[top]
000
FXCA62 TJSJ 220630 CCA
AFDSJU
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
228 AM AST SUN NOV 22 2009
.SYNOPSIS...MID LEVEL HIGH PRESSURE TO DOMINATE THROUGH THE
FORECAST PERIOD...ONLY ALLOWING FOR THE TYPICAL AFTERNOON SHOWERS
AND THUNDERSTORMS OVER WESTERN PUERTO RICO EACH AFTERNOON AND
NOCTURNAL PASSING SHOWERS OVER THE WATERS.
&&
.DISCUSSION...QUIET WEEK IN STORE AS MID LEVEL RIDGE KEEPS MID LAT
SYSTEMS MAINLY NORTH AND TROPICAL WEATHER TO OUR SOUTH NEXT 7
DAYS. SURFACE PRESSURE GRADIENT TO RETURN TO NORMAL TODAY OR
TOMORROW ALLOWING FOR WINDS TO RETURN BACK TO CLIMO DIRECTION AND
SPEED. VERY SIMPLE DIURNAL CONVECTIVE FORECAST FOR THE NEXT 7
DAYS. BY NEXT WEEKEND GFS SHOWS A POLAR FRONTAL PASSAGE OVER THE
LOCAL AREA...BUT RECENT RUNS HAVE SLOWED TIMING. UPDATED GRIDS TO
REFLECT THE CHANGE.
&&
.AVIATION...VFR ALL SITES EXCEPT TJMZ AND TJBQ WHERE MVFR TO IFR
TEMPO CONDS POSSIBLE 18Z-22Z. VA FROM MONTSERRAT APPEARS TO BE
MOVING WNW ON IR IMAGERY WITH TRAJECTORY TOWARD TISX. APPEARS THAT
ASH CLOUD NOT CLOSE ENOUGH TO TISX TO WARRANT IT IN THE
FORECAST...BUT APPROACHES FROM THE SOUTHEAST OR ROUTES GOING TO
THE LEEWARD ISLANDS SHOULD BE AWARE.
&&
.MARINE...WEAK NORTHEASTERLY SWELL ENERGY TO PERSIST THROUGH
MONDAY AFTERNOON WHEN MUCH LONGER PERIOD ENERGY (12-14 SECONDS)
ARRIVES FROM THE SAME DIRECTION. THIS WILL RESULT IN HIGHER
BREAKERS AND COASTAL RUN UP FOR ABOUT 24 HOURS. ANOTHER SET OF
WEAK NELY SWELLS FOR THURSDAY BEFORE FIRST SIGNIFICANT NWLY SWELLS
OF THE SEASON ARRIVE EARLY THE FOLLOWING WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 87 76 / 20 20 20 20
STT 87 77 87 77 / 40 40 40 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
10/93
000
FXCA62 TJSJ 220610
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
210 AM AST SUN NOV 22 2009
.SYNOPSIS...MID LEVEL HIGH PRESSURE TO DOMINATE THROUGH THE
FORECAST PERIOD...ONLY ALLOWING FOR THE TYPICAL AFTERNOON SHOWERS
AND THUNDERSTORMS OVER WESTERN PUERTO RICO EACH AFTERNOON AND
NOCTURNAL PASSING SHOWERS OVER THE WATERS.
&&
.DISCUSSION...QUIET WEEK IN STORE AS MID LEVEL RIDGE KEEPS MID LAT
SYSTEMS MAINLY NORTH AND TROPICAL WEATHER TO OUR SOUTH NEXT 7
DAYS. SURFACE PRESSURE GRADIENT TO RETURN TO NORMAL TODAY OR
TOMORROW ALLOWING FOR WINDS TO RETURN BACK TO CLIMO DIRECTION AND
SPEED. VERY SIMPLE DIURNAL CONVECTIVE FORECAST FOR THE NEXT 7
DAYS. BY NEXT WEEKEND GFS SHOWS A POLAR FRONTAL PASSAGE OVER THE
LOCAL AREA...BUT RECENT RUNS HAVE SLOWED TIMING. UPDATED GRIDS TO
REFLECT THE CHANGE.
&&
.AVIATION...VFR ALL SITES EXCEPT TJMZ AND TJBQ WHERE MVFR TO IFR
TEMPO CONDS POSSIBLE 18Z-22Z.
&&
.MARINE...WEAK NORTHEASTERLY SWELL ENERGY TO PERSIST THROUGH
MONDAY AFTERNOON WHEN MUCH LONGER PERIOD ENERGY (12-14 SECONDS)
ARRIVES FROM THE SAME DIRECTION. THIS WILL RESULT IN HIGHER
BREAKERS AND COASTAL RUN UP FOR ABOUT 24 HOURS. ANOTHER SET OF
WEAK NELY SWELLS FOR THURSDAY BEFORE FIRST SIGNIFICANT NWLY SWELLS
OF THE SEASON ARRIVE EARLY THE FOLLOWING WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 87 76 / 20 20 20 20
STT 87 77 87 77 / 40 40 40 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
10/93
000
FXCA62 TJSJ 220241 AAA
AFDSJU
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1041 PM AST SAT NOV 21 2009
.UPDATE...EXPECT CLEAR TO PARTLY CLOUDY SKIES ACROSS THE LOCAL
ISLANDS OVERNIGHT. ISOLATED TO SCATTERED SHOWERS ARE EXPECTED...
