites images as well as model guidance depicted
a frontal boundary extending from the Caribbean waters across
Hispaniola and then northeastward across the central Atlantic for
several hundreds miles. A surface high pressure centered over the
northwest Atlantic will push the frontal boundary across Puerto
Rico and the U.S. Virgin Islands today and tonight. This feature
will induce an increase in cloudiness and showers coverage across
the region until at least Wednesday.

A moderate to strong northeast low level winds, expected with the
passage of the frontal boundary will continue to transport
occasionally areas of cloudiness and showers mostly across the
U.S. Virgin Islands, Vieques, Culebra and across the northern and
eastern sections of Puerto Rico overnight and early in the
mornings with some convection expected to develop during the
afternoons across western, interior and southwest sections of
Puerto Rico until at least Wednesday. Moisture is expected to
decrease sharply after the frontal boundary passage. A northeast
wind flow in combination with a dry air mass expected across the e
region by wednesday will induce cooler than normal temperatures
across the local islands.

&&

.AVIATION...Passing SHRA activity expected to continue across the
area PR and USVI this morning. Winds are expected to continue from
the NE and increasing after 10/12Z. Winds could be as much as
20KT sustained with higher gusts after 10/16Z.

&&

.MARINE...Latest bouy observations indicated swell actions across
the Atlantic waters with buoy 41043 located around 180 miles
northeast of San Juan showing seas up to 11 feet with periods of
11 seconds, San Juan bouy 41053 indicated seas up to 8 feet with
period of 12 seconds and Rincon buoy 41115 indicated seas up to 11
feet with period of 12 seconds. Seas are expected to increase even
more this morning. Therefore SCA is in effect for all coastal
waters. Refer to latest Coastal Hazard Message (CFWSJU) and
Coastal waters forecast (CWFSJU) products for latest information
and other marine advisories.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 74 80 73 / 40 30 30 20
STT 83 73 82 72 / 50 30 30 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
300 PM AST Tue Jan 10 2017

.SYNOPSIS...A cold front between Dominican Republic and the Mona
Passage will move over the local area tonight. The frontal boundary
will bring additional clouds and showers to the local islands the
rest of today and Wednesday. Then, strong surface high pressure
will build over the Western Atlantic...creating breezy to windy
conditions through the end of the week.

&&

.DISCUSSION...Surface analysis as well as satellite derived
precipitable water analysis indicated a cold front extending from
the Mona Passage to the Central Atlantic. This boundary will move
over the local islands later today into Wednesday Morning. The
frequency of passing showers and clouds will increase over the
Puerto Rico and the U.S. Virgin Islands as frontal boundary moves
over the local islands over the next 24 hours. When the front
moves south of Puerto Rico...moisture and temperature drop across
the local region. Temperatures are forecast to decrease below
normal Wednesday night and Thursday night. Minimum temperatures
will generally range in the mid 50s at high elevations and mid to
upper 70s at coastal locations. Drier than normal air mass will
limit the shower development the second part of the week.

&&

.AVIATION...Passing SHRA activity expected to continue across
mainland Puerto Rico, this afternoon. MVFR conditions due to brief
bkn ceiling are possible across TJBQ,TJMZ, TJSJ. Overnight, another
round of -SHRA/SHRA are expected across all TAF sites except over
TJPS. This SHRA will be accompanying with gusty winds up to 30 kts.
NE winds could be as much as 20KT sustained with higher gusts mainly
at TJBQ while the rest of the terminals expected mainly 10-20KT and
gusty.

&&

.MARINE...Large NNW swell will continue to produce hazardous marine
conditions across the regional waters through the end of the week.
Small Craft, High Surf and Coastal Flood Advisories are in effect
along the coastal areas facing the Atlantic Ocean. In addition,
there is a high risk of Rip Current for most of the beaches in
Puerto Rico and . For additional information about the current
situation refer to the local marine products.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 80 73 79 / 30 30 20 20
STT 73 82 72 83 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
505 AM AST Wed Jan 11 2017

.SYNOPSIS...High pressure in the western Atlantic has brought a
cold front through Puerto Rico and the U.S. Islands with strong
winds, and hazardous marine conditions that will last through at
least the end of the week.

At upper levels...A jet of up to 95 knots will prevail over the
local area through at least Sunday. High pressure will begin
ridging north over Hispaniola until a weak short wave moves
through on Monday.

At mid levels...Low pressure will cut off about 880 miles
northeast of San Juan today moving only about 400 miles southeast
through Friday sending a trough through the area. High pressure
then spreads over the area from the western Caribbean and
continues through the end of next week. Mid levels remain very dry
until Tuesday of next week.

At lower levels...A cold front has passed through the area and
north to northeast flow will continue due to persistent high
pressure in the western Atlantic. Low pressure will deepen about
880 miles northeast of San Juan and play an important role in wave
production for the area, but it will move south and dissipate by
Sunday leaving only a broad stretch of northeasterly winds around
the high by next week.


