Caribbean - Central America Weather

[cycloneye]

Good morning. Scattered showers will once again move thru PR and VI today and will continue for the next few days.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
526 AM AST WED DEC 18 2013

.SYNOPSIS...RIDGE ALOFT EXTENDS ACROSS THE NORTHEASTERN CARIBBEAN
WHILE A POLAR TROUGH EXITS THE EASTERN SEABOARD OF THE UNITED STATES
AND BUCKS THE EASTERN PERIPHERY OF THE UPPER RIDGE. A TUTT LOW
AND ASSOCIATED TROUGH REMAINS ANCHORED JUST EAST OF THE LESSER
ANTILLES. A WEAKENING SURFACE FRONT EXTENDS SOUTHWARDS ACROSS THE
SOUTHWEST ATLANTIC THEN INTO THE WESTERN CARIBBEAN...WHILE A BROAD
SURFACE HIGH PRESSURE RIDGE EXTENDS ACROSS THE WEST AND CENTRAL
ATLANTIC FROM THE NORTH CENTRAL ATLANTIC. THE HIGH PRESSURE RIDGE
WILL MAINTAIN MODERATE TO INCREASINGLY STRONG EASTERLY TRADE WINDS
ACROSS THE REGION DURING THE NEXT SEVERAL DAYS.

&&

.DISCUSSION...THE PREVAILING EASTERLY TRADE WINDS WILL MAINTAIN
A FAIRLY MOIST ADVECTIVE WEATHER PATTERN ACROSS THE ISLANDS FOR
THE NEXT COUPLE OF DAYS. TUTT TO THE EAST OF THE ISLANDS CHAIN
WILL ALSO HELP TO ENHANCE THE EMBEDDED PASSING SHOWERS WHICH WILL
MAKE THEIR WAY TO THE ISLANDS AND COASTAL WATERS FROM TIME TO
TIME. PREVIOUS UPPER AIR DATA...LOCAL OBSERVATIONS AND SATELLITE
IMAGERY SUGGEST SLIGHT EROSION OF THE UPPER LEVEL RIDGE. THIS WILL
CONTINUE TODAY AS THE AFOREMENTIONED POLAR TROUGH CONTINUES EASTWARD
INTO THE NORTH ATLANTIC. AS THE RIDGE ALOFT ERODES...EXPECT THE TRADE
WIND INVERSION TO SLIGHTLY WEAKEN TODAY AND ALLOW FOR SEA BREEZE
CONVERGENCE TODAY IN SOME AREAS THROUGH AT LEAST THURSDAY AND
POSSIBLY ON FRIDAY. THEREFORE EXPECT BETTER POTENTIAL FOR DAYTIME
CONVECTIVE DEVELOPMENT. THEREAFTER...THE UPPER RIDGE REESTABLISHES
AND BUILDS ACROSS THE REGION ONCE AGAIN TO INCREASE THE TRADE WIND
INVERSION CAP BY THE UPCOMING WEEKEND.

THE BROAD SURFACE HIGH IS ALSO TO REESTABLISH AND BUILD ACROSS THE
WEST AND CENTRAL ATLANTIC BY THURSDAY. THIS IN TURN WILL TIGHTEN THE
SURFACE PRESSURE GRADIENT ONCE AGAIN...LEADING TO THE INCREASING
EASTERLY TRADE WINDS FOR THE WEEKEND. A RETURN OF THE MORE TYPICAL
TRADE WIND ADVECTION OF PASSING SHOWERS IS THEN FORECAST... WITH
PERIODS OF MAINLY LIGHT TO MODERATE SHOWERS MOVING ACROSS THE
REGION FROM TIME TO TIME ESPECIALLY DURING THE LATE EVENING AND
EARLY MORNING HOURS.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS MOST OF THE FLYING
AREA...WITH SOME PASSING VCSH OVER TJSJ...TIST...TISX...TNCM AND
TKPK AT LEAST DURING THE EARLY MORNING HOURS. SFC WND MAINLY FM
EAST AT 10 KT OR LESS THRU EARLY MORNING...WITH SOME HIGHER GUSTS
NEAR SHRA. AFTER 18/12Z PASSING SHRA/VCSH WILL CONTINUE TO AFFECT
VARIOUS TAF SITES BUT VFR CONDS EXPECTED TO PREVAIL WITH EASTERLY
LOW LEVEL WNDS AT 10 TO 20 KTS WITH SOME HIGHER GUSTS.

&&

.MARINE...BUILDING SURFACE HIGH PRESSURE ACROSS THE ATLANTIC
WILL RESULT LEAD TO INCREASING FRESH TO LOCALLY STRONG TRADE
WINDS ACROSS THE LOCAL WATERS...BEGINNING TONIGHT AND CONTINUING
THROUGH THE WEEKEND. THIS WILL PROMOTE CHOPPY AND HAZARDOUS SEAS.
SMALL CRAFT ADVISORIES WILL BE REQUIRED FOR PARTS OF THE LOCAL
ATLANTIC LATER TONIGHT...FOLLOWED BY MOST OF THE LOCAL WATERS ON
THURSDAY AND THROUGH THE UPCOMING WEEKEND. PLEASE REFER TO THE LATEST
COASTAL WATERS FORECAST AND MARINE WEATHER MESSAGE ISSUED BY WFO
SAN JUAN PUERTO RICO.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 82 74 / 30 30 40 40
STT 86 74 85 76 / 40 40 20 20

[cycloneye]

Good afternoon. Not much change from the actual pattern of trade wind showers moving thru PR and VI for the next few days.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
301 PM AST WED DEC 18 2013

.SYNOPSIS...UPPER LEVEL RIDGE ALOFT WILL CONTINUE TO ERODE TODAY AS
POLAR TROUGH MIGRATES INTO THE NORTH ATLANTIC. THEN...A LONGWAVE
TROUGH WILL AMPLIFY OVER FROM THE CENTRAL ATLANTIC INTO THE EASTERN
CARIBBEAN DURING THE WEEKEND. AT LOW LEVELS...A STRONG HIGH PRESSURE
WILL ESTABLISH NORTH OF THE LOCAL ISLANDS LATE THURSDAY...LEADING TO
AN INCREASE IN THE TRADE WIND FLOW.

&&

.DISCUSSION...A FAIRLY STRONG EASTERLY TRADES HAVE PUSHED CLOUDS AND
SHOWERS ACROSS THE FORECAST AREA TODAY. 12Z TJSJ SOUNDING SHOWED
THAT THE TRADE WIND INVERSION HEIGHT HAS INCREASED SINCE YESTERDAY...
RESULTING IN DEEPER MOISTURE ADVECTION ACROSS THE REGION EARLY
THIS MORNING. HOWEVER...CLOUDS AND SHOWERS HAVE BEEN LESS FREQUENT
SINCE MID-MORNING AS A DRIER AIRMASS MOVED ACROSS THE FORECAST AREA.
AS THE RIDGE ALOFT WILL CONTINUE TO ERODE OVER THE NEXT 24 HOURS...
THE TRADE WIND INVERSION WILL CONTINUE TO WEAKEN...INCREASING THE
CONVECTIVE INSTABILITY ACROSS THE ISLANDS THURSDAY AND POSSIBLY ON
FRIDAY. AS A RESULT... EXPECT BETTER POTENTIAL FOR SHOWER DEVELOPMENT
DURING OVERNIGHT AND EARLY MORNING HOURS. THEREAFTER...THE UPPER RIDGE
REESTABLISHES AND BUILDS ACROSS THE REGION ONCE AGAIN...INCREASING
THE TRADE WIND INVERSION OVER THE WEEKEND. FOR EARLY NEXT WEEK...THE
FORECAST IS STILL UNCERTAIN. MODELS DISAGREE ON THE LOCATION OF THE
UPPER LEVEL TROUGH/LOW. THE LOCATION OF THE TROUGH WILL DETERMINE
THE WEATHER FOR THE ISLANDS THE FIRST PART OF NEXT WEEK. SO WE WILL
CONTINUE TO MONITOR THE MODEL SOLUTIONS TO SEE HOW THIS PATTERN UNFOLDS.

&&

.AVIATION...VFR THRU 19/00Z BUT CLOUDS AND SHOWERS INCREASE AFTER
19/03Z WITH A CHANCE OF MVFR CIGS AT JSJ...USVI TERMINALS MAINLY
BETWEEN 03Z-12Z. SFC WINDS ALSO STRENGTHEN TOMORROW WITH EAST WINDS
15G25KT.