MAINLY OVER THE U.S. VIRGIN ISLANDS...CULEBRA AND VIEQUES AND THE
EASTERN THIRD OF PUERTO RICO...AS WELL AS ACROSS THE COASTAL
WATERS WHERE AN ISOLATED THUNDERSTORM OR TWO COULD ALSO OCCUR.
INHERITED SHORT TERM GRIDS AND ZFP HAD A GOOD HANDLE ON EXPECTED
CONDITIONS OVERNIGHT AND DID NOT SEND A ZFP UPDATE. FOR THE
COASTAL WATERS...MADE A COUPLE OF MINOR ALTERATIONS TO THE
PREVIOUS CWF...MAINLY TO THE SYNOPSIS...OTHERWISE NO CHANGES./ BCS
&&
.AVIATION...PREVAILING VFR CONDITIONS WILL CONTINUE ACROSS THE
LOCAL ISLANDS AND AT ALL LOCAL TAF SITES OVERNIGHT. HOWEVER...
BRIEF MVFR CONDITIONS ARE EXPECTED IN SCATTERED PASSING SHRA AND
ISOLATED TSRA. ALSO...VOLCANIC ASH AND STEAM FROM MONTSERRAT WILL
MOVE WEST NORTHWEST OR WEST OVERNIGHT AND SHOULD REMAIN MAINLY
SOUTH OF THE LOCAL ISLANDS. PLEASE REFER TO SIGMET JULIETT 2./ BCS
REMAINDER BELOW UNCHANGED FROM THE DAY SHIFT.
&&
.PREV DISCUSSION... /ISSUED 352 PM AST SAT NOV 21 2009/
SYNOPSIS...LOCALLY DRIVEN SHOWERS AND ISOLATED THUNDERSTORMS WILL
DOMINATE THE WEATHER ACROSS PUERTO RICO AND THE U.S VIRGIN
ISLANDS FOR THE NEXT SEVERAL DAYS.
DISCUSSION...THE SURGE IN MOISTURE ENTERING THE EASTERN CARIBBEAN
THIS AFTERNOON IS EXPECTED TO REMAIN MAINLY SOUTH OF THE LOCAL
ISLANDS AS IT PASSES BY OVERNIGHT AND ON SUNDAY. EVEN SO...MAY SEE
AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY OVER THE LOCAL
CARIBBEAN WATERS...HOWEVER...WEATHER ACROSS PUERTO RICO AND THE
U.S. VIRGIN ISLANDS IS EXPECTED TO REMAIN MAINLY DIURNAL DRIVEN
IN NATURE. WHILE RIDGING IS EXPECTED TO DOMINATE THE MID TO UPPER
LEVELS OF THE ATMOSPHERE OVER THE NEXT WEEK...EXPECT SOME SHOWER
DEVELOPMENT OVER THE INTERIOR OF THE ISLAND EACH DAY...AS
SUFFICIENT LOW LEVEL MOISTURE AND DAYTIME HEATING SHOULD PROVIDE
ENOUGH OF A TRIGGER FOR SOME SHOWER ACTIVITY. NO LARGE SCALE
WEATHER FEATURES ARE EXPECTED TO IMPACT THE LOCAL AREA THROUGH THE
END OF THE FORECAST PERIOD.
AVIATION...PERIODS OF MVFR AND BRIEF IFR CONDS WILL REMAIN POSSIBLE
ACROSS TJSJ...TJBQ AND TJMZ THROUGH 21/22Z...WITH VFR CONDS EXPECTED
AT THE REST OF LOCAL TAF SITES. THEREAFTER...PREVAILING VFR FORECAST
FOR THE ENTIRE FLYING AREA OVERNIGHT AT LEAST THROUGH 22/04Z...
FOLLOWED BY PROB30 OF PASSING SHRA IN AND AROUND TJSJ... TISX...
TIST...TNCM...AND TKPK FM 22/04Z-22/06Z. ELSEWHERE...VA EMISSIONS
CONTINUE FM TRPG...WITH LOW TO MID LEVEL STEERING FROM THE EAST
SOUTHEAST DURG THE NEXT 24 HRS. BASED ON LATEST SATELLITE IMAGERY...
FAINT ASH AN GAS EMISSIONS ARE STILL EXPECTED TO REMAIN OVR WATER
JUST EAST NORTHEAST OF THE TIST AIRDROME BTW TIST AND TUPJ.