&&

.DISCUSSION...Winds have continued over the area`s waters with
some stronger winds making it onshore with showers. San Juan had
gusts to 37 mph overnight and 53 hundredths of an inch of rain
since 6 PM AST Tuesday. Showers will continue on the windward side
of the islands through the day with some showers able to cross
through. The back edge of the frontal band moisture is expected to
be through Puerto Rico by evening, but GFS time-height sections
over the area show rich shallow low-level moisture persisting
through much of the forecast period. Flow gradually becomes more
easterly during the next 7 days, but moisture patches continue and
will yield isolated to scattered showers. Because of the long
fetch of winds behind the front and around the high pressure
marine conditions will be the most prominent weather features
through the rest of the week. After a lull tonight, 850 mb winds
will increase to over 30 knots Friday afternoon according to the
GFS and so surface winds will follow suit to a lesser degree.
Winds gradually subside over the week following.

Expect Thursday morning to be the coolest of the next 10 days with
warming of the 1000 to 850 mb layer through Friday followed by
little change in minimum and maximum temperatures.


&&

.AVIATION...BKN-OVC cld lyrs nr Fl022...Fl050...FL080 assocd with
remnants of old frontal boundary will cont to sink southwards
across the flying area durg the nxt 24 hrs. Periods of SHRA, with
ocnl gusty northerly Sfc winds up to 30 kts mainly across the ATL
coastal water and northern half of PR and USVI til at least
11/15z. TEMPO MVFR conds psbl with the passing SHRA. Recent VAD
wind profile from the doppler weather radar TJUA suggest llvl winds
btw 15-25 kts below FL200...bcmg W and increasing with height abv
to max wnd of 70-80 kts nr FL360.

&&

.MARINE...Winds and seas will increase through Saturday with seas
of at least 12 feet in portions of the local Atlantic waters by
Saturday. This is mainly due to a second pulse of swell generated
by the low forming northeast of the area that will arrive early in
the weekend. Small Craft Advisories will remain in all exposed
waters through at least the weekend. Periods will subside from
around 12 seconds after Thursday. Rip current risk is high on
most northern beaches. Wave penetration in normally quiet passages
has been better than models have forecast and even the Vieques
buoy has been running 8-9 feet. Had to make some manual adjustment
in the grids there. Have extended Rip Current risk and high surf
out through 8 AM AST Friday morning to better reflect the
longevity of this event.

Coastal Flooding is likely with strong onshore flow and tides that
will peak at around 1.8 feet most everywhere before 8:30 AM today.
Although a secondary high tide will occur this evening it is only
about half as high. But, another similar high tide will occur
Thursday and Friday, with some threat of minor coastal flooding
on northern shores each of these mornings.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 74 82 75 / 50 20 20 20
STT 84 74 85 75 / 50 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
222 PM AST Wed Jan 11 2017

.SYNOPSIS...Cold front over the local region will continue to fade
through Thursday. In the wake of the front...strong high pressure
over the Western Atlantic will maintain breezy condition and push
a drier and cooler air mass over the local islands during the next
few days. Although moisture will remain below normal the rest of
the week, brisk northeasterly flow will bring scattered showers
over the leeward side of the islands at times.

&&

.DISCUSSION...Satellite and radar imagery have been indicating
showers associated with the frontal bondary moving across the
local islands today. The rapid movement of these showers have
limited the rainfall accumulations. The frequency of the showers
will decrease tonight into Thursday Morning as the front moves
over the Caribbean Waters. Fair weather pattern is forecast for
all the islands on Thursday...with mostly sunny skies and little
or no shower activity. Breezy conditions will prevail across the
region the rest of the week as strong high pressure north of the
area and surface low pressure over the Central Atlantic keep the
gradient tight.

Upper level trough will swing over the local area on Friday...
increasing the convective instability across Puerto Rico and the
U.S. Virgin Islands. The trade wind cap will hold...however some
enhancement in the trade wind showers is anticipated across the
northern and eastern half of Puerto Rico. Then...fair weather
pattern will return to the local islands as moisture will drop
below normal during the weekend.

&&

.AVIATION...BKN-OVC cld lyrs nr Fl022...Fl050...FL080 assocd with
remnants of old frontal boundary will cont to sink southwards
across the flying area durg the nxt 24 hrs. Periods of SHRA, with
ocnl gusty northerly Sfc winds up to 30 kts mainly across the ATL
coastal water and northern half of PR and USVI til at least
11/15z.TEMPO MVFR conds psbl with the passing SHRA. Recent VAD wind
profile from the doppler weather radar TJUA suggest low leveL winds
btw 15-25 kts below FL200...bcmg W and increasing with height abv to
max wnd of 70-80 kts nr FL360.