&&

.MARINE...SEAS 4-6 FT TODAY BUT EXPECTED TO BUILD 6-7 FT ON THURSDAY
AS TRADES STRENGTHEN. SEAS WILL DETERIORATE FURTHER OVER THE WEEKEND
AS WINDS STRENGTHEN FURTHER. SMALL CRAFT ADVISORY IS IN EFFECT FOR
THE OFFSHORE ATLANTIC WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 84 73 82 / 50 50 30 60
STT 75 86 75 85 / 50 50 20 40

[cycloneye]

Good morning. No change to the pattern of scattered showers moving thru PR and VI for the next few days.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
459 AM AST THU DEC 19 2013

.SYNOPSIS...RIDGE ALOFT WILL CONTINUE TO ERODE AS UPPER LEVEL TROUGH
ACROSS THE WESTERN ATLANTIC DEEPENS AND RELOCATES SOUTH TO EAST OF
THE LOCAL ISLANDS. SURFACE HIGH WILL CONTINUE TO BUILD ACROSS THE
WEST AND CENTRAL ATLANTIC...TIGHTENING THE LOCAL PRESSURE GRADIENT.

&&

.DISCUSSION...PARTLY CLOUDY SKIES PREVAILED ACROSS THE LOCAL ISLANDS
OVERNIGHT. ISOLATED TO LOCALLY SCATTERED FAST MOVING SHOWERS WERE
NOTED OVER THE USVI AS WELL AS THE NORTHEAST QUADRANT OF PUERTO RICO.
TEMPERATURES WERE MAINLY IN THE MID 70S IN COASTAL AREAS WITH TRADE
WINDS AROUND 10 MPH.

PATCHES OF MOISTURE EMBEDDED IN THE TRADES WILL CONTINUE TO MOVE ACROSS
THE LOCAL AREA FROM TIME TO TIME AND WILL COMBINE WITH DEEPENING UPPER
LEVEL TROUGH TO ENHANCE SHOWER ACTIVITY ACROSS THE LOCAL ISLANDS FRIDAY
AND SATURDAY. THESE SCATTERED TO LOCALLY NUMEROUS SHOWERS WILL BE FOCUSED
ACROSS NORTH AND EAST PUERTO RICO AS WELL AS PORTIONS OF THE USVI...
WITH A FEW ISOLATED SHOWERS POSSIBLE ELSEWHERE.

LATEST ECMWF AND GFS GUIDANCE SUGGESTED THAT SHOWER INTENSITY AND COVERAGE
WILL DECREASE SOMEWHAT SUNDAY AND PROBABLY MONDAY AS THE AFOREMENTIONED
TROUGH RELOCATES SOUTH TO EAST OF THE LOCAL ISLANDS WITH ITS CONVERGENT
SIDE OVER US. HOWEVER...BY DAY 05... MODELS CONTINUES TO DIVERGE ON
THE LOCATION AND EVOLUTION OF THIS FEATURE...THEREFORE NO CHANGES TO
MEDIUM RANGE FORECAST. SCATTERED TRADE WIND SHOWERS STILL INCLUDED
ACROSS THE WINDWARD SIDE OF LOCAL ISLANDS TUESDAY THROUGH AT LEAST
FRIDAY.

&&

.AVIATION...MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS THE FLYING
AREA...HOWEVER PASSING SHOWERS WILL CONTINUE THROUGH THE FCST PERIOD
WITH VCSH OVER TJSJ...TIST...TISX...TNCM AND TKPK. EASTERLY WIND
FLOW WILL CONTINUE AT 10 KT OR LESS DURING THE EARLY MORNING
HOURS...WITH SOME GUSTS NEAR SHOWERS. AFTER 19/12Z...EASTERLY LOW
LEVEL WINDS STRENGTHEN TO 10 TO 15 KTS GUSTING TO 25 KTS.

&&

.MARINE...SEAS OF UP TO 7 FEET TODAY BUT EXPECTED TO BUILD 7-9
FEET OVER THE WEEKEND AS WINDS STRENGTHEN FURTHER. SMALL CRAFT
ADVISORIES ARE IN EFFECT.

&&

.CLIMATE...2013 CURRENTLY RANKS AS THE 6TH AND 4TH WETTEST YEAR ON
RECORD AT LUIS MUNOZ MARIN INTL AIRPORT(TJSJ) AND CYRIL E. KING
AIRPORT(TIST) WITH 83.06" AND 53.61" RESPECTIVELY. THE WETTEST YEAR
ON RECORD WAS 2010...WITH 89.50" AND 61.36" AT TJSJ AND TIST
RESPECTIVELY.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
305 PM AST THU DEC 19 2013

.SYNOPSIS...A LONGWAVE TROUGH OVER THE NORTHWEST ATLANTIC WILL
AMPLIFY INTO A CUTOFF LOW DURING THE WEEKEND. AT LOW LEVELS...A
STRONG HIGH PRESSURE WILL ESTABLISH NORTH OF THE LOCAL ISLANDS
LATE TONIGHT...LEADING TO AN INCREASE IN THE TRADE WIND FLOW
THROUGH AT LEAST SUNDAY. CLOUD CLUSTERS EMBEDDED IN THE TRADES
WILL CONTINUE TO FAVOR LIGHT TO MODERATE SHOWERS ACROSS THE VIRGIN
ISLANDS...CULEBRA... VIEQUES AND EASTERN PUERTO RICO THROUGH THE
END OF THE WEEK.

&&

.DISCUSSION...BRISK EASTERLY TRADE WINDS HAVE CARRIED ISOLATED AREAS
OF CLOUDS AND SHOWERS ACROSS THE LOCAL ISLANDS TODAY. HOWEVER...IR
AND VISIBLE SATELLITE IMAGERY SHOWS AN AREA OF DRIER AIR BETWEEN THE
NORTHERN LEEWARD ISLANDS AND THE U.S. VIRGIN ISLANDS THAT IS EXPECTED
TO MOVE OVER THE LOCAL AREA TONIGHT AND OVERNIGHT. THIS WILL RESULT
IN MUCH LESS CLOUD AND SHOWER COVERAGE ACROSS THE ISLANDS OVERNIGHT.
ANOTHER GROUP OF CLOUDS AND SHOWERS FOLLOWED THIS DRIER SLOT AND
IS EXPECT TO BRING ANOTHER ROUND OF SCATTERED TO LOCALLY NUMEROUS
SHOWERS ON FRIDAY. THIS SHOWER ACTIVITY ON FRIDAY COULD BE HEAVY
AT TIMES UNDER THE INFLUENCE OF DEEPENING TROUGH ALOFT. MOST OF
THE ACTIVE WEATHER IS EXPECTED ON FRIDAY AS DEEPER MOISTURE POOLS
FROM THE NORTHEAST AND A UPPER DIVERGENT PATTERN PREVAILS ALOFT.
THEN...MOISTURE LEVELS WILL DECREASE AGAIN DURING THE WEEKEND
LIMITING THE SHOWER COVERAGE ACROSS THE ISLANDS. ONCE AGAIN THE
MODELS DISAGREE ON THE LOCATION OF THE UPPER LEVEL TROUGH/LOW FOR
EARLY/MID NEXT WEEK. THE LOCATION OF THE TROUGH WILL DETERMINE THE
WEATHER FOR THE ISLANDS DURING CHRISTMAS WEEK. AT THIS TIME...THE
FORECAST CONTINUES TO BE UNCERTAIN FOR NEXT WEEK...SO WE WILL
MONITOR HOW THIS PATTERN UNFOLDS.

&&

.AVIATION...VFR THRU 19/06Z BUT CLOUDS AND SHOWERS INCREASE AFTER
19/06Z WITH A CHANCE OF MVFR CIGS AT SJ...USVI TERMINALS MAINLY
BETWEEN 06Z-12Z. SFC WINDS ALSO STRENGTHEN TOMORROW WITH EAST WINDS
18G27KT.

&&

.MARINE...SMALL CRAFT ADVISORY ARE IN EFFECT FOR THE OFFSHORE
ATLANTIC WATERS. HOWEVER...THE SMALL CRAFT ADVISORY FOR THE REST
OF THE WATERS HAVE BEEN DELAYED UNTIL FRIDAY MORNING SINCE WINDS
NOT EXPECTED TO BE THAT STRONG TODAY. SMALL CRAFT APPEARS DEFINITE
FRI-SUN WITH WINDS NEAR 20 KT AND SEAS 7-9 FT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 82 73 81 / 30 60 50 50
STT 76 85 75 85 / 20 40 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1002 PM AST THU DEC 19 2013

.UPDATE...ISOLATED TO SCATTERED SHOWERS HAVE BEEN AFFECTING THE
NORTHERN HALF OF PUERTO RICO TONIGHT. THESE SHOWERS HAVE BEEN
MOVING QUICKLY WESTWARD. A PATCH OF MOISTURE WILL MOVE ACROSS THE
AREA TOMORROW MORNING...WHICH WILL INCREASE THE CLOUDINESS AND
SHOWERS ACTIVITY ACROSS THE AREA. FORECAST IS ON TRACK WITH
ONGOING WEATHER SITUATION...THEREFORE..NO CHANGES TO FORECAST
GRIDS NEEDED TONIGHT.

