Caribbean - Central America Weather

[cycloneye]

Good afternoon. The scattered showers pattern will continue at least thru next Wednesday.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST SUN DEC 1 2013

.SYNOPSIS...AT UPPER LEVELS...A BROAD UPPER LEVEL TROUGH WILL PASS
THROUGH THE AREA TONIGHT LEAVING US IN THE LEFT ENTRANCE OF A 70
KNOT TROPICAL JET TONIGHT AND MONDAY. A WEAK TROUGH WILL PASS WEDNESDAY
FOLLOWED BY A SHARPENING TROUGH ON THURSDAY. TROUGHINESS WILL
BECOME ALMOST EAST-WEST ACROSS THE AREA AS IT LEANS OVER DURING
THE WEEKEND.

AT MID LEVELS...A WEAK TROUGH OVER THE LESSER ANTILLES WILL MOVE
EAST AND WEAKEN. ON TUESDAY HIGH PRESSURE WILL BUILD OVER THE
CARIBBEAN AS WESTERLIES PREVAIL OVER THE ATLANTIC WATERS TO THE
NORTH. THEN STRONG HIGH PRESSURE WILL BUILD OVER WESTERN CUBA AS A
TROUGH DIGS SOUTHWEST OVER THE LOCAL AREA THURSDAY. THIS HIGH
PRESSURE WILL GRADUALLY MOVE EAST TO NORTH OF PUERTO RICO AND THE
U.S. VIRGIN ISLANDS. EXCEPT FOR THIS THURSDAY AND FRIDAY
CONDITIONS AT MID LEVELS WILL BE MOSTLY DRY UNTIL THE FOLLOWING
MONDAY.

AT LOWER LEVELS...WEAK HIGH PRESSURE WILL RIDGE SOUTH INTO THE
TROPICAL ATLANTIC AS LOW PRESSURE FORMS IN THE WESTERN ATLANTIC
MONDAY AND TUESDAY CAUSING SOUTHEAST FLOW. EARLY WEDNESDAY HIGH
PRESSURE WILL FORM IN THE WESTERN ATLANTIC BEHIND THE LOW AND
BUILD EAST ACROSS THE ATLANTIC JUST ABOVE 30 DEGREES NORTH
LATITUDE...INCREASING THE LOCAL TRADE WINDS AS IT DOES SO. THE HIGH
PRESSURE WILL CONTINUE IN THE CENTRAL ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.

&&

.DISCUSSION...LIGHT SURFACE WINDS FROM THE EAST ALLOWED SEA
BREEZES TO DEVELOP OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS
TODAY WHILE SHOWERS FORMED OVER THE CARIBBEAN WATERS AND MOVED
OVER VIEQUES AND CULEBRA AND THUNDERSTORMS HOVERED OVER THE WATERS
JUST NORTH OF OUR FORECAST AREA. THUNDERSTORMS WERE FORMING OVER
NORTHWEST INTERIOR PUERTO RICO AT ISSUANCE TIME. AS HIGH PRESSURE
BUILDS SOUTH INTO THE TROPICAL ATLANTIC...FLOW JUST ABOVE THE
SURFACE WILL REMAIN SOUTHEAST TO SOUTH UNTIL WEDNESDAY. THIS WILL
BE A FAIRLY MOIST FLOW THAT WILL KEEP SCATTERED SHOWERS IN THE
FORECAST FOR MOST OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS.
AMOUNTS ARE EXPECTED TO BE MODEST OWING TO THE LACK OF STRONG
FORCING MECHANISMS ALTHOUGH SOME THUNDERSTORMS SHOULD BE EXPECTED.
AFTER WEDNESDAY...HIGH PRESSURE BUILDS ACROSS THE ATLANTIC JUST
NORTH OF 30 DEGREES NORTH AND WILL INCREASE THE TRADE WIND FLOW
ACROSS THE AREA. MOISTURE THEN REMAINS SHALLOW. NEVERTHELESS
RELATIVE HUMIDITIES AT 925 MB REMAIN IN THE LOW 90S AND PASSING
SHOWERS MUST BE EXPECTED ON THE WINDWARD COASTS WITH SOME
AFTERNOON CONVECTION PROBABLE IN THE INTERIOR VALLEYS ON THE
OPPOSITE SIDE INTO THE BEGINNING OF NEXT WEEK.

&&

.AVIATION...VFR XCP IFR/MVFR IN SOME SCT SHRA/TSRA THRU EARLY EVE.
THEN SCT IFR/MVFR IN SHRA/TSRA E-ESE PR AND USVI OVERNITE INTO MON.
WINDS SFC-FL100 ESE 10-15 KT BCMG SE 5-12 KT ON MON AND S MON
NITE. AREAS OF MTN OBSCURATIONS THRU THE PD.


&&

.MARINE...SEAS ARE EXPECTED TO CONTINUE TO SUBSIDE SLOWLY THROUGH
WEDNESDAY. WINDS WILL INCREASE OVER THE AREA AS HIGH PRESSURE
BUILDS TO THE NORTH LATER IN THE WEEK AND SEAS WILL THEN INCREASE.
SEAS WILL BE CHOPPY WITH GENERALLY SHORT PERIODS THEN. SMALL
CRAFT ADVISORIES WILL LIKELY BE NECESSARY IN THE OUTER ATLANTIC
WATERS THE FOLLOWING WEEKEND. IN THE MEANTIME...SMALL CRAFT SHOULD
EXERCISE CAUTION IN THE ATLANTIC WATERS AND NORTHERN PORTIONS OF
THE CARIBBEAN PASSAGES TONIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 84 74 85 / 40 40 30 30
STT 74 85 76 85 / 60 40 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1006 PM AST SUN DEC 1 2013

.UPDATE...LATEST SATELLITE IMAGES THIS EVENING DEPICTED A SMALL AREA
OF MOISTURE JUST ACROSS THE NORTHEAST CARIBBEAN THIS EVENING.
HOWEVER...DOPPLER WEATHER RADAR INDICATED A GENERAL DECREASE IN
SHOWERS AND THUNDERSTORMS ACROSS THE REGION. AT THIS TIME ONLY
ISOLATED TO SCATTERED SHOWERS ARE OBSERVED MOSTLY ACROSS THE
SURROUNDING COASTAL WATERS BUT NO SIGNIFICANT PRECIPITATION WAS
DETECTED OVER LAND AREAS SO FAR THIS EVENING. THE COMBINATION OF A
DEVELOPING SURFACE LOW PRESSURE SYSTEM ACROSS THE EASTERN UNITED
STATES SEABOARD AND A SURFACE HIGH PRESSURE OVER FLORIDA...WILL
MAINTAIN A SOUTHEAST LOW LEVEL WIND FLOW AT LEAST UNTIL THE MIDDLE
OF THE WEEK. THIS WIND FLOW BE A FAIRLY MOIST FLOW THAT WILL KEEP
SCATTERED SHOWERS IN THE FORECAST FOR MOST OF PUERTO RICO AND THE
U.S. VIRGIN ISLANDS.

[cycloneye]

Good morning. No big changes are expected today in PR and VI as scattered showers will continue to move thru the area.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
535 AM AST MON DEC 2 2013

.SYNOPSIS...SEVERAL MID TO UPPER LEVEL PERTURBATIONS WILL MOVE
OVER THE LOCAL AREA THROUGH FRIDAY. THEN...AN UPPER LEVEL TROUGH
WILL AMPLIFY JUST EAST OF THE AREA DURING THE WEEKEND. THIS INFLUX
OF MID-UPPER LEVEL ENERGY WILL CAUSE SOME DESTABILIZATION OF THE
ATMOSPHERE IN THE ISLAND VICINITY...FAVORING SCATTERED CONVECTION
ACROSS THE ISLANDS THROUGH AT LEAST FRIDAY.