CLIMATE...THE HIGH TEMPERATURE REACHED 91 DEGREES AT THE LUIS
MUNOZ INTERNATIONAL AIRPORT IN SAN JUAN TODAY. THIS BROKE THE
PREVIOUS HIGH TEMPERATURE FOR NOVEMBER 21ST...WHICH REACH 90
DEGREES BACK IN 2006.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 76 87 / 40 40 40 40
STT 78 87 77 87 / 40 50 40 40
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
000
FXCA62 TJSJ 211952
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
352 PM AST SAT NOV 21 2009
.SYNOPSIS...LOCALLY DRIVEN SHOWERS AND ISOLATED THUNDERSTORMS WILL
DOMINATE THE WEATHER ACROSS PUERTO RICO AND THE U.S VIRGIN
ISLANDS FOR THE NEXT SEVERAL DAYS.
&&
.DISCUSSION...THE SURGE IN MOISTURE ENTERING THE EASTERN CARIBBEAN
THIS AFTERNOON IS EXPECTED TO REMAIN MAINLY SOUTH OF THE LOCAL
ISLANDS AS IT PASSES BY OVERNIGHT AND ON SUNDAY. EVEN SO...MAY SEE
AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY OVER THE LOCAL
CARIBBEAN WATERS...HOWEVER...WEATHER ACROSS PUERTO RICO AND THE
U.S. VIRGIN ISLANDS IS EXPECTED TO REMAIN MAINLY DIURNAL DRIVEN
IN NATURE. WHILE RIDGING IS EXPECTED TO DOMINATE THE MID TO UPPER
LEVELS OF THE ATMOSPHERE OVER THE NEXT WEEK...EXPECT SOME SHOWER
DEVELOPMENT OVER THE INTERIOR OF THE ISLAND EACH DAY...AS
SUFFICIENT LOW LEVEL MOISTURE AND DAYTIME HEATING SHOULD PROVIDE
ENOUGH OF A TRIGGER FOR SOME SHOWER ACTIVITY. NO LARGE SCALE
WEATHER FEATURES ARE EXPECTED TO IMPACT THE LOCAL AREA THROUGH THE
END OF THE FORECAST PERIOD.
&&
.AVIATION...PERIODS OF MVFR AND BRIEF IFR CONDS WILL REMAIN POSSIBLE
ACROSS TJSJ...TJBQ AND TJMZ THROUGH 21/22Z...WITH VFR CONDS EXPECTED
AT THE REST OF LOCAL TAF SITES. THEREAFTER...PREVAILING VFR FORECAST
FOR THE ENTIRE FLYING AREA OVERNIGHT AT LEAST THROUGH 22/04Z...
FOLLOWED BY PROB30 OF PASSING SHRA IN AND AROUND TJSJ... TISX...
TIST...TNCM...AND TKPK FM 22/04Z-22/06Z. ELSEWHERE...VA EMISSIONS
CONTINUE FM TRPG...WITH LOW TO MID LEVEL STEERING FROM THE EAST
SOUTHEAST DURG THE NEXT 24 HRS. BASED ON LATEST SATELLITE IMAGERY...
FAINT ASH AN GAS EMISSIONS ARE STILL EXPECTED TO REMAIN OVR WATER
JUST EAST NORTHEAST OF THE TIST AIRDROME BTW TIST AND TUPJ.
&&
.CLIMATE...THE HIGH TEMPERATURE REACHED 91 DEGREES AT THE LUIS
MUNOZ INTERNATIONAL AIRPORT IN SAN JUAN TODAY. THIS BROKE THE
PREVIOUS HIGH TEMPERATURE FOR NOVEMBER 21ST...WHICH REACH 90
DEGREES BACK IN 2006.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 76 87 / 40 40 40 40
STT 78 87 77 87 / 40 50 40 40
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
09/04
000
FXCA62 TJSJ 211501
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1101 AM AST SAT NOV 21 2009
.UPDATE...
MADE MINOR ADJUSTMENTS TO SHORT TERM WIND FLOW BUT OVERALL NO
CHANGES TO THE INHERITED FORECAST. CLOUDS HAVE BEGUN TO SLOWLY
DEVELOP ACROSS THE INTERIOR SECTIONS OF PUERTO RICO...BUT SO FAR
NO SHOWERS ACTIVITY DETECTED AT THIS TIME. AFTERNOON CONVECTION
WILL AGAIN BE FOCUSED ACROSS PARTS OF THE INTERIOR NORTHWEST AND
NORTH CENTRAL SECTIONS OF THE ISLAND...WITH GRADUAL A DIMINISHING
AND DISSIPATION OF ACTIVITY AFTER SUNSET.