&&

.AVIATION...MOSTLY VFR ...WITH SOME VCSH...THRU THE PERIOD WITH A
BETTER CHANCE FOR BRIEF PDS OF MVFR CIGS THRU 20/12Z AT TJSJ AND
USVI TERMINALS. SFC WINDS ALSO STRENGTHEN ON FRIDAY WITH EAST WINDS
18G27KT.

&&

.MARINE...STILL EXPECT SEAS TO INCREASE UP TO 9 FEET TOMORROW.
SMALL CRAFT ADVISORIES ARE IN EFFECT.

[cycloneye]

Good morning. Scattered showers will move thru PR and VI today thru Saturday.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
421 AM AST FRI DEC 20 2013

.SYNOPSIS...UPPER LEVEL TROUGH ACROSS THE WEST AND CENTRAL
ATLANTIC WILL CONTINUE TO DEEPEN THROUGH THE DAY...WITH ITS
AXIS RELOCATING SOUTH TO EAST OF THE LOCAL ISLANDS BY THE END
OF THE UPCOMING WEEKEND. SURFACE HIGH WILL CONTINUE TO AMPLIFY
ACROSS THE CENTRAL ATLANTIC...PROMOTING A FRESH TO LOCALLY
STRONG NORTHEAST WIND FLOW OVER THE AREA.

&&

.DISCUSSION...AS EXPECTED CLEAR TO PARTLY CLOUDY SKIES PREVAILED
ACROSS THE LOCAL ISLANDS OVERNIGHT...WITH A FEW ISOLATED FAST
MOVING SHOWERS OVER THE USVI AS WELL AS THE NORTHEAST QUADRANT
OF PUERTO RICO. TEMPERATURES WERE MAINLY IN THE LOW 80S IN COASTAL
AREAS WITH TRADE WINDS OF UP TO 20 MPH.

PATCHES OF MOISTURE EMBEDDED IN THE TRADES WILL CONTINUE TO MOVE
ACROSS THE LOCAL AREA FROM TIME TO TIME AND WILL COMBINE WITH
DEEPENING UPPER LEVEL TROUGH TO ENHANCE SHOWER ACTIVITY ACROSS
THE LOCAL ISLANDS TODAY AND SATURDAY. THESE SCATTERED TO LOCALLY
NUMEROUS SHOWERS WILL BE FOCUSED MAINLY ACROSS NORTH AND EAST
PUERTO RICO AS WELL AS THE USVI...WITH A FEW ISOLATED SHOWERS
ELSEWHERE. IN FACT...SATELLITE IMAGERY SHOWED AN APPROACHING AREA
OF CLOUDINESS AND SHOWERS WHICH IS EXPECTED TO REACH THE LOCAL
ISLANDS EARLY THIS MORNING AND STAY WITH US THROUGH THE DAY.

LATEST ECMWF AND GFS GUIDANCE SUGGESTED THAT SHOWER INTENSITY AND
COVERAGE WILL DECREASE SOMEWHAT SATURDAY NIGHT AND SUNDAY AS THE
AFOREMENTIONED TROUGH RELOCATES SOUTH TO EAST OF THE LOCAL ISLANDS
WITH ITS CONVERGENT SIDE OVER US. HOWEVER...LIGHT PASSING SHOWERS
EMBEDDED IN THE TRADES CANT BE RULED OUT.

FOR THE NEXT WORK WEEK MODELS CONTINUE TO DIVERGE ON THE EXACT
LOCATION AND EVOLUTION OF THE UPPER LEVEL TROUGH...THEREFORE NO
CHANGES TO MEDIUM RANGE FORECAST. SCATTERED TRADE WIND SHOWERS
STILL INCLUDED ACROSS THE WINDWARD SIDE OF LOCAL ISLANDS FOLLOWING
LOCAL CLIMATOLOGY.

&&

.AVIATION...MOSTLY VFR CONDITIONS WITH VCSH WILL PERSIST THRU THE
FCST PERIOD. PERIODS OF BRIEF SHRA AND MVFR CIGS THRU 20/20Z
EXPECTED OVER TJSJ AND USVI TERMINALS. EAST NORTHEAST SFC WINDS
AT 15 TO 20 KTS WITH HIGHER GUSTS.

&&

.MARINE...WINDS WILL CONTINUE TO STRENGTHEN THROUGH EARLY SUNDAY
WITH WINDS NEAR 20 KNOTS TODAY AND SEAS BUILDING 6 TO 9 FEET
MAINLY OVER THE OFFSHORE WATERS. SMALL CRAFT ADVISORIES ARE NOW IN
EFFECT FOR MOST OF THE COASTAL WATERS.

&&

.CLIMATE...THIS YEAR THE WINTER SOLSTICE WILL OCCUR ON DECEMBER
21ST AT 1:11 PM AST. THIS DAY MARKS THE SHORTEST DAY AND THE
LONGEST NIGHT OF THE YEAR. IN THE NORTHERN HEMISPHERE...IT OCCURS
WHEN THE SUN IS DIRECTLY OVER THE TROPIC OF CAPRICORN.

STATISTICALLY...2013 CURRENTLY RANKS AS THE 6TH AND 4TH WETTEST YEAR
ON RECORD AT THE LUIS MUNOZ MARIN INTL AIRPORT(TJSJ) AND THE CYRIL
E. KING AIRPORT(TIST) WITH 83.28" AND 53.88" RESPECTIVELY. THE
WETTEST YEAR ON RECORD WAS 2010 WITH 89.50" AND 61.36" AT TJSJ AND
TIST RESPECTIVELY.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
257 PM AST FRI DEC 20 2013

.SYNOPSIS...UPPER LEVEL TROUGH ACROSS THE CNTRL ATLC WILL AMPLIFY
SOUTHWESTARD TO THE ERN CARIBBEAN AND SAMERICA WITH A CLOSED LOW
FORECAST TO DEVELOP NEAR 22N AND 60W BY TUE MORNING.

&&

.DISCUSSION...UPPER LEVEL CONVERGENCE ON THE BACKSIDE OF UPPER
LEVEL TROUGH AXIS WILL RESULT IN DRYING TONIGHT BUT SHOWERS RETURN
AGAIN TOMORROW AS SFC WINDS STRENGTHEN SOME MORE. THE PATTERN WILL
REPEAT ITSELF AGAIN ON SUN.

SUN NIGHT ON...DEEPENING MID-UPPER LEVEL TROUGH ACROSS THE CNTRL
ATLC INTO THE ERN CARIBBEAN WILL RESULT IN SUBSTANTIAL MID-LEVEL
COOLING AND STEEPENING LOW-MID LEVEL LAPSE RATES WHICH ARE FCST TO
BE NEAR THE 75TH PERCENTILE FOR THIS TIME OF YEAR. THIS WILL
CREATE UNSTABLE CONDITIONS WITH AN ENHANCED RISK OF SHOWERS AND
EVEN THUNDERSTORMS. ATTM...GFS/GEFS KEEP TROUGH AXIS AND BEST
MOISTURE OVER THE LEEWARDS SO THE POTENTIAL FOR FLOODING RAINS
OVER PR REMAINS LOW AT THIS TIME BUT WILL NEED TO BE MONITORED IN
SUBSEQUENT SHIFTS IF CUTOFF LOW MOVES AS FAR SOUTH AND WEST AS THE
00Z ECMWF IS SHOWING. WEATHER WILL BEGIN TO IMPROVE LATE NEXT
WEEK AS TROUGH WEAKENS AND BEGINS TO PULL OUT TO THE NORTHEAST.

&&

.AVIATION...MOSTLY VFR CONDITIONS WITH VCSH WILL PERSIST THRU THE
FCST PERIOD. NE WINDS OF 15-30 KT EXPECTED BELOW FL100 THROUGH SAT
MORNING.


&&

.MARINE...SFC WINDS WILL STRENGTHEN SOME MORE AND PEAK SUN WITH
SEAS BUILDING 6-8 FT. WINDS AND SEAS WILL BEGIN TO DIMINISH MON.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 83 75 83 / 50 50 20 20
STT 76 85 76 85 / 20 20 20 30

[cycloneye]

Good morning. Scattered showers will continue to move thru PR and VI today and Sunday.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
538 AM AST SAT DEC 21 2013

.SYNOPSIS...AT UPPER LEVELS...A TROUGH WILL MOVE THROUGH THE AREA
FROM THE NORTH THIS AFTERNOON. THEN THROUGH CHRISTMAS EVE AN UPPER
LEVEL LOW WILL COME FROM THE EAST NORTHEAST TO WITHIN ABOUT 300
MILES OF SAINT THOMAS BEFORE RETREATING AND DISSIPATING DURING THE
REMAINDER OF THE WEEK. A HIGH PRESSURE WILL RIDGE IN FROM THE
SOUTH LATE NEXT WEEKEND ALONG WITH A JET FROM THE NORTHWEST.