&&

.DISCUSSION...HIGH PRESSURE OVER THE NORTH CENTRAL ATLANTIC WILL
MAINTAIN A GENTLE SOUTHEAST TO SOUTH FLOW UNTIL WEDNESDAY. THIS
WEAK FLOW WILL ALLOW LOCAL SEA BREEZES TO DEVELOP EACH AFTERNOON
ACROSS MAINLAND PUERTO RICO. ALTHOUGH...MOISTURE WILL BE NEAR NORMAL
THIS WEEK...A SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE ACROSS
THE LOCAL ISLANDS...KEEPING THE ATMOSPHERIC CONDITIONS RELATIVELY
UNSTABLE. THIS PATTERN WILL FAVOR THE DEVELOPMENT OF THUNDERSTORM
AS WELL AS LOCALLY HEAVY RAINFALL IN PORTIONS OF THE FORECAST
AREA. AFTER WEDNESDAY...HIGH PRESSURE WILL BUILD NORTH-NORTHWEST
OF THE ISLANDS...INCREASING THE TRADE WINDS ACROSS THE NORTHEAST
CARIBBEAN. THIS BRISK NORTHEAST FLOW WILL DOMINATE THE FORECAST
AREA...FAVORING THE SHALLOW CONVECTION ACROSS THE NORTH COAST OF
PUERTO RICO AND THE U.S. VIRGIN ISLANDS. FORECAST CHARTS INDICATE
BULK OF THE UPPER LEVEL DISTURBANCES SHOULD EXIT THE REGION BY
FRIDAY. THEN...AN UPPER CONVERGENT PATTERN WILL ESTABLISH OVER THE
WEEKEND AS A UPPER LEVEL TROUGH AMPLIFIES WEST OF THE REGION. IF
THIS VERIFIES...OUR AREA WILL BE UNDER A GENERALLY STABLE AIRMASS
DURING THE WEEKEND.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE TO PREVAIL AT ALL TAF SITES
THROUGH AT LEAST 02/18Z. BRIEF PERIODS OF MVFR CONDITIONS WITH
MOUNTAIN OBSCURATIONS CAN BE EXPECTED OVER TJMZ AND TJBQ IN SHRA/TSRA
THIS AFTERNOON. WINDS WILL CONTINUE MAINLY SOUTHEAST AT AROUND 10
KTS.

&&

.MARINE...SEAS WILL CONTINUE TO SUBSIDE SLOWLY THROUGH WEDNESDAY.
THEN...WINDS WILL INCREASE OVER THE AREA AS HIGH PRESSURE BUILDS
TO THE NORTH LATER IN THE WEEK AND SEAS WILL BE SLIGHTLY CHOPPY
FROM WEDNESDAY THROUGH FRIDAY. DURING THE WEEKEND...LONG PERIOD
NORTHEAST SWELLS WILL INVADE THE LOCAL WATERS...INCREASING THE
WAVE HEIGHTS TO 7-8 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 85 74 / 30 30 30 50
STT 86 74 86 76 / 60 30 30 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
252 PM AST MON DEC 2 2013

.SYNOPSIS...
A DEEP LAYERED MID TO UPPER LEVEL SHORT WAVE TROUGH EXTENDS OVER
PUERTO RICO INTO THE CENTRAL CARIBBEAN. THIS IS SUPPORTED BY A LOW
LEVEL INVERTED TROUGH WHICH HAS NOW MOVED ACROSS HISPANIOLA. UPPER
HIGH PRESSURE RIDGE CONTINUED TO SPREAD SOUTHWEST ACROSS THE NORTHEASTERN
CARIBBEAN FROM THE TROPICAL ATLANTIC. THIS GENERAL PATTERN WILL MAINTAIN
A FAIRLY MOIST SOUTHEASTERLY WIND FLOW THROUGH TUESDAY. THEREAFTER THE
WIND FLOW WILL GRADUALLY BECOME MORE EASTERLY THEN NORTHEASTERLY DURING
THE LATER PART OF THE WORK WEEK...AS SURFACE HIGH PRESSURE REESTABLISHES
ITSELF NORTH OF THE AREA ON THURSDAY INTO FRIDAY. THE AFOREMENTIONED
SHORT WAVE TROUGH IS EXPECTED TO EVENTUALLY FILL AS IT PULLS FURTHER
AWAY FROM THE REGION TODAY. MEANWHILE ANOTHER TROUGH WILL CONTINUE
TO EXIT THE EASTERN UNITED STATES AND MOVE WESTWARDS INTO THE
SOUTHWESTERN ATLANTIC BY WEDNESDAY...THEN FINALLY SINK SOUTH AND
LINGER ACROSS THE NORTHEASTERN CARIBBEAN ON THURSDAY AND FRIDAY.

&&

.DISCUSSION...EARLIER TJSJ 12Z UPPER AIR SOUNDING DATA AS WELL AS
SATELLITE IMAGERY AND DOPPLER WEATHER RADAR...ALL SUGGESTED FAIR
AMOUNTS OF LOW TO MID LEVEL MOISTURE ADVECTION ACROSS THE REGION
WITH LAYERED PWAT VALUES RANGING BETWEEN 1.50 AND 1.80 INCHES.
EXPECT THIS TO BE SUFFICIENT TO ALLOW FOR SOME LOCAL TERRAIN AND
SEA BREEZE INDUCED SHOWERS AND ISOLATED THUNDERSTORMS DURING THE
REST OF THE AFTERNOON MAINLY ACROSS PUERTO RICO. THE PREVAILING
SOUTHERLY FLOW SHOULD STEER MOST OF THE ACTIVITY TOWARDS THE
CENTRAL AND NORTHWEST SECTIONS OF PUERTO RICO. VARIABLY CLOUDY
SKIES AND LESSER SHOWER ACTIVITY IS EXPECTED ACROSS THE VIRGIN
ISLANDS DURING THE REST OF THE AFTERNOON HOURS.

BY LATE EVENING AND OVERNIGHT ANOTHER SURGE OF MOISTURE IS FORECAST
TO REACH THE COASTAL AREAS OF THE ISLANDS. THIS WILL BRING PERIODS
OF OVERNIGHT AND EARLY MORNING PASSING SHOWERS TO THE REGION ONCE
AGAIN. A GRADUAL CLEARING IS FORECAST BY MID MORNING ON TUESDAY
WITH ANOTHER ROUND OF LOCAL SEA BREEZE AND DIURNALLY INDUCED SHOWERS
ACROSS PARTS OF THE ISLANDS DURING THE AFTERNOON HOURS. EXPECT THIS
GENERAL PATTERN TO CONTINUE FOR THE NEXT SEVERAL DAYS AS OCCASIONAL
PATCHES OF MOSTLY SHALLOW TRADE WIND MOISTURE WILL PROPAGATE WESTWARD
ACROSS THE REGION FROM TIME TO TIME. THE PREVIOUSLY MENTION SECONDARY
SHORT WAVE SHOULD MOVE THROUGH THE AREA DURING THE LATTER PART OF THE
WEEK...HOWEVER STILL EXPECT MOST OF THE REGION TO REMAIN ON THE
CONVERGENT/SUBSIDENT SIDE OF THIS TROUGH. THEREFORE ALTHOUGH
BRIEF CONVECTIVE DEVELOPMENT WILL REMAIN POSSIBLE IN SOME AREAS...
DO NOT EXPECT ANY WIDESPREAD OR SIGNIFICANT ENHANCEMENT OF THE
SHOWER ACTIVITY AT THIS TIME FOR THE REST OF THE WEEK...AND INTO
THE WEEKEND WHEN CONDITIONS ARE EXPECTED TO BE SOMEWHAT DRIER AND
STABLE AS MAINLY COOLER NORTHERLY WIND FLOW SHOULD PREVAIL.