&&
.AVIATION UPDATE...STILL EXPCT MVFR/IFR CONDS IN SHRA/TSRA BTWN
21/18-21Z AT TJBQ...AND VCTY TJMZ. ACTIVITY LESS LIKELY OVER MUCH
OF SAN JUAN METRO AREA TODAY...HOWEVER ONE OR TWO CU LINES MAY DEVELOP
OVR EL YUNQUE AND STREAM NORTHWEST VCTY TJSJ PRODUCING BRIEF VCSH
PSBL BTW 21/18-21Z SHRA. ELSEWHERE AND OUTSIDE OF THE FLYING AREA....VA
EMISSIONS CONTINUE OFF AND ON FROM MONTSERRAT/TRPG AND FAINT PLUME VISIBLE
STREAMING SOME 100 MILES OR SO NW OF TKPK BUT BCMG LESS VISIBLE AS IT
MOVES AWAY FROM SOURCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 86 76 / 40 40 40 40
STT 87 78 87 77 / 50 50 50 40
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
09/04
000
FXCA62 TJSJ 210833
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
433 AM AST SAT NOV 21 2009
.SYNOPSIS...AN UPPER MID-UPPER LEVEL SUBTROPICAL RIDGE WILL BUILD
NORTHWARDS ACROSS THE REGION...AND REMAIN IN PLACE OVER THE NEXT
FEW DAYS. THIS WILL RESULT IN OVERALL UPPER LEVEL CONVERGENCE AND
MOSTLY SUBSIDENT PATTERN THE NEXT FEW DAYS. AN EASTERLY PERTURBATION
AND ASSOCIATED MOISTURE LOCATED EAST OF THE LESSER ANTILLES WILL
ENTER THE EASTERN CARIBBEAN LATER TODAY AND APPROACH THE LOCAL AREA BY
SUNDAY.
&&
.DISCUSSION...THE LOCAL DOPPLER CONTINUE TO SHOW ISOLATED TO
SCATTERED SHOWERS MOVING ACROSS THE LOCAL WATERS THIS MORNING...
WITH A FEW AFFECTING THE EASTERN PORTIONS OF PUERTO RICO.
ALTHOUGH UPPER LEVEL CONDITIONS ARE NOT FAVORABLE THUNDERSTORMS
DEVELOPMENT...ENOUGH SOLAR HEATING AND LOCAL EFFECT WILL COMBINE
WITH LINGERING MOISTURE THIS AFTERNOON TO GENERATE ISOLATED TO
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE INTERIOR
SECTION AND NORTHWEST PORTIONS OF PUERTO RICO. CU LINES WILL ALSO
DEVELOP OVER EL YUNQUE AND LOCAL ISLANDS.
LOW LEVEL PERTURBATION NOW LOCATED OVER THE LESSER ANTILLES WILL
CONTINUE TO MOVE WEST AND APPROACH THE LOCAL AREA ON SUNDAY. THIS
WILL BRING AN INFLUX OF TROPICAL MOISTURE ACROSS THE REGION AND
THUS INCREASE THE CHANCES FOR SHOWERS AND THUNDERSTORM ACTIVITY
ACROSS THE LOCAL ISLANDS AND SURROUNDING WATERS.
&&
.AVIATION...TEMPO IFR CONDS IN TSRA EXPECTED THIS AFTERNOON 19-21Z
TJBQ...AND SLIGHTLY LESS LIKELY OVER TJSJ. VA EMISSIONS CONTINUE OFF
AND ON FROM MONTSERRAT BUT SHOULD REMAIN JUST SOUTH OF TKPK THROUGH
THE MORNING...AND AWAY FROM ALL OTHER SITES.
&&
.MARINE...MARINE CONDITIONS WILL BEGIN TO CHANGE TODAY AS WINDS
WILL START TO PICK UP THROUGH TONIGHT...THIS WILL RESULT ON A
MODERATE CHOPPY CONDITIONS ACROSS THE LOCAL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 86 76 / 40 40 40 40
STT 87 78 87 77 / 50 50 50 40
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
93/10
000
FXCA62 TJSJ 210242 AAA
AFDSJU
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1042 PM AST FRI NOV 20 2009
.UPDATE...EXPECT CLEAR TO PARTLY CLOUDY SKIES ACROSS THE LOCAL
ISLANDS OVERNIGHT. ISOLATED TO LOCALLY SCATTERED SHOWERS ARE
EXPECTED...MAINLY OVER THE U.S. VIRGIN ISLANDS...CULEBRA AND
VIEQUES AND THE EASTERN THIRD OF PUERTO RICO...AS WELL AS ACROSS
THE COASTAL WATERS WHERE AN ISOLATED THUNDERSTORM OR TWO COULD
ALSO OCCUR. INHERITED SHORT TERM GRIDS AND ZFP HAD A GOOD HANDLE
ON EXPECTED CONDITIONS OVERNIGHT AND DID NOT SEND A ZFP UPDATE.
FOR THE COASTAL WATERS...MADE A COUPLE OF SEMANTIC ALTERATIONS
TO THE PREVIOUS CWF...MAINLY TO THE SYNOPSIS...OTHERWISE NO
CHANGES./ BCS
&&
.AVIATION...PREVAILING VFR CONDITIONS WILL CONTINUE ACROSS THE
LOCAL ISLANDS AND AT ALL LOCAL TAF SITES OVERNIGHT. HOWEVER...