AT MID LEVELS...HIGH PRESSURE OVER THE NORTHERN BAHAMAS WILL MOVE
INTO THE CENTRAL ATLANTIC BY MID WEEK...BUT ANOTHER HIGH WILL FORM
OVER CUBA DURING THAT TIME. LOW PRESSURE IN THE SOUTHERN MID
LATITUDES OF THE CENTRAL ATLANTIC WILL REFORM JUST EAST OF THE
WINDWARD ISLANDS EARLY NEXT WEEK AS A REFLECTION OF THE STRONG UPPER
LEVEL LOW...AND WILL MOVE TO JUST NORTH OF THE LEEWARD ISLANDS BY
MID WEEK. DURING THE REMAINDER OF THE WEEK AND INTO THE NEXT
WEEKEND IT WILL WEAKEN AND DRIFT INTO THE WESTERN TROPICAL
ATLANTIC.

AT LOWER LEVELS...STRONG HIGH PRESSURE NORTH OF THE AREA WILL
DRIFT INTO THE CENTRAL ATLANTIC BY WEDNESDAY AS A WEAK TROUGH
REFLECTION FORMS OVER THE ANEGADA PASSAGE. THIS TROUGH WILL DRIFT
ACROSS THE AREA DURING THE REMAINDER OF THE WORK WEEK AND TRADE
WINDS WILL CONTINUE. ALTHOUGH MOISTURE LEVELS ARE RELATIVELY LOW
DURING THE MIDDLE OF THE WEEK...MOISTURE INCREASES DRAMATICALLY AS
MOISTURE IS BROUGHT UP BEHIND THE TROUGH GENERATED BY THE MID AND
UPPER LOW.

&&

.DISCUSSION...SATELLITE IMAGERY SHOWS PATCHES OF MOISTURE MOVING
IN FROM THE CENTRAL ATLANTIC AND RADAR CONFIRMS THE SHOWERY NATURE
OF THE AIR MASS. THE GFS ALSO SHOWS AN INCREASE IN RELATIVE
HUMIDITY AT 850 MB AND A SHARP INCREASE IN PRECIPITABLE WATER
THIS AFTERNOON...MAKING SHOWERS IN THE ONSHORE EAST NORTHEAST LOW-
LEVEL FLOW LIKELY. SHOWERS WILL TAPER OFF TOWARD THE WEST BUT SOME
CONVERGENCE TOWARD THE EXTREME WEST END OF PUERTO RICO WILL
INCREASE THE LIKELIHOOD OF A SHOWER THERE AND IN THE MONA PASSAGE.
THIS PATTERN LOOKS VERY PERSISTENT...BUT MOISTURE DIMINISHES LATE
MONDAY THROUGH EARLY CHRISTMAS DAY...AND SHOULD ALLOW IMPROVING
CONDITIONS FOR TUESDAY AND WEDNESDAY. THEN THE MIMIC PRODUCT SHOWS
AN APEX OR INVERTED V OF MOISTURE...NOW NEAR 38 WEST IN THE
WESTERN TROPICAL ATLANTIC...MOVING INTO THE LEEWARD ISLANDS BY
FRIDAY AND INTERACTING WITH THE SURFACE TROUGH ALREADY GENERATED
BY THE TUTT LOW TO THE EAST NORTHEAST OF THE AREA. WHILE THE
ECMWF HAS THIS LOW MOVING OVER PUERTO RICO...PREFER THE MORE
MODERATE SOLUTION OF THE GFS WHICH HOLDS IT...AS VIGOROUS AS IT
IS...EAST NORTHEAST OF THE AREA BY ABOUT 300 MILES. THIS WOULD
ALSO MODERATE THE FORMATION OF THE SURFACE TROUGH...WHICH WILL BE
IN PART RESPONSIBLE FOR THE DRIER AIR AHEAD OF IT ON TUESDAY AND
WEDNESDAY...BEFORE WEAKENING AND MOVING WEST WITH THE TRADE WIND
FLOW THURSDAY AND FRIDAY. AS IT MOVES WEST THE SOUTHEAST FLOW OVER
THE AREA SHOULD PICK UP THE MOISTURE FROM THE MOIST TROUGH MOVING
ACROSS THE TROPICAL ATLANTIC AND INCREASE SHOWER ACTIVITY ON
FRIDAY.

TEMPERATURES HAVE BEEN TOO LOW IN THE GFS AND MEX FORECAST MOS AND
HAVE RAISED THEM TO WHAT HAS BEEN OCCURRING DURING THE LAST WEEK
ACROSS THE ENTIRE 7 DAY FORECAST. STRONG BREEZES AND WARM WATERS
WILL KEEP TEMPERATURES IN THE MID 80S IN THE LOWER ELEVATION
WINDWARD AREAS OF PUERTO RICO AND ALSO THE WARMER AREAS OF THE
U.S. VIRGIN ISLANDS. SHOWERS MAY COOL MAX TEMPS THIS
AFTERNOON...SO EXPECT MOST HIGHS AROUND OR JUST BEFORE NOON WHERE
SHOWERS OCCUR.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED ACROSS THE FLYING AREA
WITH VCSH AROUND TJSJ...TJBQ AND THE USVI TERMINALS. BRIEF MVFR
CIGS CAN BE EXPECTED WITH SOME OF THE PASSING SHOWERS. EAST
NORTHEAST WINDS AT 15-25 KT BELOW FL100.

&&

.MARINE...WINDS OF 17 TO 23 KNOTS ACROSS THE LOCAL WATERS ARE
KEEPING SEAS HAZARDOUS WITH LOCALLY GENERATED WIND WAVES AND SOME
SWELL GENERATED FARTHER OUT IN THE SAME FETCH. HENCE PERIODS OF 7
AND 10 SECONDS WILL BE DOMINATE. WINDS AND SEAS DO NOT BEGIN TO
MODERATE UNTIL TUESDAY IN ALL BUT THE MORE PROTECTED AREAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 76 83 76 / 60 50 60 50
STT 85 78 84 77 / 50 50 50 50

[cycloneye]

Forecast for Antigua and Barbuda:

Cldy

Synopsis: High pressure ridge will continue to generate a brisk trade wind flow, as well as transport shallow pockets of low level moisture across the islands at times during the next 24 hours.

Wx: Partly sunny skies today and fair to partly cloudy skies tonight with a few quick passing showers, mainly overnight.

Winds: ENE at 14-22kts over land, increasing to 26kts over open waters..

Seas: Rough, swells 2.1-2.8m or 7-9ft. A warning remains in place for small craft operators and sea bathers against rough sea conditions.

http://www.antiguamet.com/Antigua_Met_f ... opsis.html

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
242 PM AST SAT DEC 21 2013

.SYNOPSIS...
STRONG MID/UPPER LEVEL RIDGE JUST WEST OF THE AREA...WILL HELP
MAINTAIN TRADE WIND CAP INVERSION ACROSS THE REGION OVER THE NEXT
FEW DAYS. TUTT EXTENDS SOUTHWEST ACROSS THE NORTHERN LEEWARDS INTO
THE EASTERN CARIBBEAN. THE TUTT IS TO BECOME AMPLIFIED AND DEEPEN
OVER THE NEXT FEW DAY...AS A TUTT LOW IS FORECAST TO FORM JUST
NORTHEAST OF THE NORTHERN LEEWARDS BY MONDAY THEN SINK FURTHER
SOUTHWEST INTO THE EASTERN CARIBBEAN. IN THE MEANTIME...BROAD AND
DOMINANT SURFACE HIGH PRESSURE RIDGE ACROSS THE ATLANTIC WILL
MAINTAIN A TIGHT PRESSURE GRADIENT ACROSS THE REGION AND A PERSISTENT
NORTHEASTERLY TRADE WIND FLOW THOUGH AT LEAST MONDAY OF NEXT WEEK.
THEREAFTER THE PRESSURE GRADIENT WILL BEGIN TO LOOSEN IN ADVANCE
OF A TUTT INDUCED SURFACE TROUGH WHICH WILL APPROACH FROM THE
EAST.