&&

.AVIATION...VFR CONDITIONS...WITH SOME VCSH...WILL CONTINUE TO
PREVAIL AT MOST TAF SITES...AS BRIEF PERIODS OF MVFR CONDITIONS WITH
MOUNTAIN OBSCURATIONS CAN BE EXPECTED OVER TJMZ AND TJBQ IN SHRA/ISOLD
TSRA TIL 02/21Z. VFR ONCE AGAIN DOMINATES THIS EVENING WITH SOME PASSING
VCSH EN ROUTE BTW ISLANDS. WINDS WILL CONTINUE MAINLY VARIABLY AT 10
KTS OR LESS...WITH SOME LOCALIZED GUSTS AROUND 15 KTS WITH PASSING
SHOWERS. LOW LEVEL WINDS WILL CONTINUE FM SE AT 5 TO 15 KTS UP TO
AROUND FL150...BCMG FM W AND INCR W/HT TO MAX WND OF 60-70 KTS NR
FL400.

&&

.MARINE....SEAS WILL CONTINUE TO SUBSIDE SLOWLY THROUGH WEDNESDAY.
THEN...WINDS WILL INCREASE OVER THE AREA AS HIGH PRESSURE BUILDS
TO THE NORTH LATER IN THE WEEK. SEAS WILL BE SLIGHTLY CHOPPY FROM
WEDNESDAY THROUGH END OF WEEK. BY LATE FRIDAY AND INTO THE UPCOMING
WEEKEND...LONG PERIOD NORTHEAST SWELLS WILL INVADE THE LOCAL WATERS...
BRINGING HAZARDOUS SEAS AND INCREASING THE WAVE HEIGHTS ONCE AGAIN
TO 7-8 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 85 73 83 / 30 30 50 50
STT 76 86 76 86 / 30 30 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1017 PM AST MON DEC 2 2013

.UPDATE...LATEST SATELLITE IMAGES THIS EVENING DEPICTED A SMALL AREA
OF MOISTURE JUST ACROSS THE CARIBBEAN WATERS. SCATTERED SHOWERS A
FEW THUNDERSTORMS ASSOCIATED WITH THIS AREA OF MOISTURE MOVED
ACROSS THE SOUTHERN SECTIONS OF PUERTO RICO EARLY THIS EVENING.
HOWEVER AT THIS TIME...DOPPLER WEATHER RADAR DETECTED A GENERAL
DECREASE IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION. THE
COMBINATION OF A SURFACE HIGH PRESSURE SYSTEM ACROSS THE NORTHWEST
ATLANTIC AND A DEVELOPING SURFACE LOW OVER THE EASTERN UNITED STATES
SEABOARD...WILL MAINTAIN A SOUTHEAST LOW LEVEL WIND FLOW AT LEAST
UNTIL THE MIDDLE OF THE WEEK. THIS WIND FLOW WILL CONTINUE TO
TRANSPORT BANDS OF TROPICAL MOISTURE ACROSS THE LOCAL ISLANDS AND
THE SURROUNDING COASTAL TONIGHT AND TOMORROW.

[cycloneye]

Good morning. A few scattered showers will move thru PR and VI today as a trough lingers nearby.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
525 AM AST TUE DEC 3 2013

.SYNOPSIS...SURFACE HIGH PRESSURE OVER THE NORTH CENTRAL ATLANTIC
WILL MAINTAIN A GENTLE TO MODERATE SOUTHEAST FLOW THROUGH EARLY
WEDNESDAY. THEN...FRESH EAST TO NORTHEAST SURFACE FLOW WILL DOMINATE
THE LOCAL REGION AS ANOTHER HIGH PRESSURE REESTABLISH OVER THE
WESTERN ATLANTIC. AT UPPER LEVELS...A POLAR TROUGH WILL EXIT THE
EASTERN UNITED STATES AND MOVE WESTWARDS INTO THE SOUTHWESTERN
ATLANTIC BY WEDNESDAY...THEN FINALLY SINK SOUTH AND MOVE ACROSS
THE NORTHEASTERN CARIBBEAN ON THURSDAY. MOISTURE WILL REMAIN ABOVE
NORMAL UNTIL THURSDAY NIGHT...DECREASING BELOW NORMAL FRIDAY INTO
THE WEEKEND.

&&

.DISCUSSION...A MOIST SOUTHERLY FLOW WILL CONTINUE TO ADVECT SCATTERED
SHOWERS ACROSS LOCAL AREA THIS MORNING. MOISTURE ADVECTION COMBINED
WITH SOME INFLUX OF MID-UPPER LEVEL ENERGY AND THE PROXIMITY OF
SUBTROPICAL JET ALOFT WILL KEEP THE SHOWERS AND THUNDERSTORMS IN
THE FORECAST THROUGH THURSDAY. FORECAST SOUNDING ARE SUGGESTING A
FAIRLY WEAK STEERING FLOW ACROSS THE REGION OVER THE NEXT FEW DAYS.
THIS WILL ALLOW LAND/SEA BREEZES TO PLAY A CRITICAL ROLE IN ISLAND
WEATHER...WITH AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPING OVER
THE LEEWARD SIDE OF THE ISLANDS...FOLLOWED BY A GENERAL CLEARING
AT NIGHT WITH LIGHT TO MODERATE SHOWERS OVER THE WINDWARD COASTS
AT NIGHT AND IN THE MORNING. THE BEST UPPER DYNAMICS ARE EXPECTED
ON THURSDAY AS THE AFOREMENTIONED UPPER LEVEL TROUGH DEEPENS NEAR
THE LOCAL ISLANDS. GFS ENSEMBLE SUGGEST THAT THE UPPER LEVEL TROUGH
WILL MOVE EAST OVER THE NORTHERN LEEWARD ISLANDS ON FRIDAY. IF
THIS VERIFIES...THE LOCAL AREA WILL REMAIN UNDER CONVERGENT SIDE
OF THE TROUGH...RESULTING IN GENERALLY STABLE PATTERN ACROSS THE
LOCAL ISLANDS DURING THE WEEKEND.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE TO PREVAIL AT ALL TAF SITES
THROUGH AT LEAST 03/18Z. BRIEF PERIODS OF MVFR CONDITIONS WITH
MOUNTAIN OBSCURATIONS CAN BE EXPECTED OVER TJMZ...TJBQ AND POSSIBLE
IN TJSJ IN SHRA/TSRA THIS AFTERNOON. WINDS WILL CONTINUE MAINLY SOUTH
SOUTHEAST AT AROUND 10 KTS...EXCEPT FOR SEA BREEZE VARIATIONS IN
COASTAL AREAS THIS AFTERNOON.

&&

.MARINE...SEAS WILL CONTINUE TO SUBSIDE SLOWLY THROUGH WEDNESDAY.
THEN...WINDS WILL INCREASE OVER THE AREA AS HIGH PRESSURE BUILDS
TO THE NORTH LATER IN THE WEEK. SEAS WILL BE SLIGHTLY CHOPPY FROM
WEDNESDAY THROUGH END OF WEEK. BY LATE FRIDAY AND INTO THE UPCOMING
WEEKEND...LONG PERIOD NORTHEAST SWELLS WILL INVADE THE LOCAL WATERS...
BRINGING HAZARDOUS SEAS AND INCREASING THE WAVE HEIGHTS ONCE AGAIN
TO 7-8 FEET.