BRIEF MVFR CONDITIONS ARE EXPECTED IN SCATTERED PASSING SHRA AND
ISOLATED TSRA. ALSO...ANY VOLCANIC ASH AND STEAM FROM MONTSERRAT
WILL MOVE GENERALLY WEST NORTHWEST OVERNIGHT AND SHOULD REMAIN
MAINLY SOUTH OF THE LOCAL ISLANDS./ BCS
REMAINDER BELOW UNCHANGED FROM THE DAY SHIFT.
&&
.PREV DISCUSSION... /ISSUED 310 PM AST FRI NOV 20 2009/
SYNOPSIS...
A LOW LEVEL TROUGH NOW EXTENDING ACROSS THE MONA PASSAGE WILL
CONTINUE TO MOVE WEST AND EXIT THE LOCAL AREA LATER THIS EVENING.
MEANWHILE...THE ATLANTIC HIGH PRESSURE RIDGE EXTENDS WEAKLY
SOUTHWARD ACROSS THE NORTHEAST CARIBBEAN. A WEAKENING UPPER
TROUGH/TUTT NOW NORTHEAST OF THE LOCAL AREA...WILL CONTINUE TO
LIFT FURTHER EAST WHILE THE UPPER MID-UPPER LEVEL SUBTROPICAL
RIDGE BUILDS NORTHWARDS ACROSS THE REGION...AND REMAIN IN PLACE
OVER THE NEXT FEW DAYS. THIS WILL RESULT IN OVERALL UPPER LEVEL
CONVERGENCE AND MOSTLY SUBSIDENT PATTERN THE NEXT FEW DAYS. AN
EASTERLY PERTURBATION AND ASSOCIATED MOISTURE LOCATED EAST OF THE
LESSER ANTILLES WILL ENTER THE EASTERN CARIBBEAN LATE SATURDAY AND
APPROACH THE LOCAL AREA BY SUNDAY.
DISCUSSION...
MOISTURE TRAILING THE SURFACE TROUGH ALONG WITH LOCAL AND DIURNAL
EFFECTS ONCE AGAIN INITIATED THE DEVELOPMENT OF AFTERNOON SHOWERS
AND THUNDERSTORMS MAINLY ACROSS THE NORTHERN HALF OF PUERTO RICO
TODAY. THIS ACTIVITY AND CLOUDINESS WILL DIMINISH AND DISSIPATED
AFTER SUNSET LEAVING MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
ON SATURDAY....FAIRLY STABLE UPPER LEVEL AIR MASS WILL INHIBIT AND
SIGNIFICANT DEVELOPMENT ACROSS THE ISLANDS. HOWEVER THE EXPECTED
EAST SOUTHEAST FLOW WILL CONTINUE TO BRING PATCHES OF TROPICAL
MOISTURE ACROSS THE REGION THROUGHOUT THE DAY . THIS WILL COMBINE
WITH THE LOCAL EFFECTS AND DIURNAL VARIATIONS DURING THE AFTERNOON
TO PRODUCE AREAS OF SHOWERS AND ONE OR TWO ISOLATED THUNDERSTORMS
MAINLY ACROSS THE INTERIOR AND WEST SECTIONS OF PUERTO RICO. THE
PREVAILING EAST SOUTHEAST FLOW WILL ALSO BRING PATCHES OF CLOUDS
AND PASSING SHOWERS TO THE NORTHEAST SECTION OF THE ISLANDS DURING
THE EARLY MORNING HOURS. LESSER ACTIVITY IS EXPECTED ACROSS THE
U.S VIRGIN ISLANDS ON SATURDAY.
THE ABOVE MENTIONED LOW LEVEL PERTURBATION/MOISTURE SURGE WILL MOVE
ACROSS THE EASTERN CARIBBEAN BY SATURDAY NIGHT AND APPROACH THE
LOCAL AREA ON SUNDAY. THIS WILL BRING AN INFLUX OF TROPICAL
MOISTURE ACROSS THE REGION AND THUS INCREASE THE CHANCES FOR
SHOWERS AND THUNDERSTORM ACTIVITY ACROSS THE LOCAL ISLANDS AND
SURROUNDING WATERS. THEREAFTER...AND INTO THE EARLY PART OF THE
NEXT WEEK EXPECT PREVAILING EAST NORTHEAST WIND FLOW WITH MORE OF
THE TYPICAL WEATHER PATTERN ACROSS THE REGION WITH EARLY MORNING
PASSING SHOWERS IN THE EAST... FOLLOWED BY ISOLATED AREAS OF
AFTERNOON CONVECTION IN THE WEST AND INTERIOR INTERIOR SECTIONS OF
PUERTO RICO...AND THE LEE-SIDE OF THE U.S. VIRGIN ISLANDS.
AVIATION...TEMPORARY MVFR CONDITIONS AND BRIEF IFR CONDITIONS WILL
BE POSSIBLE ACROSS TJSJ...TJBQ AND TJMZ THROUGH 23Z...WITH
PREVAILING VFR CONDITIONS EXPECTED REMAINDER OF TAF SITES. VFR
CONDITIONS THEN EXPECTED ACROSS ALL TAF SITES OVERNIGHT THROUGH AT
LEAST 21/16Z. IN ADDITION...WILL NEED TO CONTINUE TO MONITOR
EMISSIONS FROM MONTSERRAT...WITH ASH NEARING...BUT EXPECTED TO
REMAIN JUST SOUTH OF...TKPK AT THIS TIME.