&&

.DISCUSSION...THE PREVAILING BRISK NORTHEASTERLY WIND FLOW WILL
MAINTAIN THE COOL AND FAIRLY MOIST LOW LOW TO MID LEVEL ADVECTIVE
PATTERN ACROSS THE REGION THROUGH THE REST OF THE WEEKEND AND INTO
THE EARLY NEXT WEEK. THIS WILL RESULT IN PERIODS OF QUICK PASSING
LOW TO MID LEVEL CLOUDINESS WITH INTERVALS OF MOSTLY ISOLATED TO
SCATTERED SHOWERS ACROSS THE REGION. MOST OF THE CLOUDINESS
HOWEVER SHOULD BE FOCUSED ACROSS THE NORTH AND NORTHEASTERN
PORTIONS OF PUERTO RICO AS WELL AS OVER PARTS OF MAINLY THE
NORTHERN VIRGIN ISLANDS...AS ACTIVITY WILL BE STEERED MAINLY BY
THE PREVAILING NORTHEASTERLIES. A GRADUAL CLEARING OF LOW TO MID
LEVEL CLOUDINESS AND DECREASING SHOWERS CAN BE EXPECTED TO OCCUR
EACH DAY DURING THE LATE MORNING AND INTO THE AFTERNOON HOURS. NO
SIGNIFICANT RAINFALL ACCUMULATIONS IS EXPECTED ACROSS THE REGION
OVER THE REST OF THE WEEKEND. HOWEVER... THE PERSISTENT EARLY
MORNING TRADE WIND SHOWERS WILL MAINTAIN AND OVERALL MOIST PATTERN
WITH SATURATED SOILS ACROSS MUCH OF THE NORTHERN AND THE EAST
SECTIONS OF PUERTO RICO. FOR THIS REASON DURING THE NEXT FEW
DAYS...RESIDENTS AND MOTORISTS SHOULD REMAIN ALERT TO POSSIBLE
MUDSLIDES IN AREAS OF STEEP TERRAIN...EVEN AFTER THE RAINS HAVE
ENDED.

BY THE LATTER PART OF THE WEEK...APPROACHING TUTT LOW AND INDUCED SURFACE
TROUGH WILL MODIFY PREVAILING WIND FLOW WITH WINDS TO BECOME MORE
EAST TO SOUTHEAST ON THURSDAY AND FRIDAY. BY THEN EXPECT OCCASIONAL
BURSTS OF TUTT ENHANCED TROPICAL MOISTURE TO BE ADVECTED ACROSS THE
REGION FROM TIME TO TIME AT LEAST THROUGH SATURDAY. A GRADUAL IMPROVEMENT
IS EXPECTED BY LATE SUNDAY AS THE SURFACE HIGH PRESSURE ONCE AGAIN
REESTABLISHES NORTH OF THE REGION AND THE PREVAILING NORTHERLY WIND
FLOW RETURNS.

&&

.AVIATION...ISOLD MVFR NEXT 24 HOURS IN ISOLD/SCT SHRA XCP TJPS WI
ISOLD OBSCD MTNS. FL010-FL150 WINDS THRU SUNDAY ENE 20-30 KT.

&&

.MARINE...LATEST DATA FROM THE SURROUNDNG BUOYS AND ALSO SOME PREVIOUS
SHIP OBSERVATIONS CONTINUED TO CONFIRM WIND GENERATED SEAS REMAIN HIGH
DUE TO FRESH TO LOCALLY STRONG NORTHEAST TRADE WINDS. SMALL CRAFT ADVISORIES
THEREFORE REMAIN IN EFFECT FOR MOST OF THE LOCAL WATERS. PLEASE REFER
TO THE LATEST COASTAL WATERS FORECAST AND MARINE WEATHER MESSAGE PRODUCTS
ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN PR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 82 72 81 / 60 60 50 60
STT 75 85 75 85 / 60 60 50 60

[cycloneye]

Good morning. It looks like Chtistmas will be a wet one as a trough gets stronger bringing numerous showers not only to PR and VI but to all the islands in the NE Caribbean.

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
539 AM AST SUN DEC 22 2013

.SYNOPSIS...AT UPPER LEVELS...THE TROUGH OVER THE LOCAL AREA WILL
REMAIN JUST SOUTH OF PUERTO RICO AND SAINT CROIX. A LOW PRESSURE
WILL FORM ABOUT 850 MILES NORTHEAST OF SAINT CROIX LATE SUNDAY AND
MOVE OVER PUERTO RICO BY TUESDAY. THEN IT WILL WEAKEN DURING THE
REST OF THE WEEK. HIGH PRESSURE OVER THE SOUTHWEST CARIBBEAN WILL
MOVE OVER THE AREA OVER THE WEEKEND.

AT MID LEVELS...HIGH PRESSURE JUST NORTH OF THE BAHAMAS WILL MOVE
INTO THE CENTRAL ATLANTIC BY MID WEEK. LOW PRESSURE 1150 MILES
EAST NORTHEAST OF PUERTO RICO WILL MOVE SOUTH OF THE PASSING HIGH
ON MONDAY AND SETTLE OVER AND SOUTHWEST OF THE AREA TUESDAY
THROUGH WEDNESDAY...WHERE IT WILL WEAKEN DURING THE REST OF THE
WEEK. HIGH PRESSURE OVER THE CENTRAL ATLANTIC THEN RETURNS TO
COVER MUCH OF THE AREA FROM THE WESTERN CARIBBEAN AND PUERTO RICO
AND THE ATLANTIC OCEAN TO THE EAST NORTHEAST.

AT LOWER LEVELS...HIGH PRESSURE NORTH OF THE AREA WEAKENS SLIGHTLY
AND MOVES INTO THE CENTRAL ATLANTIC BY MID WEEK. A TROUGH FORMS
OVER THE AREA ON TUESDAY IN RESPONSE TO THE UPPER LEVEL LOW AND
MOVES WEST TO HAITI BY WEDNESDAY NIGHT...PULLING MOISTURE AND
WARMER AIR IN FROM THE TROPICAL ATLANTIC. TRADE WINDS THEN CONTINUE
THROUGH AT LEAST THE BEGINNING OF THE FOLLOWING WEEK.

&&

.DISCUSSION...AREAS OF MOISTURE OVER A WARM OCEAN CONTINUE TO
SUPPORT SHOWERY ACTIVITY IN THE EAST NORTHEAST FLOW. THIS HAS
BROUGHT MEASURABLE RAIN OVERNIGHT TO MOST OF PUERTO RICO AND THE
U.S. VIRGIN ISLANDS NORTHEAST OF A LINE FROM AGUADA TO
ARROYO...INCLUDING THE CARIBBEAN WATERS BETWEEN PUERTO RICO AND
SAINT CROIX AND WEST SOUTHWEST OF THERE AND MOST OF THE ATLANTIC
WATERS. THESE SHOWERS ARE EXPECTED TO CONTINUE INTERMITTENTLY
THROUGH TUESDAY...WITH VERY GOOD CHANCES FOR RAIN ON MONDAY OVER
THE WINDWARD HALF OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS. OVER
THE LAST 24 HOURS THE GFS BROUGHT ITS SOLUTION IN LINE WITH THE
ECMWF WITH THE UPPER LEVEL LOW MOVING OUT OF THE SUB TROPICAL
ATLANTIC AND OVER THE LOCAL AREA BY TUESDAY. THIS POWERS UP A LOW
LEVEL TROUGH AT THE SURFACE THAT MOVES INTO THE AREA MONDAY NIGHT
AND TUESDAY...DEEPENING OVER THE MONA CHANNEL ON TUESDAY. THAT
STRENGTHENING WILL THEN BRING BETTER TROPICAL MOISTURE OUT OF THE
SOUTHEAST IN SOUTHEAST FLOW THAT WILL GREATLY INCREASE THE CHANCES
FOR RAIN ON CHRISTMAS FOR SOUTHEAST PUERTO RICO AND THE U.S.
VIRGIN ISLANDS. HAVE NOT INCREASED THE POPS FOR SAN JUAN MUCH DUE
TO THE SOUTHEAST FLOW...BUT SHOWERS COULD BE MORE PREVALENT IF
MOISTURE PREVAILS. THE GFS AND THE ECMWF SHOW ABOUT A 15 METER
INCREASE IN 1000-850 MB THICKNESS THAT WILL END THE SHORT COOLING
SEEN ON MONDAY...BUT HIGH TEMPERATURES SHOULD NOT VARY MORE THAN A
FEW DEGREES AS WARMING TAKES HOLD. DRIER AIR MOVES IN ON THURSDAY
MORNING...BUT BANDS OF MOISTURE FOLLOW...KEEPING AT LEAST
SCATTERED SHOWERS IN THE FORECAST FOR EASTERN PUERTO RICO AND THE
U.S. VIRGIN ISLANDS AND AT LEAST ISOLATED SHOWERS FOR WESTERN
PUERTO RICO THROUGH THE END OF THE YEAR. TRADE WIND FLOW DECREASES
ON TUESDAY AS THE TROUGH FORMS AND ALTHOUGH THE WINDS RETURN TO AN
EASTERLY FLOW BY SATURDAY...WIND SPEEDS WILL BE LESS THAN THEY
HAVE BEEN THIS WEEKEND.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDITIONS ARE EXPECTED ACROSS
THE LOCAL FLYING AREA FOR THE NEXT 24 HOURS IN SCATTERED SHRA WITH
MOSTLY OBSCURED MTNS. EAST NORTHEAST WINDS AT 15-30 KT FM SFC UP TO
20 KFT.