&&

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

[cycloneye]

MARINE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
148 PM AST TUE DEC 3 2013

AMZ710-715-725-732-031915-
148 PM AST TUE DEC 3 2013

...STRONG THUNDERSTORMS OVER THE WATERS...

AT 140 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS...PRODUCING STRONG WINDS UP TO 33 KNOTS. THEY WERE ON
THE COASTAL WATERS FROM VIEQUES AND CULEBRA TO SAINT THOMAS...AND
NORTHWARD INTO THE ATLANTIC WATERS...AND THEY WERE MOVING
NORTH-NORTHEAST AT 15 KNOTS.

MARINERS CAN EXPECT GUSTY WINDS UP TO 33 KNOTS...LOCALLY HIGHER
WAVES...AND LIGHTNING STRIKES. BOATERS SHOULD SEEK SAFE HARBOR
IMMEDIATELY UNTIL THIS STORM PASSES.

INTENSE LIGHTNING WILL OCCUR WITH SOME OF THESE STORMS. IF CAUGHT ON
THE OPEN WATER STAY BELOW DECK IF POSSIBLE...KEEP AWAY FROM
UNGROUNDED METAL OBJECTS.

LAT...LON 1803 6500 1802 6579 1952 6513 1942 6442

$$
GV

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
307 PM AST TUE DEC 3 2013

.DISCUSSION...
SHOWERS/THUNDERSTORMS HAVE BEEN QUITE PERSISTENT ALL DAY FROM
CARIBBEAN OFFSHORE WATERS TO VIEQUES/CULEBRA TO NEAR ST. THOMAS
BUT HAVE NOT BEEN UNUSUALLY HEAVY. THEY PROBABLY ARE DEVELOPING IN
THE MOIST CONVERGENCE THAT GFS SHOWS NEAR USVI AT 18Z.

MOIST PLUME BEING DRAWN NORTHWARD FROM EASTERN CARIBBEAN ACROSS
PR/USVI WILL CONTINUE THROUGH WED NIGHT AND THEN BEGINS TO
DIMINISH ON THU AS LOW LEVEL FLOW BACKS TO THE NORTHEAST AND
DEEPENS. MOISTURE WILL BE DRIVEN SOUTH IN PROGRESSIVE SURGES THE
REST OF THE WEEK AND WEEKEND.

HIGHLY TILTED UPPER TROUGH TO PASS OVER REGION...PASSES OVER AT
250 MB ON WED AFTERNOON BUT NOT UNTIL THU AT 500 MB. PRECIPITABLE
WATER STILL AROUND 1.8 INCHES ON WED. STEERING FLOW WILL BE WEAK
SO IF THERE IS ANY THREAT OF FLOODING IT WILL BE IN SLOW MOVING
TSTORMS WED AFTERNOON. THEY COULD EASILY MOVE SLOW ENOUGH TO CUT
OFF THE MOISTURE FEED THAT STARTED THEM TO BEGIN. DYNAMICS DO NOT
LOOK VERY FAVORABLE BUT MAY LATER CONSIDER MENTIONING MINOR
FLOODING.

&&

.AVIATION...GENERALLY VFR BUT ISOLD IFR/MVFR PSBL IN SHRA/TSRA.
FEW OBSCD MTNS. LLVL FLOW SE LESS THAN 10 KT BCMG E EARLY WED...
THEN INCR NE INTO WED NIGHT.

&&

.MARINE...CONDITIONS BECOMING RELATIVELY TRANQUIL IN SHORT TERM.
LATE FRIDAY AND INTO THE UPCOMING WEEKEND...LONG PERIOD NORTHEAST
SWELLS STILL EXPECTED INTO LOCAL WATERS...BRINGING HAZARDOUS SEAS
AND INCREASING THE WAVE HEIGHTS ONCE AGAIN TO 7-8 FEET.

&&

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1045 PM AST TUE DEC 3 2013

.UPDATE...SHOWERS AND ISOLATED THUNDERSTORM ACTIVITY OVER PUERTO
RICO DIMINISHED OR MOVED OFFSHORE DURING THE LATE EVENING HOURS...
HOWEVER SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS WITH PERIODS
OF LOCALLY HEAVY RAINFALL CONTINUED TO MOVE FROM THE COASTAL WATERS
AND AFFECT PARTS OF THE NORTHERN VIRGIN ISLANDS AS WELL AS CULEBRA
AND VIEQUES.
MID TO UPPER LEVEL SHORT WAVE TROUGH JUST WEST OF THE AREA...CONTINUED
TO SHIFT EASTWARDS ACROSS THE SOUTHWEST ATLANTIC AND JUST NORTH OF
THE REGION. THIS WAS CREATING GOOD UPPER LEVEL VENTILATION/DIVERGENCE
ACROSS THE NORTHEASTERN CARIBBEAN. THIS SCENARIO ALONG WITH THE CONTINUED
MOIST EAST SOUTHEAST WINDS WAS ENHANCING AND WILL CONTINUE TO ENHANCE
CONVECTIVE DEVELOPMENT ACROSS THE LOCAL WATERS AND PARTS OF THE ISLANDS
OVERNIGHT AND ON WEDNESDAY. A FRONTAL SHEAR LINE NORTH OF THE REGION
STILL FORECAST TO EVENTUALLY SINK SOUTHWARDS ACROSS THE LOCAL AREA
AND AS HIGH PRESSURE RIDGE BUILDS ACROSS THE WEST AND SOUTHWEST ATLANTIC
DURING THE LATTER PART OF THE WEEK. THEREFORE...EXPECTED WINDS TO
EVENTUALLY BECOME MORE EAST TO NORTHEAST BY FRIDAY AND ALSO INCREASE
IN INTENSITY AS THE LOCAL PRESSURE GRADIENT TIGHTENS. MINOR CHANGES
MADE TO THE INHERITED FORECAST PACKAGE AT THIS TIME BASED ON PRESENT
AND EXPECTED WEATHER CONDITIONS DURING THE NEXT 24 HOURS.

[cycloneye]

Good morning. An upper trough will bring scattered showers today thru Thursday to PR and VI.


AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
545 AM AST WED DEC 4 2013

.SYNOPSIS...MID TO UPPER LEVEL RIDGE ACROSS THE EASTERN CARIBBEAN
WILL CONTINUE TO ERODE AS TROUGH ACROSS THE WESTERN ATLANTIC MOVES
EAST INTO THE CENTRAL ATLANTIC AND AMPLIFIES ACROSS THE EASTERN
AND CENTRAL CARIBBEAN. A SURFACE HIGH PRESSURE IS EXPECTED TO
ESTABLISH ITSELF NORTH OF THE LOCAL ISLANDS ON THURSDAY...TIGHTENING
THE LOCAL PRESSURE GRADIENT.

&&

.DISCUSSION...VARIABLY CLOUDY SKIES PREVAILED ACROSS THE LOCAL
ISLANDS OVERNIGHT. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY
WERE FOCUSED OVER THE LOCAL WATERS...WITH A FEW SPRINKLES ALSO
NOTED OVER E PR AND USVI. LOW TEMPERATURES WERE MAINLY IN THE MID
70S IN COASTAL AREAS AND THE WINDS WERE LIGHT AND VARIABLE.