CLIMATE...WITH THE ADDITIONAL RAINFALL RECEIVED AT THE LUIS MUNOZ
INTERNATIONAL AIRPORT TODAY...NOVEMBER 2009 IS NOW THE 4TH WETTEST
NOVEMBER ON RECORD. THE WETTEST NOVEMBER ON RECORD WAS NOVEMBER
1979...WHEN A TOTAL OF 15.96 INCHES OF RAINFALL ACCUMULATED AT THE
LUIS MUNOZ INTERNATIONAL AIRPORT IN SAN JUAN.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 74 86 76 86 / 30 40 40 40
STT 78 87 78 87 / 40 50 50 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
000
FXCA62 TJSJ 201910
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
310 PM AST FRI NOV 20 2009
.SYNOPSIS...
A LOW LEVEL TROUGH NOW EXTENDING ACROSS THE MONA PASSAGE WILL
CONTINUE TO MOVE WEST AND EXIT THE LOCAL AREA LATER THIS EVENING.
MEANWHILE...THE ATLANTIC HIGH PRESSURE RIDGE EXTENDS WEAKLY SOUTHWARD
ACROSS THE NORTHEAST CARIBBEAN. A WEAKENING UPPER TROUGH/TUTT NOW
NORTHEAST OF THE LOCAL AREA...WILL CONTINUE TO LIFT FURTHER EAST WHILE
THE UPPER MID-UPPER LEVEL SUBTROPICAL RIDGE BUILDS NORTHWARDS ACROSS
THE REGION...AND REMAIN IN PLACE OVER THE NEXT FEW DAYS. THIS WILL
RESULT IN OVERALL UPPER LEVEL CONVERGENCE AND MOSTLY SUBSIDENT PATTERN
THE NEXT FEW DAYS. AN EASTERLY PERTURBATION AND ASSOCIATED MOISTURE
LOCATED EAST OF THE LESSER ANTILLES WILL ENTER THE EASTERN CARIBBEAN
LATE SATURDAY AND APPROACH THE LOCAL AREA BY SUNDAY.
&&
.DISCUSSION...
MOISTURE TRAILING THE SURFACE TROUGH ALONG WITH LOCAL AND DIURNAL
EFFECTS ONCE AGAIN INITIATED THE DEVELOPMENT OF AFTERNOON SHOWERS
AND THUNDERSTORMS MAINLY ACROSS THE NORTHERN HALF OF PUERTO RICO
TODAY. THIS ACTIVITY AND CLOUDINESS WILL DIMINISH AND DISSIPATED
AFTER SUNSET LEAVING MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
ON SATURDAY....FAIRLY STABLE UPPER LEVEL AIRMASS WILL INHIBIT AND
SIGNIFICANT DEVELOPMENT ACROSS THE ISLANDS. HOWEVER THE EXPECTED
EAST SOUTHEAST FLOW WILL CONTINUE TO BRING PATCHES OF TROPICAL
MOISTURE ACROSS THE REGION THROUGHOUT THE DAY . THIS WILL COMBINE
WITH THE LOCAL EFFECTS AND DIURNAL VARIATIONS DURING THE AFTERNOON
TO PRODUCE AREAS OF SHOWERS AND ONE OR TWO ISOLATED THUNDERSTORMS
MAINLY ACROSS THE INTERIOR AND WEST SECTIONS OF PUERTO RICO. THE
PREVAILING EAST SOUTHEAST FLOW WILL ALSO BRING PATCHES OF CLOUDS
AND PASSING SHOWERS TO THE NORTHEAST SECTION OF THE ISLANDS DURING
THE EARLY MORNING HOURS. LESSER ACTIVITY IS EXPECTED ACROSS THE
U.S VIRGIN ISLANDS ON SATURDAY.
THE ABOVE MENTIONED LOW LEVEL PERTURBATION/MOISTURE SURGE WILL MOVE
ACROSS THE EASTERN CARIBBEAN BY SATURDAY NIGHT AND APPROACH THE
LOCAL AREA ON SUNDAY. THIS WILL BRING AN INFLUX OF TROPICAL MOISTURE
ACROSS THE REGION AND THUS INCREASE THE CHANCES FOR SHOWERS AND
THUNDERSTORM ACTIVITY ACROSS THE LOCAL ISLANDS AND SURROUNDING WATERS.
THEREAFTER...AND INTO THE EARLY PART OF THE NEXT WEEK EXPECT PREVAILING
EAST NORTHEAST WIND FLOW WITH MORE OF THE TYPICAL WEATHER PATTERN ACROSS
THE REGION WITH EARLY MORNING PASSING SHOWERS IN THE EAST...