&&

.MARINE...WINDS WILL INCREASE SLIGHTLY TODAY BEFORE DIMINISHING
LATER MONDAY AND TUESDAY. THIS WILL KEEP SMALL CRAFT CONDITIONS
ACROSS ALL BUT AMZ745 NEAR SHORE WEST OF MAYAGUEZ THROUGH AT LEAST
MONDAY. WINDS AND SEAS DIMINISH TUESDAY AND WEDNESDAY AS TROUGHING
MOVES THROUGH. MODELS ARE RUNNING A BIT HIGH...BUT AM FAIRLY
CONFIDENT THAT SMALL CRAFT ADVISORIES SHOULD BE DOWN EVERYWHERE BY
LATE WEDNESDAY OR THURSDAY AT THE LATEST.

&&

.HYDROLOGY...WITH THE CONTINUOUS FLOW OF MOISTURE...MUCH OF THE
SOILS IN NORTHEAST PUERTO RICO ARE BECOMING SATURATED. THIS IS
EXPECTED TO INCREASE THE RISK OF SOME SAGGING OR EVEN MUDSLIDES IN
STEEPER TERRAIN AS THE WET WEEK CONTINUES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 75 83 75 / 80 60 80 80
STT 85 77 86 76 / 80 60 90 90

[Macrocane]

Observations from the 5th cold surge of the season in Central America have been updated: http://www.storm2k.org/phpbb2/viewtopic.php?f=22&t=106879&p=2363027#p2363027

[cycloneye]

Good afternoon. Yes to the above scenario for the NE Caribbean as a big trough will move thru the islands this week so stay tuned for more information.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
206 PM AST SUN DEC 22 2013

.SYNOPSIS...IN THE UPPER LEVELS...PERSISTENT MID TO UPPER LEVEL
HIGH PRESSURE RIDGE REMAIN ANCHORED ACROSS THE WEST AND SOUTHWESTERN
ATLANTIC...WHILE BROAD ELONGATED TROUGH/TUTT AXIS EXTENDS FROM THE
TROPICAL ATLANTIC WEST SOUTHWEST ACROSS THE NORTHERN LEEWARD
ISLANDS...THEN INTO THE EASTERN CARIBBEAN JUST SOUTH OF PUERTO
RICO. THIS PATTERN HAS MAINTAINED A FAIRLY STRONG SUBSIDENCE CAP
ACROSS THE REGION AND WILL CONTINUE TO DO SO AT LEAST UNTIL EARLY
MONDAY. THEREAFTER A DEVELOPING CUTOFF LOW AND THE AMPLIFYING
TROUGH WILL SHIFT WESTWARD ACROSS THE NORTHEASTERN CARIBBEAN WITH
THE CUTOFF LOW RELOCATING OVER OR NEAR PUERTO RICO BY LATE MONDAY
INTO EARLY TUESDAY. IN THE LOW LEVELS...BROAD AND DOMINANT AREA OF
HIGH PRESSURE SPREAD ACROSS THE ATLANTIC WILL MAINTAIN ITS HOLD
ACROSS THE REGION THROUGH AT LEAST TUESDAY...BUT WILL THEN WEAKEN
BY MID WEEK IN RESPONSE TO AN INDUCED SURFACE TROUGH APPROACHING
THE REGION FROM THE EAST AND A COLD FRONT EXITING THE EASTERN
SEABOARD OF THE UNITED STATES AND ENTERING THE WESTERN ATLANTIC.

&&

.DISCUSSION...THE PREVAILING NORTHEASTERLY WIND FLOW WILL MAINTAIN
THE COOL AND MOIST LOW LEVEL ADVECTIVE PATTERN ACROSS THE REGION
FOR THE NEXT FEW DAYS. THEREFORE PERIODS OF QUICK PASSING LOW TO
MID LEVEL CLOUDINESS WITH INTERVALS OF LIGHT TO MODERATE SHOWERS
WILL CONTINUE TO AFFECT THE ISLANDS AND LOCAL WATERS. LATEST 22/12Z
TJSJ UPPER AIR SOUNDING AS WELL AS THE BLENDED TOTAL PRECIPITABLE
WATER PRODUCT BOTH SUGGEST PWAT VALUES WERE BETWEEN 1.0 AND 1.40
INCHES. HOWEVER...THE PERSISTENT NORTHEASTERLIES WILL CONTINUE TO
BRING SURGES OF ADDITIONAL LOW LEVEL MOISTURE ACROSS THE REGION
FROM TIME TO TIME. THE STRONG CAP INVERSION WILL REMAIN IN PLACE
AT AROUND 700 MILLIBARS ALONG WITH GOOD UPPER LEVEL SUBSIDENCE.
THEREFORE THE OVERALL SHOWER ACTIVITY WILL BE SHALLOW AND FAST
MOVING. EXPECT LITTLE CHANGE IN THE WEATHER PATTERN THROUGH
TUESDAY. RECENT ASCAT RUNS AND DOPPLER WEATHER RADAR VELOCITY
PRODUCT CONTINUE TO SUGGEST STRONG TRADE WINDS BETWEEN 20-25 KT
WITH HIGHER GUSTS ACCOMPANYNG THE PASSING SHOWERS. STILL EXPECT
THE NORTHEAST TRADE WINDS TO BEGIN TO DIMINISH LATE MONDAY INTO
TUESDAY IN RESPONSE TO THE LOOSENING OF THE SURFACE PRESSURE
GRADIENT AS PREVIOUSLY MENTIONED.
BY THE MIDDLE OF THE WEEK... THE APPROACHING SURFACE TROUGH INDUCED
BY THE AFOREMENTIONED TUTT LOW WILL MOVE ACROSS AND BECOME AMPLIFIED
WHILE LIFTING WEST AND NORTH OVER THE FORECAST AREA DURING THE REST
OF THE WEEK. THIS SCENARIO WILL WEAKEN THE SURFACE PRESSURE GRADIENT...
AND LEAD TO LIGHT TO MODERATE SOUTHEASTERLY WINDS ACROSS THE REGION.
THE SURFACE/LOW LEVEL TROUGH WILL ALLOW DEEP TROPICAL MOISTURE ADVECTION
ACROSS THE AREA. AS A RESULT...EXPECT AN OVERALL WET WEATHER PATTERN
THROUGH MUCH OF THE WEEK...AS INTERVALS OF PASSING SHOWERS WILL CONTINUE
TO AFFECT THE ISLANDS AND SURROUNDING WATERS. SOME OF THE RAINFALL WILL
BE LOCALLY HEAVY AT TIMES AND BY THEN MORE LOCALIZED RAINFALL ACCUMULATION
WILL BE POSSIBLE DUE TO THE DIMINISHING TRADE WINDS.

ON ANOTHER NOTE...THE PERSISTENT LATE EVENING AND EARLY MORNING TRADE
WIND SHOWERS WILL MAINTAIN AND OVERALL MOIST PATTERN WITH SATURATED
SOILS ACROSS MUCH OF THE NORTHERN AND THE EAST SECTIONS OF PUERTO RICO.
FOR THIS REASON DURING THE NEXT FEW DAYS...RESIDENTS AND MOTORISTS SHOULD
REMAIN ALERT TO POSSIBLE MUDSLIDES IN AREAS OF STEEP TERRAIN...EVEN
AFTER THE RAINS HAVE ENDED.

&&

.AVIATION...CLUSTERS OF SHRA CURRENTLY MOVG THRU REGION BUT MOST DO
NOT REDUCE CONDS FM VFR. SEVERAL LARGE CLUSTERS AT NORTHERN LEEWARDS
MAY MORE OFTEN DO SO...FOR TNCM/TKPK NEXT AVRIL HRS AND PSBL AT TISX
BY 20Z. OTHW SCT/NMRS SHRA BUT ISOLD MVFR ACROSS AREA WI AREAS OF
OBSCD MTNS. WINDS FL010- FL200 ENE 20-30 KT WILL BEGIN TO WEAKEN AND
TURN ESE LATE MON/MON NITE.

&&

.MARINE...WINDS OF UP TO 23 KNOTS CONTINUED TODAY ACROSS THE
REGIONAL WATERS TO MAINTAIN ROUGH WIND GENERATED SEAS UP TO 8
FEET. CONDITIONS WILL BEGIN TO GRADUALLY IMPROVE AS WINDS SLOWLY
DECREASE ON MONDAY AND TUESDAY. IN THE MEANTIME SMALL CRAFT ADVISORIES
REMAIN IN EFFECT FOR MOST OF THE LOCAL WATERS. PLEASE REFER TO THE
LATEST COASTAL WATERS FORECAST AND MARINE WEATHER MESSAGE ISSUED
BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN OFFICE.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 82 70 81 / 60 80 80 80
STT 73 82 71 82 / 60 90 90 90

[cycloneye]

Here is the GFS model for Christmas day and is rather wet for most of the islands.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
928 PM AST SUN DEC 22 2013

.UPDATE....NO MAJOR CHANGES TO SHORT TERM GRIDS...FORECAST ON
TRACK. CUTOFF LOW WILL DEVELOP NORTHEAST OF THE LOCAL ISLANDS
AS UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC CONTINUES TO
DIG INTO THE EASTERN CARIBBEAN. THIS FEATURE WILL INDUCE A SURFACE
TROUGH THAT ALLOW DEEP MOISTURE TO POOL ACROSS THE AREA. AS A
RESULT...CONTINUE TO EXPECT A FEW PASSING SHOWERS FROM TIME TO
TIME TONIGHT AND MONDAY...BECOMING WETTER TUESDAY AND BEYOND.