APPROACHING UPPER LEVEL TROUGH WILL COMBINE WITH LOW LEVEL MOISTURE
TO RESULT IN PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS
THE LOCAL ISLANDS THROUGH AT LEAST THURSDAY. TODAY`S SHOWER/THUNDERSTORM
ACTIVITY WILL BE FOCUSED ACROSS E AND SE PR AS WELL AS USVI IN
THE LATE MORNING HOURS...SPREADING ACROSS THE CORDILLERA AND WEST
PR IN THE AFTERNOON. STEERING FLOW WILL BE WEAK...THEREFORE THESE
SLOW MOVING SHOWERS MAY CAUSE SHARP RISES ON SMALL STREAMS AS WELL
AS URBAN FLOODING.

LOW LEVEL MOISTURE WILL ERODE AND UPPER LEVEL DYNAMICS WILL BECOME
LESS FAVORABLE FOR SHOWER AND THUNDERSTORM DEVELOPMENT ON FRIDAY...
AS THE AFOREMENTIONED UPPER LEVEL TROUGH ESTABLISHES EAST OF THE
LOCAL AREA. THIS WILL RESULT IN A GENERALLY FAIR AND MAINLY STABLE
WEATHER PATTERN FRIDAY THROUGH AT LEAST EARLY NEXT WORK WEEK.
HOWEVER...PATCHES OF MOISTURE WILL CONTINUE TO MOVE ACROSS THE
LOCAL AREA FROM TIME TO TIME...BRINGING PASSING SHOWERS ACROSS THE
WINDWARD SIDE OF THE LOCAL ISLANDS.

&&

.AVIATION...VFR CONDS TO PREVAIL ACROSS THE LOCAL TERMINALS WITH
THE OCCASIONAL PASSING SHRA UNTIL 04/16Z. THEREAFTER...SHRA
INCREASES...LIKELY AFFECTING THE LOCAL TERMINALS. TJPS AND TJMZ
APPEAR TO HAVE THE HIGHEST CHANCE OF TSRA BETWEEN 04/17Z AND
04/22Z. VCTS WRITTEN IN TAF DUE TO SOME UNCERTAINTY ON EXACT
TIMING BUT SHRA/TSRA ARE EXPECTED TO AFFECT THE LOCAL AIRPORTS
TODAY...ESPECIALLY IN THE AFTERNOON. WIND FROM THE EAST TO EAST
NORTHEAST AT AROUND 10 KNOTS WITH SEA BREEZE VARIATIONS TODAY.

&&

.MARINE...CONDITIONS BECOMING RELATIVELY TRANQUIL IN SHORT TERM.
LATE FRIDAY AND INTO THE UPCOMING WEEKEND...LONG PERIOD NORTHEAST
SWELLS STILL EXPECTED INTO LOCAL WATERS...BRINGING HAZARDOUS SEAS
AND INCREASING THE WAVE HEIGHTS ONCE AGAIN TO 7-8 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 83 74 / 40 40 40 40
STT 86 75 85 75 / 50 40 40 40

[Annie Oakley]

Cycloneye.......
Puerto Rico is better off with you ha ha!
Have a safe winter, you and your family.
Annie O

[cycloneye]

Cycloneye.......
Puerto Rico is better off with you ha ha!
Have a safe winter, you and your family.
Annie O

Safe winter to you too. Merry Christmas and Happy New Year.

[cycloneye]

Good afternoon. It looks like the rainy pattern will continue for PR and VI for the next couple of days as troughs move thru.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
253 PM AST WED DEC 4 2013

.DISCUSSION...500 MB TROUGH CURRENTLY AT EASTERN HISPANIOLA WILL
GET A REINFORCING SURGE WHEN ANOTHER CURRENTLY NORTHWEST OF THAT
ISLAND CATCHES UP AND DRIVES THROUGH PR/USVI TONIGHT. THIS TROUGH
WILL DIG INTO THE EASTERN CARIBBEAN ALSO IN RESPONSE TO THE
QUICKLY BUILDING RIDGE FROM THE GULF OF MEXICO. SHOWERS WILL
LIKELY REMAIN SCATTERED TO NUMEROUS OVER COASTAL WATERS THIS
EVENING WITH DECREASING ACTIVITY OVERNIGHT. THE WIDESPREAD CLOUDS
TODAY KEPT RAINFALL FROM BECOMING VERY WIDESPREAD OR INTENSE ON
LAND THOUGH SOME AREAS WILL SEE LOCALIZED FLOODING INTO EVENING.

00Z ECMWF DETERMINISTIC MODEL SHOWED A CLOSED 500 MB LOW
DEVELOPING OVER EXTREME NORTHEAST CARIBBEAN BY FRI EVE AND THEN
FORCES IT SOUTHWEST AND ONTO THE COAST OF COLUMBIA BY SUNDAY. 12Z
ECMWF CONTINUED WITH THIS SCENARIO. THIS WOULD POTENTIALLY BE A
VERY WET SCENARIO FOR PR/USVI BUT THE ECMWF ENSEMBLE ONLY SHOWS A
TROUGH (SIMILAR TO GFS) THERE WITH A WIDE SPREAD IN SOLUTIONS. 12Z
ECMWF DETERMINISTIC RUN CONTINUED TO SHOW THE SAME SCENARIO BUT
HAVE NOT YET SEEN THE MOISTURE FIELDS FOR THIS MODEL OR ITS
ENSEMBLE.

12Z GFS CONTINUED ITS PREVIOUS TREND WITH A STRONG TROUGH
EXTENDING THROUGH THE CARIBBEAN THIS WEEKEND AND THE DOMINANT
RIDGE PROCEEDING TO PUSH SOUTHEAST RESULTING IN A DEFINITE DRY
PATTERN FOR PR/USVI. UKMET TAKES A MIDDLE APPROACH BUT WITHOUT
DEVELOPING A LOW THAT WOULD POSE A THREAT OF RETURNING MOISTURE
(AND FLOODING) FROM THE SOUTHEAST. SEE NO REASON TO LEAN TOWARDS
THE DETERMINISTIC ECMWF ATTM ESPECIALLY SINCE GFS DRIVES THE
PARENT TROUGH PROGRESSIVELY EASTWARD WITH A SIGNIFICANT JET
THROUGH THE TROUGH BASE AND LITTLE AVAILABLE JET TO DIG THE
CUTOFF. 00Z AND 12Z GFS ENSEMBLE RUNS SHOWED 2 OUT OF THE 12
MEMBERS SHOWING A CUTOFF DEVELOPING THOUGH WITH LESS POTENTIAL
FOR MOISTURE TO SURGE TOWARDS THE LOCAL AREA.

WITHOUT A CUTOFF UPPER LOW DEVELOPING IN THE CARIBBEAN PR/USVI
WILL DRY OUT UNDERNEATH THE SUBSIDENCE OF THE RIDGE IMPOSING FROM
THE NORTHWEST. EVEN IF THE UPPER LOW DID DEVELOP IT WOULD HAVE TO
DEVELOP DEEPLY ENOUGH BELOW 500 MB AND LAST LONG ENOUGH TO DRAW
TROPICAL MOISTURE BACK FROM THE SOUTHEAST. THE DRY SCENARIO IS
WHAT WE HAVE BEEN FORECASTING BEGINNING IN PROGRESSIVE DRY SURGES
AND WILL STICK WITH IT.