&&

.MARINE...Large northerly swell will continue to produce hazardous
marine conditions across the regional waters through early next
week. Small Craft, High Surf and Coastal Flood Advisories are in
effect across the Atlantic Coasts of the local islands. No significant
improvement is anticipated over the next 5-7 days as strong winds
will continue to create rough seas and large breaking waves along
the Atlantic coasts.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 82 75 83 / 20 20 20 20
STT 74 85 75 86 / 20 20 20 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
517 AM AST Thu Jan 12 2017

.SYNOPSIS...High pressure in the western Atlantic has driven a
cold front south of the area. Strong winds will persist into next
week with isolated to scattered showers throughout the period over
smaller islands and the mountains and windward plains of Puerto
Rico.

At upper levels...A weak ridge over the area will retrograde into
the central Caribbean by Saturday. A weak trough will pass through
on Monday with flow turning almost due north by mid week next
week.

At mid levels...A trough will extend into the eastern Caribbean on
Saturday from a dissipating cut-off low now northeast of the area
and continue through mid-week next week. High pressure just north
of Cuba will drop southward next week into the western Atlantic.
Except for a few patches of modest moisture Tuesday through
Thursday of next week, mid-level moisture will be nearly absent.

At lower levels...High pressure has driven a cold front through
the area and it is now over the open Caribbean. High pressure will
dominate the weather pattern through the end of next week. Low
pressure about 750 miles northeast of the area will sink south
through Saturday tightening gradients and keeping northeast winds
over the area strong. Patches of shallow moisture will move
through the area on strong winds this week and next week bringing
shallow, isolated to scattered showers with the best amounts over
interior Puerto Rico. Flooding should not be expected.

&&

.DISCUSSION...NWS doppler radar showed many small showers moving
south southwest at about 20 knots over much of the surrounding
waters and well into interior Puerto Rico. A few showers were also moving
around the U.S. Virgin Islands.

Models are showing a gradual increase in the 850 mb winds from
around 20 knots to as much as 32 knots on Friday night. This also
corresponds with an increase in the surface flow forecast. Winds
then continue at slightly reduced, but relatively strong
intensities, through Tuesday. Moisture values reached a 7-day
minimum this morning and will increase through Friday, although
precipitable water will remain under 1.5 inches for at least the
next 7 to 10 days. With similar but limited values of moisture--
mainly confined to the lowest 8000 feet of the atmosphere--showers
will be widely scattered, shallow, small in size and very brief,
with only a few hours of drier air to shut them down from time to
time. Two of those drier periods appear to occur Sunday night and
Tuesday morning, but models cannot be trusted to perfectly predict
something so ephemeral and we will not be able to trust the
timing here. The showers will yield the most over the interior
sections of Puerto Rico due to orographic forcing just as occurred
Tuesday and Wednesday, but all amounts will be light.

&&

.AVIATION...Mainly VFR expected across the local terminals with VCSH
occurring in quick passing SHRA. SFC winds will be mainly from the E
to NE at about 100-20 KT with even higher gusts. TJBQ and TJMZ may
be on the higher end of the range with winds around 20KT and gusting
to 30KT, TJPS in the lower end with winds close to 10KT and gusting
to about 15KT, the rest of the terminals will fall somewhere in
between.

&&

.MARINE...Winds and seas will increase through Friday night in our
northern waters. High tides will be in the mornings between 9 and
11 am each day through Saturday. These periods will be the time
when minor coastal flooding is likely to occur and would expect
that flooding to be the worst on Friday or Saturday mornings. For
this reason will not extend the coastal flood advisory beyond this
afternoon at 2 PM, but it may be re-issued for Friday morning.
High risk of rip currents and high surf are givens with seas
already at or above 10 feet in many Atlantic waters and passages.
Although conditions should begin to improve Saturday and Saturday
night, hazardous conditions, including small craft advisories, are
expected to continue well into the following week. For those
contemplating entering the waters, these are the most dangerous
conditions that have been seen in many months. It is best to
avoid the water or visit our sheltered beaches on the south side
of the island.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 75 83 74 / 30 50 50 50
STT 85 75 86 72 / 10 40 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
206 PM AST Thu Jan 12 2017

.SYNOPSIS...
A strong high pressure across the Atlantic Ocean will maintain
breezy conditions. This system will result in pleasant
climatological temperature across the local islands during the
next few days. The northeasterly wind flow will bring patches of
low level moisture with embedded clouds and showers each day
mainly across the leeward side of the islands at times.