[cycloneye]

Good morning. No change to the rainy scenario for Christmas day in the NE Caribbean.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
523 AM AST MON DEC 23 2013

.SYNOPSIS...UPPER LEVEL TROUGH FEW HUNDRED MILES NORTHEAST OF THE
LOCAL AREA WILL MOVE SOUTHWEST AND WILL APPROACH THE REGION
TUESDAY...LINGERING THROUGH AT LEAST THURSDAY. AT THE SURFACE...
LOW LEVEL TROUGH WILL MOVE ACROSS THE REGION TUESDAY INTO
WEDNESDAY.

&&

.DISCUSSION...SHOWERS HAVE BEEN INCREASING EARLY THIS MORNING
OVER THE COASTAL WATERS AND ACROSS THE LOCAL ISLANDS IN RESPOND TO
AN UPPER LEVEL TROUGH WHICH WILL APPROACH THE LOCAL AREA TUESDAY.
LATEST MODEL GUIDANCE INDICATED A WET PATTERN IS FORECAST TO
AFFECT THE REGION BEGINNING ON TUESDAY AND LASTING THROUGH AT LEAST
THURSDAY. LATEST SJU-GFS COMPUTER MODEL INDICATED PRECIPITABLE
WATER VALUES WILL RISE TO NEAR 2.0 INCHES BY WEDNESDAY...WITH
THETAE VALUES AT 700MB MB RISING FROM 320K TODAY TO AROUND 330K BY
WEDNESDAY. IN ADDITION...WINDS BETWEEN 0-3 KM ARE EXPECTED TO
SHIFT SOUTHEASTERLY TUESDAY INTO FRIDAY...WHICH WILL BRING DEEP
TROPICAL MOISTURE TO THE AREA.

THIS WET PATTERN IS NOT EXPECTED TO EXIT THE LOCAL AREA THROUGH
NEXT WEEKEND...WHEN A HIGH PRESSURE RIDGE IS EXPECTED TO BUILD
ACROSS THE LOCAL AREA. AT THIS TIME...LOOKS LIKE THE WETTEST DAYS
WILL BE WEDNESDAY INTO THURSDAY AS UPPER LEVEL TROUGH COMBINE WITH
A SURFACE TROUGH TO AID IN THE DEVELOPMENT OF SHOWERS AND POSSIBLE
THUNDERSTORMS ACROSS THE LOCAL REGION. STAY INFORMED.

&&

.AVIATION...SHRA WILL BE MORE FREQUENT ACROSS THE FLYING AREA DURING
THE NEXT 24 HOURS AS AN APPROACHING UPPER LEVEL LOW MOVES OVER THE
ISLANDS. AS A RESULT...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE
IN PASSING SHRA. ESE WINDS OF 10-30 KT EXPECTED BELOW 15K FEET.


&&

.MARINE...WINDS OF UP TO 22 KNOTS WILL CONTINUE TODAY ACROSS THE
REGIONAL WATERS TO MAINTAIN ROUGH WIND GENERATED SEAS UP TO 8
FEET. CONDITIONS WILL BEGIN TO GRADUALLY IMPROVE AS WINDS SLOWLY
DECREASE TONIGHT AND TUESDAY. IN THE MEANTIME SMALL CRAFT
ADVISORIES REMAIN IN EFFECT FOR MOST OF THE LOCAL WATERS. PLEASE
REFER TO THE LATEST COASTAL WATERS FORECAST AND MARINE WEATHER
MESSAGE ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN
OFFICE.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 81 72 / 70 70 70 30
STT 84 73 82 75 / 70 70 70 40

[cycloneye]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST MON DEC 23 2013

CARIBBEAN SEA...

AN EARLIER 0258 UTC ASCAT-B PASS INDICATED A BROAD SWATH OF 25-
30 KT TRADE WINDS OVER THE CARIBBEAN FROM 10N-16N BETWEEN 72W-
78W WITH THE HIGHEST WINDS...30 KT...WITHIN 90 NM OF THE COAST
OF COLOMBIA. 15-20 KT TRADEWINDS WERE NOTED OVER THE REMAINDER
OF THE CARIBBEAN SEA. SCATTERED LOW TOPPED SHOWERS ARE OVER
HONDURAS...NICARAGUA...AND COSTA RICA. MORE SCATTERED
SHOWERS ARE OVER HISPANIOLA... PUERTO RICO...AND THE LEEWARD
ISLANDS. IN THE UPPER LEVELS...A LARGE UPPER LOW OVER THE
TROPICAL ATLC NEAR 21N62W WAS EXPANDING ITS INFLUENCE OVER THE
CARIBBEAN E OF 75W WHILE A NARROW RIDGE PREVAILED OVER THE BASIN
BETWEEN 75W AND 85W. STRONG SUBSIDENCE DOMINATED THE CARIBBEAN
WHILE UPPER LEVEL MOISTURE WAS ON THE INCREASE OVER THE FAR NE
CARIBBEAN AND LEEWARD ISLANDS. THE UPPER LEVEL LOW IS FORECAST
TO MOVE W IN TANDEM WITH A SURFACE TROUGH OVER PUERTO RICO IN
THE NEXT 24 HOURS WITH AN INCREASE IN SHOWER AND THUNDERSTORM
ACTIVITY OVER THE E CARIBBEAN AND THE NORTHERN LEEWARD ISLANDS.

[cycloneye]

Good afternoon. Plenty of rain is forecast to move thru the NE Caribbean islands in the next 24-48 hours so stay safe and dry. Stay tuned for more information as this event unfolds.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
308 PM AST MON DEC 23 2013

.SYNOPSIS...DEEPENING TUTT LOW CONTINUED TO SHIFT WEST SOUTHWEST
ACROSS THE NORTHEASTERN CARIBBEAN TODAY...WITH WESTERN PORTION OF THE
FORECAST AREA NOW UNDER A JET MAXIMUM NOW ROUNDING THE BASE OF THE
UPPER TROUGH. THIS IS PROVIDING GOOD VENTILATION AND UPPER LEVEL
DIVERGENCE. SURFACE HIGH PRESSURE REMAINS ANCHORED ACROSS THE
ATLANTIC NORTH OF THE REGION...WHILE AN INDUCED SURFACE TROUGH AND
ACCOMPANYING SURGE OF MOISTURE WITH AXIS NOW CROSSING THE LESSER
ANTILLES WILL CONTINUE WESTWARDS AND MOVE ACROSS THE REGION DURING
THE NEXT 24-48 HOURS. EXPECT A GRADUAL LOOSENING OF THE SURFACE
PRESSURE GRADIENT AND CONSEQUENTLY DIMINISHING NORTHEASTERLIES
OVERNIGHT THROUGH EARLY TUESDAY...WITH WINDS BECOMING SOUTHEASTERLY
BY TUESDAY AFTERNOON. THE COMBINATION OF THE DEVELOPING TUTT LOW
AND THE APPROACHING LOW LEVEL TROUGH WILL ENHANCE CONVECTION ACROSS
THE REGIONAL WATERS AND PARTS OF THE ISLANDS ESPECIALLY BETWEEN EASTERN
PUERTO RICO AND THE NORTHERN LEEWARDS.