FOLLOWED BY ISOLATED AREAS OF AFTERNOON CONVECTION IN THE WEST AND
INTERIOR INTERIOR SECTIONS OF PUERTO RICO...AND THE LEE-SIDE OF
THE U.S. VIRGIN ISLANDS.
&&
.AVIATION...TEMPORARY MVFR CONDITIONS AND BRIEF IFR CONDITIONS WILL
BE POSSIBLE ACROSS TJSJ...TJBQ AND TJMZ THROUGH 23Z...WITH
PREVAILING VFR CONDITIONS EXPECTED REMAINDER OF TAF SITES. VFR
CONDITIONS THEN EXPECTED ACROSS ALL TAF SITES OVERNIGHT THROUGH AT
LEAST 21/16Z. IN ADDITION...WILL NEED TO CONTINUE TO MONITOR
EMISSIONS FROM MONTSERRAT...WITH ASH NEARING...BUT EXPECTED TO
REMAIN JUST SOUTH OF...TKPK AT THIS TIME.
.CLIMATE...WITH THE ADDITIONAL RAINFALL RECEIVED AT THE LUIS MUNOZ
INTERNATIONAL AIRPORT TODAY...NOVEMBER 2009 IS NOW THE 4TH WETTEST
NOVEMBER ON RECORD. THE WETTEST NOVEMBER ON RECORD WAS NOVEMBER
1979...WHEN A TOTAL OF 15.96 INCHES OF RAINFALL ACCUMULATED AT THE
LUIS MUNOZ INTERNATIONAL AIRPORT IN SAN JUAN.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 75 86 / 30 40 40 40
STT 78 87 77 87 / 40 50 50 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
04/09
000
FXCA62 TJSJ 201533
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1133 AM AST FRI NOV 20 2009
.UPDATE...WENT AHEAD AND SENT AN UPDATE TO THE FORECAST TO
INCREASE SHOWER AND THUNDERSTORM COVERAGE ACROSS SOUTHERN AND
EASTERN SECTIONS OF PR THROUGH THE EARLY AFTERNOON HOURS AS THE
PASSING LOW LEVEL TROUGH IS SPARKING QUITE A BIT OF SHOWER
ACTIVITY THIS MORNING. NO OTHER SIGNIFICANT CHANGES NECESSARY AT
THIS TIME.
&&
.AVIATION...PREVAILING VFR CONDITIONS EXPECTED ACROSS THE SMALLER
ISLANDS TODAY...WITH BRIEF MVFR CONDITIONS POSSIBLE ACROSS TJPS
THROUGH 20/17Z. AFT 20/17Z...TEMPORARY MVFR CONDITIONS WILL BE
POSSIBLE ACROSS TJMZ...TJSJ AND TJBQ...WITH A PASSING TSRA
POSSIBLY RESULTING IN BRIEF IFR CONDITIONS ACROSS THESE SITES AS
WELL. VFR CONDITIONS EXPECTED ACROSS REMAINDER OF TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 409 AM AST FRI NOV 20 2009/
SYNOPSIS...A TUTT WILL CONTINUE TO MOVE EAST NORTHEAST...AWAY FROM
THE LOCAL ISLANDS AND WEAKENED THIS MORNING...HAVING LESS INFLUENCE
ON THE LOCAL WEATHER CONDITIONS. A MID LEVEL HIGH PRESSURE ACROSS
THE SOUTHWESTERN CARIBBEAN HAVE ALREADY START TO BUILD ACROSS THE
LOCAL ISLANDS...LIMITING THE SHOWER ACTIVITY ACROSS THE LOCAL
FORECAST AREA. MOISTURE WILL INCREASE FROM THE SOUTHEAST BY THE
UPCOMING WEEKEND...INCREASING THE CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS THE REGION.
DISCUSSION...SATELLITE AND RADAR IMAGES ARE STILL SHOWING LARGE
AMOUNT OF RAINFALL ACTIVITY ACROSS THE LOCAL WATERS...MAINLY
ACROSS THE ATLANTIC WATERS. THIS AREA LOW LEVEL MOISTURE WILL
CONTINUE TO MOVE WEST AND AWAY FROM THE LOCAL WATERS LATER THIS
MORNING. ALTHOUGH UPPER CONDITIONS ARE NOT FAVORABLE FOR SHOWERS
AND THUNDERSTORMS ENHANCEMENT...LINGERING MOISTURE AND LOCAL
EFFECTS WILL HELP DEVELOP AFTERNOON SHOWERS AND THUNDERSTORMS
ACROSS THE INTERIOR AND NORTHWEST PORTIONS OF PUERTO RICO. ALSO A
CU LINE COULD DEVELOP OVER EL YUNQUE AND AFFECT THE SAN JUAN
METROPOLITAN AREA. THE U.S. VIRGIN ISLANDS COULD ALSO EXPERIENCE
SHOWERS IN THE FORM OF CU LINES.
A LOW LEVEL TROUGH NOW LOCATED JUST EAST OF THE LESSER ANTILLES
WILL CONTINUE TO MOVE WEST AND ACROSS THE CARIBBEAN WATERS.