&&

.AVIATION...PERIODS OF MVFR/IFR CONDITIONS WILL BE LIKELY IN TJSJ AND
POSSIBLY TIST/TISX THE REST OF THE AFTERNOON. IN ADDITION...BRIEF
MVFR CONDS ARE ALSO POSSIBLE IN TJPS AND TJMZ. MOUNTAIN OBSCURATIONS
ARE LIKELY ACROSS THE INTERIOR AND MOUNTAIN SECTIONS OF PUERTO RICO
THRU 04/22Z. SHRA/TSRA WILL CONTINUE OVER THE REGIONAL WATERS THRU
LATE TONIGHT. WINDS WILL BE FROM THE EAST TO NE AT 5-10 KTS BLO 10K
FT.

&&

.MARINE...CONDITIONS REMAIN QUIET FOR NOW EXCEPT WHERE THUNDERSTORMS
ARE CAUSING GUSTY WIND AND LIGHTNING...WHICH WILL TAPER OFF OVERNIGHT.
NORTH-NORTHEAST SWELL STILL EXPECTED TO BEGIN FRI NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 82 73 82 / 60 40 30 40
STT 75 85 75 85 / 70 50 40 40

[Macrocane]

Update on the 3rd cold surge of the season in Central America (Nov 23-Nov 26): http://www.storm2k.org/phpbb2/viewtopic.php?f=22&t=106879&p=2360154#p2360154

The observations for last week's cold front are not updated yet.

[cycloneye]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1047 PM AST WED DEC 4 2013

.SYNOPSIS...UPPER LEVEL TROUGH AXIS WILL MOVE SLOWLY ACROSS
PR/USVI THRU THU THEN SHIFT SOUTH AND EAST OF THE AREA FRI WITH A
DRYING TREND EXPECTED. HIGH PRES OVR THE WRN ATLC WILL STRENGTHEN
THRU FRI WITH STRENGTHENING TRADE WINDS FRI NIGHT THRU EARLY NEXT
WEEK.

&&

.DISCUSSION...COOL WEATHER WILL PREVAIL THROUGH THE WEEKEND UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH. SHOWER CVRG AND INTENSITY
WILL GRADUALLY DIMINISH WITH EACH DAY AS MID-LEVEL DRY AIR SWEEPS
IN. TURNING SHARPLY DRIER SAT AND BECOMING WINDY UNDER INCREASING
UPPER LEVEL CONVERGENCE AND STRENGTHENING SFC HIGH PRES NEAR
BERMUDA. WARMER AND DRIER NEXT WEEK UNDER BUILDING UPPER LEVEL
RIDGE BUT REMAINING WINDY.

&&

.AVIATION...VRF CONDITIONS WITH VCSH ARE EXPECTED FOR ALL TAF SITES
DURING THE NIGHT. SFC WINDS WILL BE LIGHT AND VARIABLE...AND
MAINLY FROM THE E TO NE AT AROUND 10 TO 20 KTS UP TO 5 KFT.
SHRA/TSRA WILL BE POSSIBLE OVER THE ISLANDS AND REGIONAL WATERS
TOMORROW.

&&

.MARINE...STRENGTHENING TRADE WINDS FRI NIGHT AND ARRIVING LONG
PERIOD NORTHEAST SWELLS WILL MAKE FOR VERY DANGEROUS MARINE
CONDITIONS WITH CONFUSED SEAS AND DANGEROUS CONDITIONS ALONG THE
SURF ZONE. SFC WINDS ENE 20-25 KT WITH POSSIBLE GUSTS TO 30 KT
ACCORDING TO ECMWF 0.5KM WINDS. IT APPEARS WIND WAVES WILL BE MORE
DOMINANT THAT LONGER PERIOD SWELLS AND THIS IS LIKELY TO CREATE
VERY STEEP WAVES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 73 82 73 82 / 40 40 50 50
STT 75 85 75 85 / 40 40 30 30

[Macrocane]

Good weather with cool nights and warm days are expected for Central America. The latest HPC discussion:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
222 PM EST WED DEC 04 2013

DISCUSSION FROM DECEMBER 04/00UTC: DIGGING POLAR TROUGH OVER THE
WESTERN USA CONTINUES TO PRESS AGAINST A STRONG MID/UPPER LEVEL
RIDGE OVER MEXICO AND THE GULF. THE RIDGE HOLDS ITS GROUND THROUGH
24 HRS. BUT...BY 36-48 HRS IT STARTS TO YIELD TO THE TROUGH. BY 48
HRS THE TROUGH IS TO THEN EXTEND INTO THE NORTHWEST STATES OF
MEXICO/BAJA PENINSULA...TO SLOWLY PUSH EAST ACROSS NORTHERN MEXICO
THROUGH 72 HRS. AT LOW LEVELS THIS WILL SUSTAIN A SURFACE FRONT
THAT MOVES TO TEXAS THROUGH 36-48 HRS...INTO THE RIO BRAVO/
NORTHEASTERN MEXICO BY 48-60 HRS. BY 60-72 HRS THE FRONT IS TO
SURGE ACROSS TAMAULIPAS....WHERE IT WILL THEN REMAIN THROUGH 96
HRS. THE AMPLIFYING MID/UPPER TROUGH IS TO SUSTAIN A MOIST
ADVECTIVE PATTERN INTO THE NORTHWEST STATES OF MEXICO...WITH BEST
MOISTURE CONVERGENCE ALONG THE SIERRA MADRE OVER SONORA/WESTERN
CHIHUAHUA. IN THIS AREA EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 25-50MM/DAY BY 24-48 HRS. NOTE THAT THIS IS
CONSIDERABLY HIGHER THAN PREVIOUSLY ESTIMATED. AS THE FRONT ENTERS
NORTHEAST MEXICO...THIS IS TO THEN SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM BY 60-96 HRS.

A 250 HPA CLOSED HIGH OVER THE YUCATAN IS TO ANCHOR THIS RIDGE AS
IT EXTENDS ACROSS THE GULF INTO THE EASTERN USA TO CENTRAL
AMERICA. THROUGH 48 HRS THE HIGH RELOCATES TO EASTERN HONDURAS/
NICARAGUA...WHERE IT IS TO MEANDER THROUGH 72 HRS. AT 500 HPA...A
HIGH OVER THE YUCATAN ANCHORS THIS RIDGE. THROUGH 60-72 HRS THE
HIGH LIFTS TO SOUTH FLORIDA/NORTHWEST BAHAMAS. ASSOCIATED
RIDGE...MEANWHILE...IS TO BUILD ACROSS THE WESTERN TO CENTRAL
CARIBBEAN/NORTHERN PORTIONS OF COLOMBIA...WHILE PERSISTING ACROSS
CENTRAL AMERICA AND THE SOUTHERN STATES OF MEXICO. THIS RIDGE WILL
FAVOR A LARGE SCALE SUBSIDENCE PATTERN ACROSS THE
BAHAMAS-CUBA-CAYMAN ISLES TO CENTRAL AMERICA AND SOUTHERN MEXICO.
THIS IS TO CONTINUE INHIBITING ORGANIZED DEEP CONVECTION.