&&

.DISCUSSION...
Satellite imagery showed stratus cumulus clouds approaching the
islands from the Mid latitudes of the Atlantic Ocean. The strong
high pressure across the Atlantic Ocean is advecting clouds and
showers across the region. In addition, this surface high
pressure is producing a northeasterly wind flow between 15 and 25
mph with gusts up to 35 mph. Pleasant climatological temperatures
are forecast during the next few days with partly cloudy skies and
breezy conditions. This pattern is expected through at least the
upcoming weekend.

However, an upper level trough will swing over the local area on
Friday. As a result the potential for convective activity should
increase somehow on Friday across Puerto Rico and the U.S. Virgin
Islands. A stable weather pattern will return to the local
islands on Saturday, however trade wind showers can be expected
across the northern and eastern half of Puerto Rico and the U.S
Virgin Islands each day.

&&

.AVIATION...
VFR conds expected during the forecast period. SCT-BKN
cigs FL045-FL060. NE winds of 15-25 kt with gust of 30 kt will
prevail below FL150. No operational issues are anticipated the rest
of today.

&&

.MARINE...
Hazardous marine conditions continue across the regional waters.
No significant improvement in the marine conditions is anticipated
over the next 4-5 days. As a result...A High Surf, Coastal Flood
and Small Craft Advisory remain in effect through the end of the
week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 83 74 83 / 50 50 50 50
STT 75 86 72 86 / 40 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
514 AM AST Fri Jan 13 2017

.SYNOPSIS...Shallow moist air will continue to move across the
forecast area through at least the next 5 days bringing isolated
to scattered showers...mainly to windward plains and slopes of the
local islands. Fresh to strong northeast flow will turn more
easterly early next week.

At upper levels...Very weak high pressure will approach the area
through Sunday morning as a jet intensifies up to 100 knots
overhead. A weak trough moves through on Monday.

At mid levels...A cut-off low northeast of the Leeward Islands
weakens into a trough that extends into the northeast Caribbean
through Tuesday. As it weakens high pressure builds over the
western Caribbean and continues into the week after next. Mid
level moisture is absent except Monday through Wednesday when
limited amounts are present.

At lower levels... High pressure will continue across the western
Atlantic through the end of next week. It does weaken somewhat
during the latter half of next week. Low pressure about 800 miles
east northeast of Fajardo, Puerto Rico will fade into a trough in
the eastern tropical Atlantic over the weekend.

&&

.DISCUSSION...Numerous small showers have moved onshore in Puerto
Rico and the northern U.S. Virgin Islands with very slight
accumulations. These will continue as a band of moisture moves
into the area, spun off from the low pressure northeast of the
area that has been elongating along a northeast southwest axis
through Culebra. The best accumulations will likely be less than
one quarter inch today and will be concentrated over the mountain
interior of Puerto Rico. Shallow moisture will continue through
next week, and bands of drier air forecast by the GFS are not as
prominent during the next 5 days as they had been in prior
forecasts. So, isolated to scattered showers will continue with
periods of sun.

Winds are expected to increase through early tonight with 15 to 25
mph and gusts up to at least 30 over local waters and exposed
coastal areas of the islands. Winds slowly abate Sunday through
the end of next week as they turn more easterly early next week.


&&

.AVIATION...Showers embedded in the northeasterly trades will
continue to induce brief periods of SHRA over the Leeward, USVI and
TJSJ taf sites until at least 13/16Z. Mostly VFR conditions are
expected across the rest of the local flying area with only VCSH.
After 13/17Z some SHRA are possible across TJMZ and TJBQ. Low level
winds will continue mainly northeast at 15 to 20 kts with higher
gusts.

&&

.MARINE...Winds and seas are still forecast to peak early tonight
and then subside only slowly into next week. Small craft advisory
conditions will continue in most waters exposed to northeast swell
through mid week next week. Expect coastal flooding to peak this
morning but continue longer as seas increase during the day.
Coastal flooding is likely to return Saturday morning when tides
return to nearly the same levels as the last several days. High
surf will increase through the day and breaking waves will
approach 18 feet along many northern coasts by early tonight. As
it was said yesterday, it will be best to keep a safe distance
from the ocean today and tomorrow on the northern, northwestern
and northeastern coasts. Southern coasts will be much more
tranquil in Puerto Rico.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 76 83 75 / 50 50 60 60
STT 84 75 84 74 / 30 40 40 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
202 PM AST Fri Jan 13 2017

.SYNOPSIS...Surface low pressure northeast of the Leeward island
is expected to weaken and dissipate by Saturday morning. Surface
high pressure across the northwestern Atlantic will keep fresh to
locally strong northeasterly winds across the local area for the
next few days.

&&

.DISCUSSION...Fresh to strong winds from the north northeast
prevailed today and it is expected to do so for the next few days.
A few showers were observed through the day but mostly in the
morning hours then becoming less frequent as the day progressed.
The 12Z sounding indicated that the available moisture was really
limited to the lower levels of the atmosphere and the forecast
soundings indicate that a fairly dry airmass will continue over
the area with the limited moisture also in the lower levels for
the next few days and with precipitable water values generally
under 1.25 inches.