&&

.DISCUSSION...EXPECT A CONTINUED DETERIORATION IN THE OVERALL WEATHER
CONDITIONS WITH INCREASING CLOUDINESS AND MOISTURE CONVERGENCE ACROSS
THE REGION DURING THE REST OF THE AFTERNOON AND THROUGH TUESDAY. LATEST
MODEL GUIDANCE AS WELL AS PRESENT SATELLITE IMAGERY...ALL SUGGEST
THAT THE TUTT LOW IS TO RETROGRESS WESTWARD OVER PUERTO RICO BY EARLY
TUESDAY...THEN MEANDER IN ITS VICINITY THROUGH AT LEAST CHRISTMAS
DAY. UNDER THESE UNSTABLE UPPER LEVEL CONDITIONS AND THE INCREASING
MOIST SOUTHEASTERLY WIND FLOW... EXPECT A MOSTLY WET AND ACTIVE WEATHER
PATTERN WITH PERIODS OF ENHANCED CONVECTION ACROSS PARTS OF THE ISLANDS
AND SURROUNDING WATERS THROUGH AT LEAST EARLY WEDNESDAY/CHRISTMAS DAY.
THEREFORE... WITH THE PRESENT CONDITIONS AND EXPECTED WEATHER SCENARIO...
THERE IS HIGH POTENTIAL FOR DEVELOPMENT OF ISOLATED BUT STRONG THUNDERSTORMS
IN SOME AREAS WITH PERIODS OF MODERATE TO LOCALLY HEAVY RAINFALL AND
ACCOMPANYING STRONG WINDS GUSTS OVERNIGHT THROUGH TUESDAY. BASED ON
THE PRESENT WIND FLOW AND THE FAVORABLE UPPER LEVEL CONDITIONS...THE
AREAS TO BE MOST AFFECTED OVERNIGHT THROUGH THE MORNING HOURS SHOULD
BE ALONG THE NORTHERN HALF AND EAST SECTION OF PUERTO RICO AS WELL
AS OVER...CULEBRA...VIEQUES AND THE VIRGIN ISLANDS. A GRADUAL IMPROVEMENT
IN WEATHER CONDITIONS IS EXPECTED BY THURSDAY AND FRIDAY FRIDAY...AND
INTO THE UPCOMING WEEKEND...DURING WHICH TIME THE HIGH PRESSURE RIDGE
ALOFT SHOULD BUILD ACROSS THE REGION FROM THE WEST...AND THE TUTT SHOULD
BEGIN TO FILL AND PULL EAST AND NORTH OF THE FORECAST AREA. BY SUNDAY
WINDS WILL AGAIN BECOME MORE EASTERLY AS SURFACE HIGH REESTABLISHES
ONCE AGAIN NORTHEAST OF THE REGION.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE IN PASSING
SHRA. VCTS AND SHRA WILL BE MORE FREQUENT ACROSS THE FLYING AREA
DURING THE NEXT 24 HOURS AS AN APPROACHING UPPER LEVEL LOW AND
SURFACE TROUGH MOVES ACROSS THE ISLANDS FROM THE EAST. WINDS FROM
THE ENE AT 10-25 KT EXPECTED FM SFC UP TO 15 KFT AT LEAST UNTIL THE
END OF THE FCST PERIOD.

&&

.MARINE...WINDS OF UP TO 22 KNOTS WITH OCCASIONALLY HIGHER GUSTS
CONTINUED ACROSS THE LOCAL WATERS TODAY...TOO MAINTAIN ROUGH AND
HAZARDOUS SEAS UP TO 8 FEET. MARINE CONDITIONS ARE STILL EXPECTED
TO GRADUALLY IMPROVE AS THE TRADE WINDS DIMINISH OVERNIGHT THROUGH
TUESDAY. IN THE MEANTIME...SMALL CRAFT ADVISORIES REMAIN IN EFFECT
FOR MOST OF THE LOCAL WATERS. PLEASE REFER TO THE LATEST COASTAL
WATERS FORECAST AND MARINE WEATHER MESSAGE ISSUED BY THE NATIONAL
WEATHER SERVICE WFO SAN JUAN OFFICE.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 71 81 72 83 / 70 70 30 40
STT 73 84 74 83 / 70 70 40 60

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1017 PM AST MON DEC 23 2013

.UPDATE...LATEST RADAR AND SATELLITE IMAGES THIS EVENING
DEPICTED SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS MOSTLY
ACROSS THE CARIBBEAN AND THE ATLANTIC COASTAL WATERS. THIS ACTIVITY
WAS ASSOCIATED WITH AN UPPER LEVEL TROUGH JUST OVER THE NORTHEAST
CARIBBEAN. THE GFS MODEL GUIDANCE INDICATED THAT THE UPPER LOW WILL
MEANDER OVER THE REGION UNTIL AT LEAST THURSDAY. LATEST SURFACE
ANALYSIS DEPICTED A WELL DEFINED INDUCED SURFACE TROUGH DEVELOPING
JUST ACROSS THE LOCAL ISLANDS TONIGHT. THESE FEATURES WILL COMBINE
TO PRODUCE AN UNSTABLE AIR MASS OVER THE NORTHEAST CARIBBEAN FOR THE
NEXT FEW DAYS.

WEATHER CONDITIONS WILL CONTINUE TO DETERIORATE TONIGHT WITH
INCREASING CLOUDINESS ACROSS THE REGION. THIS WET WEATHER PATTERN
WILL CONTINUE FOR THE NEXT FEW DAYS. EXPECT A MOSTLY WET AND
ACTIVE WEATHER PATTERN WITH PERIODS OF ENHANCED CONVECTION ACROSS
PARTS OF THE ISLANDS AND SURROUNDING WATERS THROUGH AT LEAST EARLY
THE CHRISTMAS DAY.

[cycloneye]

Good morning. A mainly rainy day is expected today in PR and VI as a trough lingers nearby.


AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
553 AM AST TUE DEC 24 2013

.SYNOPSIS...UPPER LEVEL TROUGH WILL LINGER ACROSS THE AREA THROUGH
THURSDAY. SURFACE TROUGH WILL MOVE ACROSS THE AREA LATE TONIGHT
INTO WEDNESDAY. ACTIVE WEATHER WITH SCATTERED TO NUMEROUS
SHOWERS WITH ISOLATED STRONG THUNDERSTORMS WILL CONTINUE TO
AFFECT THE LOCAL ISLANDS THROUGH THURSDAY.

&&

.DISCUSSION...DEEP UPPER LEVEL TROUGH IS THE MAIN WEATHER FEATURE
AFFECTING THE LOCAL WEATHER CONDITIONS. LATEST SATELITE AND RADAR
IMAGES ARE SHOWING AN EXTENSIVE AREA OF SHOWERS AND THUNDERSTORMS
OVER PUERTO RICO...WHICH EXTEND SEVERAL HUNDREDS MILES TO THE NORTH
AND NORTHEAST OF THE AREA. THIS AREA OF ACTIVE WEATHER IS FORECAST
TO LINGER ACROSS THE AREA THROUGH AT LEAST THURSDAY...AS THE UPPER
LEVEL TROUGH MEANDER NEAR THE REGION. THIS UPPER LEVEL TROUGH WILL
INTERACT WITH A SURFACE TROUGH WHICH WILL MOVE ACROSS THE LOCAL
AREA TONIGHT INTO WEDNESDAY. BOTH FEATURES PROMISE TO MAINTAIN
ACTIVE WEATHER ACROSS THE REGION THROUGH AT LEAST THURSDAY. IN
ADDITION...SURFACE WINDS ARE EXPECTED TO SHIFT SOUTHEASTERLY AND
EVEN SOUTHERLY THROUGH THE END OF THE WEEK. THIS WIND FLOW WILL
TRANSPORT DEEP TROPICAL MOISTURE ACROSS THE AREA...AND WILL
ENHANCE THE SHOWER AND THUNDERSTORM ACTIVITY MAINLY IN THE
AFTERNOON HOURS.

ISOLATED STRONG THUNDERSTORMS CAN BE EXPECTED ONCE AGAIN TODAY AND
WEDNESDAY AS COLD AIR AT MID LEVEL OF THE ATMOSPHERE CONTINUE TO
PROMOTE UNSTABLE ENVIRONMENT. THEREFORE...SOME OF THESE STORMS
COULD PRODUCE TORRENTIAL RAINFALL...FREQUENT LIGHTING AND STRONG
GUSTY WINDS. SMALL HAIL IS ALSO POSSIBLE DUE TO LOWER THAN NORMAL
TEMPERATURES AT MID LEVELS TODAY AND WEDNESDAY. WEATHER CONDITIONS
ARE EXPECTED TO IMPROVE BY THE WEEKEND AS UPPER LEVEL RIDGE BUILDS
ACROSS THE REGION.

&&

.AVIATION...PERIODS OF MVFR CONDITIONS AND MOUNTAIN OBSCURATIONS WILL
REMAIN POSSIBLE AT ALL TAF SITES DURING THE FORECAST PERIOD AS UPPER
LEVEL LOW CONTINUES TO ENHANCE SHOWER AND THUNDERSTORM ACTIVITY
ACROSS THE FLYING AREA. EASTERLY WINDS EXPECTED THROUGH AT LEAST
TOMORROW MORNING BECOMING SOUTHERLY THIS AFTERNOON.

&&

.MARINE...DUE TO LATEST BUOY OBSERVATIONS AS WELL AS CURRENT
MODEL GUIDANCE...THE SMALL CRAFT ADVISORY WAS EXTENDED THROUGH
MIDNIGHT TONIGHT AS HAZARDOUS MARINE CONDITIONS WILL CONTINUE.
SEAS UP TO 9 FEET AND WINDS UP TO 21 KNOTS ARE EXPECTED. PLEASE REFER
TO THE LATEST COASTAL WATERS FORECAST AND MARINE WEATHER MESSAGE
ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN OFFICE.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 81 73 / 70 30 60 20
STT 83 73 84 75 / 70 40 60 20