DOWNSTREAM FROM THIS AXIS...OVER THE ATLANTIC...AN AMPLIFYING
TROUGH DOMINATES FLOW NORTH OF THE ISLANDS WHILE FOCUSING SHORT
WAVE ENERGY ACROSS EASTERN HISPANIOLA TO PUERTO RICO-VIRGIN ISLES.
TROUGH IS TO SLOWLY PULL ACROSS THE NORTHEAST CARIBBEAN ISLES
THROUGH 42-48 HRS...WITH AXIS TO THEN AMPLIFY SOUTH AND WEST
ACROSS THE EASTERN CARIBBEAN TO NORTHERN SOUTH AMERICA. AS IT
MEANDERS OVER THE EASTERN CARIBBEAN AT 72-96 HRS...THE EUROPEAN
GLOBAL MODELS THEN FORECAST A LOW TO CLOSE ALONG THIS AXIS OVER
THE NORTHEAST CARIBBEAN. THE GFS...IN CONTRAST...FAVORS AN OPEN
TROUGH PATTERN TO PERSIST THROUGH 108-120 HRS. THE EUROPEAN MODELS
HAVE SHOWN STRONG CYCLE-TO-CYCLE CONSISTENCY IN THEIR FORECAST OF
THIS FEATURE...WHILE THE GFS CONTINUES TO MAKE PATTERN
CORRECTIONS. AS A RESULT...WE ARE LEANING TOWARDS THE DEEPER
EUROPEAN SOLUTION. AS IT PERSIST...THE LOW/TROUGH IS TO GENERALLY
FAVOR A DIVERGENT PATTERN ALOFT WHILE ALSO ENHANCING CONVECTIVE
INSTABILITY ACROSS THE NORTHEAST CARIBBEAN ISLES.

AT LOW LEVELS...ASSOCIATED POLAR TROUGH IS YIELDING TO A BUILDING
RIDGE OVER THE WESTERN ATLANTIC. THIS IS TO DISPLACE THE TROUGH
EAST AND NORTH AS THE CYCLE PROGRESSES. SURFACE FRONT...
MEANWHILE...IS TO MEANDER ACROSS THE BAHAMAS THROUGH 54-60 HRS.
BUT AS THE TROUGH PULLS AWAY...IT IS TO THEN FRONTOLIZE. THE
BUILDING RIDGE IS TO THEN SUSTAIN A FRESH NORTHEASTERLY FLOW
ACROSS THE GREATER ANTILLES TO THE CARIBBEAN...WHILE ALSO
TIGHTENING PRESSURE GRADIENT ACROSS THE BASIN. THIS...IN-TURN...IS
TO RESULT IN BOUNDARY LAYER WINDS OF 25-30KT. FURTHERMORE...THIS
IS TO THEN DRIVE A SHEAR LINE ACROSS HISPANIOLA TO THE MONA
PASSAGE THROUGH 24 HRS. THIS ENTERS PUERTO RICO-USVI BY 30-36
HRS...WHILE TRAILING ACROSS THE CARIBBEAN TO COSTA RICA/SOUTHERN
NICARAGUA. BY 48-54 HRS IT THEN RELOCATES TO THE LEEWARD
ISLES...MEANDERING INTO THE FRENCH/WINDWARD ISLES BY 60-72 HRS.
ACROSS PUERTO RICO-USVI THIS IS TO FAVOR RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM IN DEEP CONVECTION. OVER THE
LEEWARD ISLES EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA
OF 20-30MM. THROUGH 84-96 HRS CONVECTION IS TO BECOME MORE
ACTIVE/BETTER ORGANIZED...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-40MM. THIS IS TO CLUSTER BETWEEN EASTERN PUERTO RICO
AND THE NORTHERN LEEWARD ISLANDS. OVER EASTERN NICARAGUA...ALONG
THE TAIL END OF THE SHEAR LINE EXPECTING RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15MM BY 36-72 HRS. THIS IS TO THEN
PERSIST THROUGH 72-96 HRS DUE TO EASTERLY TRADE WIND CONVERGENCE.

THE EASTERN PACIFIC ITCZ LIES EAST ALONG THE SOUTH COAST OF PANAMA
TO THE EJE CAFETERO IN WESTERN COLOMBIA. ALTHOUGH CONVERGENCE ZONE
PERSISTS...INTENSIFYING TRADE WINDS CAP ACROSS THE CENTRAL/WESTERN
CARIBBEAN WILL LEAD TO GRADUAL DECREASE IN ACTIVITY OVER COLOMBIA
AND NORTHERN PORTIONS OF VENEZUELA. MOST ACTIVE IS EXPECTED ACROSS
SOUTHWEST COLOMBIA TO THE CENTRAL ANDEAN REGION...WHERE ITCZ
MOISTURE IS TO FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM IN ISOLATED TO SCATTERED CONVECTION. ACROSS AMAZONIA IN
VENEZUELA TO COLOMBIA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY
AND MAXIMA OF 15-25MM. OVER THE ATLANTIC...ITCZ ENTERS THE
CONTINENT OVER THE NORTHERN GUIANAS...WHERE IT IS TO GENERALLY
FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM. THROUGH
72 HRS THIS IS TO INCREASE AS MID/UPPER TROUGH DEEPENS ACROSS THE
EASTERN CARIBBEAN...PROVIDING VENTILATION ALOFT TO SCATTERED DEEP
CONVECTION. LATER IN THE CYCLE RAINFALL AMOUNTS ARE TO INCREASE TO
05-10MM/DAY AND MAXIMA OF 15-20MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL 24 36 48 60 72 84 96 TYPE

NONE.

FEARON...MSJ (JAMAICA)
DAVISON...WPC (USA)

[cycloneye]

Good morning. Scattered showers will move thru PR and VI today as a trough lingers nearby.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
441 AM AST THU DEC 5 2013

.SYNOPSIS...MID TO UPPER LEVEL TROUGH ACROSS THE WESTERN ATLANTIC
WILL CONTINUE TO MOVE EAST WITH ITS AXIS RELOCATING SOUTH AND EAST
OF THE LOCAL ISLANDS BY THE END OF THE WEEK. SURFACE HIGH PRESSURE
WILL CONTINUE TO AMPLIFY NORTH OF THE AREA...TIGHTENING THE LOCAL
PRESSURE GRADIENT.

&&

.DISCUSSION...CLOUDY SKIES PREVAILED ACROSS THE LOCAL ISLANDS
OVERNIGHT. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY WERE
FOCUSED OVER THE LOCAL WATERS...WITH A FEW SHOWERS NOTED OVER
E PR AND USVI. LOW TEMPERATURES WERE MAINLY IN THE MID 70S IN
COASTAL AREAS AND THE WINDS WERE LIGHT AND VARIABLE.

THE AFOREMENTIONED UPPER LEVEL TROUGH WILL CONTINUE TO COMBINE
WITH PLENTY OF LOW LEVEL MOISTURE TO RESULT IN PERIODS OF SHOWERS
AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL ISLANDS TODAY. SHOWER
AND THUNDERSTORM ACTIVITY WILL BE FOCUSED ACROSS THE EASTERN AND
NORTHERN PORTIONS OF THE FORECAST AREA...HOWEVER IF THERE IS A
GOOD BREAK IN CLOUD COVER...THE SOUTHWESTERN PORTIONS SHOULD
ALSO SEE SHOWER AND THUNDERSTORM DEVELOPMENT. DUE TO ALREADY
SATURATED SOILS...PROLONGED PERIODS OF MODERATE TO HEAVY RAINFALL
WILL LIKELY RESULT IN SHARP RISES IN SMALL STREAMS AND CREEKS AS
WELL AS URBAN FLOODING.

MODEL GUIDANCE CONTINUED TO SUGGEST A DECREASING TREND IN LOW
LEVEL MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS AS THE MID TO
UPPER UPPER LEVEL TROUGH RELOCATES SOUTH TO EAST OF THE LOCAL
AREA. AS A RESULT SHOWER COVERAGE AND INTENSITY IS EXPECTED TO
GRADUALLY DIMINISH WITH EACH DAY.