This pattern should give us scattered to locally numerous showers
in the overnight hours with isolated to scattered showers during
the day across the northern half and eastern PR as well as
Vieques, Culebra, and the U.S. Virgin Islands.


&&

.AVIATION...VFR conds expected at all terminals. However, brief MVFR
cigs still possible at times with passing -SHRA. SCT-BKN cigs
between FL025-FL065. NE winds of 15-25 kts.. No operational impacts
are anticipated through the forecast period.


&&

.MARINE...Northerly swell will continue affecting the local waters
for the next few days. Seas are still expected to continue to be
hazardous through the weekend and into the early part of next
week. Small craft, High Surf, and Coastal flood advisories
continue in effect. Local nearshore buoys are currently reporting
seas between 8 and 11 feet with a period of about 13 seconds.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 83 75 84 / 50 60 60 60
STT 75 84 74 85 / 40 40 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
613 AM AST Sat Jan 14 2017

.SYNOPSIS...
A fresh to strong northeasterly wind flow will continue to bring
patches of low level moisture, with clouds and passing showers
across the forecast region during the weekend. Most of the shower
activity is expected to focus across the U.S. Virgin Islands and
to the North of the Cordillera Central. An upper level trough is
forecast to move across the region by early next week.

&&

.DISCUSSION...
Showers embedded in the northeasterly wind flow prevailed
overnight across the local waters, the U.S. Virgin Islands and
to the north of the Cordillera Central of Puerto Rico. This
activity moved fast enough to produce less than half an inch.
However, periods of moderate to heavy rains were detected with the
Doppler Radar.

Under the fresh to strong northeasterly wind flow continue to
expect passing showers and pleasant temperatures across the
islands. This pattern is expected during the next few days, with
patches of low level moisture bringing periods of clouds and
showers over the islands. But, temperatures will begin to warm
slightly and be near normal for January. Model guidance are
indicating the arrival of an upper level trough across the region
by early next week.

&&

.AVIATION...
Mainly VFR conditions are expected to prevail across all
TAF sites through at least 15/02Z. But, many fine showers moving
across the area from the northeast at 25 to 30 knots. Sfc winds 8 to
18 kt with higher gusts. Maximum winds expected 260/85 at
FL410 at 15/00Z.

&&

.MARINE...
Hazardous marine conditions continue across the Atlantic waters
and Caribbean Passages. As a result small craft, high surf and
coastal flood advisories continue in effect for various coastlines
of Puerto Rico and the U.S. Virgin Islands. Hazardous seas are
expected at least until early next week. Seas up to 12 feet with
occasional seas up to 15 feet are expected across most of the
local waters. Seas up to 6 feet are expected across the Caribbean
Coastal waters of Southern Puerto Rico. Beachgoers are urged to
avoid the northern beaches of the islands through at least early
next week. Please refer to the marine products for additional
information.

&&

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 75 84 75 / 40 40 40 40
STT 84 73 85 75 / 30 30 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
141 PM AST Sat Jan 14 2017

.SYNOPSIS...Surface low pressure and associated trough across the
central Atlantic, and High pressure across the west Atlantic will
continue to induce moderate to strong northeast winds across the
northeastern Caribbean. The low is forecast to later lift farther
northeast as the surface high builds across the western Atlantic.
Broad mid to upper level trough north and east of the region will
linger through the weekend. The upper trough is forecast to weaken
by the latter part of the upcoming week as a mid to high pressure
ridge will build across the western Atlantic. In the meantime a
short wave trough will round the base of this upper trough late
Sunday through Monday.

&&

.DISCUSSION...Scattered to isolated showers continued to affect
the coastal waters and portions of the islands during the day.
Under the moderate to strong northeasterly wind flow, the overall
pattern was unchanged from recent days with mainly the northern
half and eastern PR experiencing periods of quick passing showers.
Northeast winds of between 15 to 20 mph prevailed with occasionally
higher gusts between 30 to 35 mph in isolated areas. Max temps were
in the low to mid 80s across the lower elevations and in the 70s
across the higher elevations.

During the late evening and overnight...no significant change in
the overall synoptic pattern is forecast. Expect similar weather
conditions with periods of passing low clouds and showers mainly
across the northern half of the islands. Recent TJSJ 14/12Z upper
air sounding as well as latest model forecast guidance both suggest
prevailing winds below 500 millibars to continue from the northeast
between 20 to 30 mph. As a result, expect the intermittent periods
of shower activity to continue to move inland across parts of the
interior and east sections of the islands. Some showers will bring
periods of moderate to locally heavy downpours as well as brief
wind gusts. Clearing skies by late morning on Sunday ...becoming
mostly sunny with only brief passing showers expected for the rest
of the day. A short wave trough is still expected to quickly move
across the region late sunday into Monday, but at this time only
expect brief periods of passing showers as previously mentioned.