ALTHOUGH MOST OF THE MOISTURE WILL REMAIN WELL SOUTH OF THE
ISLAND ENOUGH MOISTURE WILL BE AVAILABLE TO INCREASE CLOUD AND
SHOWER COVERAGE ACROSS THE LOCAL FORECAST AREA.
AVIATION...VFR CONDITIONS ARE EXPECTED ACROSS ALL TAF SITES DURING
THE MORNING HOURS. VCSH ARE POSSIBLE ACROSS TISX...AND TIST AT LEAST
THROUGH 20/16Z. AFTER 20/16Z..MVFR CONDITIONS WITH MOUNTAIN
OBSCURATIONS ARE POSSIBLE ACROSS TJBQ...AND TJMZ AS SHOWERS WITH
ISOLATED THUNDERSTORMS DEVELOP ACROSS THE CORDILLERA CENTRAL.
ALSO...TJSJ COULD SEE BRIEF PERIODS OF MVFR CONDITIONS FROM 20/19Z
THROUGH 20/22Z.
MARINE...MARINE CONDITIONS WILL REMAIN TRANQUIL THROUGH AT LEAST
SATURDAY...WHEN WINDS ARE EXPECTED TO SLIGHTLY INCREASE...ENOUGH
TO GENERATE A SMALL CHOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 87 75 / 30 30 40 50
STT 87 78 87 77 / 30 40 60 60
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
04/09
000
FXCA62 TJSJ 200809
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
409 AM AST FRI NOV 20 2009
.SYNOPSIS...A TUTT WILL CONTINUE TO MOVE EAST NORTHEAST...AWAY FROM
THE LOCAL ISLANDS AND WEAKENED THIS MORNING...HAVING LESS INFLUENCE
ON THE LOCAL WEATHER CONDITIONS. A MID LEVEL HIGH PRESSURE ACROSS
THE SOUTHWESTERN CARIBBEAN HAVE ALREADY START TO BUILD ACROSS THE
LOCAL ISLANDS...LIMITING THE SHOWER ACTIVITY ACROSS THE LOCAL
FORECAST AREA. MOISTURE WILL INCREASE FROM THE SOUTHEAST BY THE
UPCOMING WEEKEND...INCREASING THE CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS THE REGION.
&&
.DISCUSSION...SATELLITE AND RADAR IMAGES ARE STILL SHOWING LARGE
AMOUNT OF RAINFALL ACTIVITY ACROSS THE LOCAL WATERS...MAINLY
ACROSS THE ATLANTIC WATERS. THIS AREA LOW LEVEL MOISTURE WILL
CONTINUE TO MOVE WEST AND AWAY FROM THE LOCAL WATERS LATER THIS
MORNING. ALTHOUGH UPPER CONDITIONS ARE NOT FAVORABLE FOR SHOWERS
AND THUNDERSTORMS ENHANCEMENT...LINGERING MOISTURE AND LOCAL
EFFECTS WILL HELP DEVELOP AFTERNOON SHOWERS AND THUNDERSTORMS
ACROSS THE INTERIOR AND NORTHWEST PORTIONS OF PUERTO RICO. ALSO A
CU LINE COULD DEVELOP OVER EL YUNQUE AND AFFECT THE SAN JUAN
METROPOLITAN AREA. THE U.S. VIRGIN ISLANDS COULD ALSO EXPERIENCE
SHOWERS IN THE FORM OF CU LINES.
A LOW LEVEL TROUGH NOW LOCATED JUST EAST OF THE LESSER ANTILLES
WILL CONTINUE TO MOVE WEST AND ACROSS THE CARIBBEAN WATERS.
ALTHOUGH MOST OF THE MOISTURE WILL REMAIN WELL SOUTH OF THE
ISLAND ENOUGH MOISTURE WILL BE AVAILABLE TO INCREASE CLOUD AND
SHOWER COVERAGE ACROSS THE LOCAL FORECAST AREA.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED ACROSS ALL TAF SITES DURING
THE MORNING HOURS. VCSH ARE POSSIBLE ACROSS TISX...AND TIST AT LEAST
THROUGH 20/16Z. AFTER 20/16Z..MVFR CONDITIONS WITH MOUNTAIN
OBSCURATIONS ARE POSSIBLE ACROSS TJBQ...AND TJMZ AS SHOWERS WITH
ISOLATED THUNDERSTORMS DEVELOP ACROSS THE CORDILLERA CENTRAL.
ALSO...TJSJ COULD SEE BRIEF PERIODS OF MVFR CONDITIONS FROM 20/19Z
THROUGH 20/22Z.
&&
.MARINE...MARINE CONDITIONS WILL REMAIN TRANQUIL THROUGH AT LEAST
SATURDAY...WHEN WINDS ARE EXPECTED TO SLIGHTLY INCREASE...ENOUGH
TO GENERATE A SMALL CHOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 75 86 / 40 40 50 50
STT 78 87 77 87 / 60 60 60 60
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
93/10
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