AN OVERALL DRIER WEATHER PATTERN WILL DOMINATE THE LOCAL AREA
SUNDAY INTO EARLY NEXT WORK WEEK. HOWEVER...PATCHES OF MOISTURE
WILL CONTINUE TO MOVE ACROSS THE LOCAL AREA FROM TIME TO TIME...
RESULTING IN A FEW PASSING SHOWERS ACROSS THE WINDWARD SIDE OF
THE LOCAL ISLANDS.

&&

.AVIATION...VFR CONDITIONS WITH VCSH ARE EXPECTED FOR ALL TAF SITES
DURING THE NIGHT WITH LIGHT AND VARIABLE SFC WINDS. SHRA AND ISOLD
TSRA EXPECTED TO AFFECT THE LOCAL TERMINALS TODAY CAUSING CIGS AT
AROUND FL050-080 WITH OCCASIONAL CIGS CLOSE TO FL030 WITH THE
HEAVIER RAIN. WIND WILL BE MAINLY FROM THE EAST NORTHEAST TODAY AT
AROUND 10KTS AND GUSTY NEAR SHRA.

&&

.MARINE....TRANQUIL MARINE CONDITIONS IN SHORT TERM. LATE FRIDAY
AND INTO THE UPCOMING WEEKEND...LONG PERIOD NORTHEAST SWELLS STILL
EXPECTED INTO LOCAL WATERS...BRINGING HAZARDOUS SEAS AND INCREASING
THE WAVE HEIGHTS ONCE AGAIN TO 7-8 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 74 83 74 / 50 50 50 60
STT 85 76 86 76 / 50 30 30 50

[cycloneye]

Here are some images of what occurred this morning as torrential rains moved over San Juan.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST THU DEC 5 2013

.DISCUSSION...500 MB TROUGH AXIS APPEARS TO DEFINE THE NORTHERN
BOUNDARY OF DEEP CONVECTION. THE LAST ROUND OF SHOWERS/ISOLATED
THUNDER IS APPROACHING THE NORTH SHORES THOUGH THEY LOOK MUCH LESS
OMINOUS THAN THE RAINS THAT OCCURRED EARLIER TODAY. EVEN THOSE ON
THE CARIBBEAN WATERS DO NOT LOOK IMPRESSIVE. SO HAVE KEPT SHOWERS
SCATTERED INTO EARLIER EVENING THEN GFS SHOWS THE TROUGH HAVING
PASSED INTO THE CARIBBEAN BY 00Z THIS EVENING. SHALLOWER SHOWERS
WILL KICK IN TONIGHT MORE TYPICAL IN NORTHEAST FLOW.

GFS/ECMWF/UKMET AGREE NOW IN CUTTING OFF THE TROUGH CURRENTLY
PASSING OVER AS AN UPPER LOW IN THE EASTERN CARIBBEAN...ECMWF
DOING SO SOONER THAN THE OTHER TWO. HOWEVER...THE VERY DOMINANT
RIDGE DEVELOPING INTO THE WESTERN ATLANTIC WILL PUSH EXTREMELY DRY
AIR SOUTHWARD AND ACROSS THE LOCAL ISLANDS. NONE OF THESE MODELS
APPEAR TO SUGGEST THAT THE LOW WILL DEVELOP WITH ENOUGH RETURN
FLOW TO PUSH HIGH MOISTURE LEVELS BACK TO PR/USVI. GFS AND ECMWF
700 MB HEIGHT FIELDS ARE ALMOST IDENTICAL THROUGH TUE/WED AND GFS
REBOUNDS PRECIPITABLE WATER TO 1.5 INCHES BY LATE MON ONLY TO THE
PR COASTAL WATERS (BARELY). SO HAVE NOT DEVIATED FROM OUR
ESSENTIALLY DRY FORECAST FOR THE NEXT WEEK.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDITIONS ARE EXPECTED ACROSS
TJSJ...TJBQ...TJPS...TIST AND TISX THIS EVENING. HOWEVER...WEATHER
CONDITIONS WILL IMPROVE LATE TONIGHT AND FRIDAY WITH LONG PERIODS OF
VFR CONDITIONS WITH VCSH FOR ALL TAF SITES AND LIGHT AND VARIABLE
SFC WINDS. WIND WILL BE MAINLY FROM THE EAST NORTHEAST TONIGHT AT
AROUND 10KTS AND GUSTY NEAR SHRA.

&&

.MARINE...BUOYS 41052/41053/41043 HAVE RISEN ABOUT A FOOT TODAY IN
RESPONSE TO INCREASING WINDS LOCALLY...PERIODS AROUND 5-6 SECONDS.
THESE WINDS CONTINUING WELL TO THE NORTHEAST WILL GRADUALLY DEVELOP
THE EXPECTED SWELLS TO REACH OUR NORTH SHORES...PROBABLY BY FRI
EVE.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 71 80 73 82 / 40 40 60 60
STT 73 84 75 85 / 30 30 50 50

[cycloneye]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
943 PM AST THU DEC 5 2013

.SYNOPSIS...DEVELOPING CUTOFF LOW NORTHEAST OF THE AREA WILL
RETROGRESS TOWARD PR EARLY NEXT WEEK THEN FILL. STRONG HIGH PRES
NEAR BERMUDA WILL TIGHTEN THE PRES GRADIENT WITH WINDY CONDITIONS
FRI NIGHT THRU MON.

&&

.DISCUSSION...DRYING TREND HAS BEGUN WITH PRECIPITABLE WATER DOWN
0.4 INCHES SINCE 12Z THU. STILL THE RISK OF SHOWERS TONIGHT
THROUGH 06Z SAT IN COOL AND UNSTABLE NORTHEAST FLOW BUT THESE WILL
BE SHALLOW AND NOTHING LIKE WE HAD YDAY OR TODAY. BY SAT...H85-H7
LAPSE RATES WEAKEN SIGNIFICANTLY AND MOISTURE SHRINKS WITH ONLY
SPOTTY VERY LIGHT SHOWERS AND BY SUN ATMS REALLY DRIES OUT WITH
PW LESS THAN AN INCH AND VERY LARGE 800 MB DEWPOINT DEPRESSIONS.
ONLY A FEW CLOUDS EXPECTED SUN OVR MOUNTAIN AREAS. IT WILL BECOME
NOTICEABLY WINDY ESPECIALLY OVR THE USVI...COASTAL AND HIGH
ELEVATIONS SUN AND MON AS PRESSURE GRADIENT TIGHTENS IN RESPONSE
TO STRONG HIGH PRES NEAR BERMUDA. WARMER AND MAINLY DRY BUT
WINDY NEXT WEEK UNDER RISING HEIGHTS ALOFT.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED ACROSS ALL TAF SITES TONIGHT.
SHRA AND VCSH MAINLY FOR TJSJ...TJBQ...TIST...AND TISX TOMORROW
MORNING. THEREAFTER...VCSH WITH LIGHT AND VARIABLE SFC WINDS FOR ALL
TAF SITES. 05/12Z SOUNDING INDICATED WINDS FROM THE E TO NE FROM 5
TO 30 KTS UP TO 5KFT.

&&

.MARINE...WINDS AND SEAS EXPECTED TO INCREASE FRI NIGHT ACROSS THE
ATLC AND CARIB WATERS. SEAS LIKELY TO BUILD TO 10 FT ATLC WATERS
AND 8 FT CARIB WATERS. WILL RAISE SEAS WITH NEXT CWF ISSUANCE.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 80 77 82 / 20 50 60 60
STT 78 84 76 85 / 20 30 50 50