During the latter part of the upcoming week, the high pressure
ridge is to build just west of the region and the upper trough is
to shift farther east of the area. Low level winds are by then
expected to become more easterly as the surface high pressure
ridge will spread eastward across into the central Atlantic and
the previously mentioned area of low pressure northeast of the region
lifts further north and weakens. Seasonal temperatures will continue
during the next several days.

&&

.AVIATION...VFR conditions expected through the forecast period with
brief -SHRA across the local terminals. SCT SHRA across the local
area is expected through the rest of the day but these are expected
to be brief over any one point and also expected to be light to
moderate. NE winds at about 15-20KT and gusty for the rest of the
day, decreasing slightly to 10-15KT tonight.


&&

.MARINE...Marine conditions are still expected to be hazardous
for the next few days with the latest marine model guidance and
observations both in agreement with the present conditions and
previous forecast. The local buoys continued to report seas of
9-11 feet with a periods between 11-13 seconds today. Therefore
these hazardous marine conditions will continue to produce strong
breaking waves and dangerous rip currents. Please refer to the
latest Coastal waters forecast, Marine weather message and surf
zone forecast issued by the National Weather Service WFO San Juan
PR for additional information.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 84 75 83 / 40 40 40 40
STT 73 85 75 83 / 30 30 40 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
552 AM AST Sun Jan 15 2017

.SYNOPSIS...Broad surface high will continue to dominate the local
weather pattern for the next several days. A weak area of low
pressure will move quickly across the Atlantic as the surface high
continues to build having little to no impact on the local weather
conditions. Another surface low and associated frontal boundary is
forecast to reach the local area by the end of next week. Short
wave trof will continue through Tuesday as mid to upper level
ridge builds from the west.

&&

.DISCUSSION...Partly cloudy skies were observed across the islands
as trade wind showers on a brisk northeasterly flow moved from
time to time over portions of the U.S. Virgin Islands and the
northern half of Puerto Rico. Rainfall amounts were generally
less than a quarter of an inch. For today, forecast soundings are
indicating PWAT values under 1 inch as a dry mid level air mass
filters across the region from 12z-00z. Therefore, mostly sunny
skies with a few clouds can be expected today across the region.

As the strong surface high continues to build across the western
Atlantic and into the local area...breezy condtions and seasonable
temperatures will continue for the next several days. Short wave
trof aloft is not expected to have a significant impact on the
trade wind cap. However, strong northeasterly wind flow will
continue to bring patches of low level clouds and brief showers at
times across the islands.

&&

.AVIATION...Shallow moist flow from NE at 15 to 25 kt will cont at
LLVLS thru 16/12z carrying small SHRA that will come into the VCNTY
of all TAF sites except TJPS. Nevertheless mostly VFR conditions
will prevail across all TAF sites except for areas of mtn
obscurations til 15/18z. Sfc winds 8 to 15 kt with gusts to 25 kt
psbl in SHRA. Maximum winds will be at FL400 270/90 kt at 15/06Z.

&&

.MARINE...Hazardous marine conditions will continue through at
least Wednesday as northeasterly swell and wind driven seas
slowly subsides across the Atlantic waters and passages. Life
threatening rip currents due to large breaking waves continues
across the northern beaches of the islands. Seas will continue
today between 8-10 feet and northeasterly winds around 20 knots
are also expected to continue across most of the waters.


&&

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

[cycloneye]

AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
140 PM AST Sun Jan 15 2017

.SYNOPSIS...
Broad mid to upper level trough will continue north of the region
through Monday. This trough is to then become amplified across the
northern leewards and the eastern Caribbean by Tuesday. It is forecast
to linger through the end of the upcoming week, as high pressure will
build across the western Caribbean and eastern sea board of the
United States. Surface high pressure ridge extending across the
northeast Caribbean from the north central Atlantic along with and
an area of low pressure across the northeastern Atlantic will
maintain a dominant northeast wind flow across the region today.
Winds are however to become more easterly during the upcoming week
as surface high pressure will build and spread across the west and
central Atlantic. The local pressure gradient is also expected to
loosen resulting in a diminishing of the east to northeast trades.

&&

.DISCUSSION...Moderate northeasterly winds prevailed today across
the region with occasional gusty winds and occasional passing
showers . Some showers continued to move southwest across the
local waters and reach the inland portions of the islands from
time to time. Periods of moderate to locally heavy downpours were
observed and reported across portions of the interior and west
sections of Puerto Rico. The shower activity however was of short
duration with no significant rainfall accumulation or flood problems
noted today.

For the rest of the evening and overnight hours expect the
northeast winds to to persist but are to become more more
easterly as the high shifts farther east across the Atlantic, and
the area of low pressure lift farther north. In the meantime
patches of shallow low level wind moisture and passing showers
will still be possible during the overnight and early morning
hours.

On Monday, skies will become mostly sunny with moderate easterly prevailing
trade winds. Early and late morning showers will be focused across parts
of northern PR followed by lesser showers during the afternoon. The
afternoon activity should be focused mainly over parts of the interior
and south west sections of PR. Mostly fair skies and a stable weather
pattern is so far forecast for the latter part of next week, as high
pressure and a drier air mass will prevail across the region.

&&

.AVIATION...VFR conds expected through the period. Winds from the
east to ENE expected to persist at 10-20KT and gusty through 16/00Z.
Sct SHRA will cause at least VCSH with some SHRA briefly affecting
the terminals. The overall pattern is expected to continue through
tonight but the winds are expected to diminish some after 16/00Z
and increase once again after 16/13Z.

&&

.MARINE...Local buoys continued to indicate that the seas are
gradually diminishing but still remain choppy and hazardous.
Small Craft advisories remain in effect for most of the coastal
waters due to a slowly fading northerly swell and the moderate to
locally fresh northeasterly trade winds. High surf advisory, and a
high risk of rip currents also remain in effect for mainly the
north facing beaches of most of the islands. Please refer to the
latest Coastal Waters Forecast, Marine Weather Message and Surf
Zone Forecast issued by the National Weather Service WFO San Juan
PR for additional information.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 84 75 83 / 30 40 40 40
STT 75 83 75 84 / 40 40 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
555 AM AST Mon Jan 16 2017

.SYNOPSIS...High pressure across the western Atlantic will
maintain a fresh northeast wind flow across the local region
through Wednesday. High pressure will weaken at the end of the
week as a deep surface low pressure moves across the western
Atlantic.

&&

.DISCUSSION...Passing showers were observed across the local area
overnight. Most shower activity was observed across the Caribbean
coastal waters. Local area continue to be dominated by a surface
high pressure system which is located across the western Atlantic.
This high pressure system will continue to produce fresh northeast
winds across the local area through at least Wednesday. Therefore,
passing showers will continue to affect the local area from time
to time.

By the later part of the work week, the aformentioned high
pressure system is expected to weaken, which will allow for a
relax in the pressure gradient. As a result, winds will diminish
considerably by Friday. Under a mid to upper level ridge,
relatively fair weather conditions are expected without any
significant weather events affecting the region. Temperatures will
remain very pleasant, with minimum temperatures expected to drop
to the mid to upper 50s by the later part of the work week, as
clear skies are anticipated and winds will be light and variable.

&&

.AVIATION...Mostly VFR conditions expected through the forecast
period. Some passing showers are expected over TIST and TJSJ from
time to time. Low level winds will continue mainly ENE at 10 to 15
kts with higher gusts, mainly in showers.

&&

.MARINE...Latest buoy observations are showing seas between 5 to 7
feet with occasional seas up to 8 feet mainly across the offshore
Atlantic waters. Seas are expected to diminish gradually next few
days. However, marine conditions will continue hazardous through
at least Wednesday. High Surf advisory was cancelled as breaking
waves of 10 feet are no longer expected. Small Craft advisories
will continue in effect through at least Wednesday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 74 82 73 / 40 30 30 20
STT 84 72 83 71 / 40 30 30 20

&&

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
205 PM AST Mon Jan 16 2017

.SYNOPSIS...surface high pressure will remain causing a moderate
to fresh east-northeasterly wind flow for the next several days
before a surface low enters the western Atlantic on Thursday and
disrupts the pattern, causing the local winds to diminish
significantly. Drier air moving in and an upper trough across the
east to northeast of the local islands will maintain a mostly fair
weather pattern with limited rainfall for the next several days.

&&

.DISCUSSION...A few showers were observed today but slowly the
conditions improved over land while the showers persisted over the
Caribbean waters under an east northeast wind flow. Drier air is
moving in and the cloud development over land areas was modest. No
rainfall was observed over land areas late in the morning and the
early afternoon hours but we cannot rule out brief showers across
SW-PR although with the dry air advection those afternoon showers
are expected to be brief if any were to develop. For tonight and
the next couple of days the pattern is expected to continue like
it has been for the past few days but maybe slightly drier,
isolated to scattered showers in the overnight hours and early
morning while little shower activity in the afternoon. This
pattern should continue through Wednesday.

Thursday and the latter part of the workweek, a surface low moves
into the western Atlantic. This low will weaken the SFC high and
the local winds will diminish significantly. The local
temperatures are expected to remain near normal but with the
lighter winds on Thursday there may be cooler temps during the
night on the latter part of the week.


&&

.AVIATION...VFR conds durg entire prd. L/lvl Winds fm E-NE BLO
blo FL200 at 15-20 kts bcm fm W and incr w/ht abv to max wnd of 80-
85 kts nr FL390. SFC wnd fm NE 15-20kt w/ocnl gust 25-30 kts psbl
bcmg 10-15 kts aft 17/00z. Passing SHRA en route btw islands and at
terminals along N PR, around USVI,TKPK and TNCM. SCT-BKN clds nr
FL025...FL050...mostly CLR abv.


&&

.MARINE...Local buoy data suggest winds at around 15 knots while
NE swell continue to slowly subside across the coastal waters and
local passages. Seas of up to 8 feet are still possible across the
offshore Atlantic waters while the nearshore waters are generally
between 6 and 7 feet. Small craft advisories are still in effect
but if the diminishing trend continues over the next several hours
the advisories for the nearshore waters could be canceled. There
is still a high risk of rip currents for most of northwest to
north and east facing beaches of PR, vieques, Culebra and the
USVI.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 74 82 73 / 40 30 30 20
STT 84 72 83 71 / 40 30 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
520 AM AST Tue Jan 17 2017

.SYNOPSIS...High pressure across the western Atlantic will move
east as a intense low pressure system exits the U.S. east coast
Wednesday into Thursday. A east to east northeast wind flow will
continue to dominates the local region. Winds will diminish
considerably next few days.

&&

.DISCUSSION...Periods of passing showers prevailed across the
local islands overnight. Showers affected the eastern half of
Puerto Rico with rainfall accumulation less than half inch. An
east to east northeast wind flow will continue to prevail today.
These winds will transport showers across the region from time to
time. Local area will continue to be dominated by a high pressure
system which is located north of the area over the western
Atlantic. This high pressure is expected to weaken next couple of
days as a deep surface low pressure area moves across the western
Atlantic, eroding the high pressure. As a result, winds are
expected to diminish significantly especially after Thursday. No
major changes in the weather pattern is expected next several days
as relatively dry weather conditions are expected to continue
across the local area.

&&

.AVIATION...Mostly VFR conditions are expected across the local
flying area however, a few passing -SHRA/SHRA expected across TAF
sites at times. Winds expected from the E/NE at around 10 kt
increasing at 15 to 20 kt and gusty aft 17/12z.

&&

.MARINE...Seas will continue to gradually subside later today into
Wednesday. Seas up to 7 feet and winds up to 20 knots are expected
to continue through Wednesday morning.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 73 81 71 / 30 30 30 10
STT 84 72 82 70 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
151 PM AST Tue Jan 17 2017

.SYNOPSIS...Surface high pressure will remain causing a moderate
to fresh east-northeasterly wind flow until Wednesday before a
surface low enters the western Atlantic Late Wednesday and
weakens the surface High pressure, disrupting the current pattern
and causing the local winds to diminish significantly. Relatively
dry air moves in and an upper trough across the east to northeast
of the local islands will maintain a mostly fair weather pattern
with limited rainfall for the next several days, than a broad
upper level bridge dominates the area towards the end of the
workweek.

&&

.DISCUSSION...Some showers were observed in the early morning
hours, some of them moderate over NE PR, but after mid morning
very few showers were observed while the conditions improved over
land even though some showers persisted over the local waters
under an east northeast wind flow. Since relatively dry air is
moving in, only isolated to locally scattered showers are expected
this afternoon across northern, western and SW-PR. For tonight
and Wednesday the pattern is expected to continue like it has
been for the past few days with isolated to scattered showers in
the overnight hours and early morning while little shower activity
in the afternoon.

For Thursday and the latter part of the workweek, it is still
likely that a surface low moves into the western Atlantic. This
low will weaken the SFC high and the local winds will diminish
significantly. The local temperatures are expected to remain near
normal but with the lighter winds on Thursday there may be cooler
temps during the night on the latter part of the week.

&&

.AVIATION...VFR conds will prevail entire prd. Few CU/SC clds lyrs
nr FL025...FL050...CLR abv. Low level wnds fm NE 15-20 kts blo
FL200...BCMG fm W abv and incr w/ht to max wnd btw 70-80 kts nr
FL400. Passing -SHRA/SHRA en route mainly ovr offshore Atl waters N
of islands. SFC wnd fm NE 10-15 kts w/ocnl gusts of 20-25 kts psbl
bcmg fm E 5-15kt aft 17/23z. No sig operational impacts attm.

&&

.MARINE...Local nearshore buoys are reporting seas of 4-6 feet
which is consistent with the local forecast. For that reason the
small craft advisory continues in effect for the offshore waters
until late tonight. High risk of rip currents also are in effect
until late tonight. Winds and seas are expected to significantly
improve starting late Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 81 71 81 / 30 30 10 10
STT 72 82 70 82 / 30 20 20 20