FXCA62 TJSJ 260944
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
544 AM AST THU NOV 26 2009
.SYNOPSIS...PATCHY LOW LEVEL MOISTURE WILL RESULT IN VARIABLY
CLOUDY SKIES AND SCATTERED SHOWERS ACROSS MUCH NORTHERN PUERTO AND
THE U.S. VIRGIN ISLANDS TODAY...WITH AN ISOLATED THUNDERSTORM OR
TWO POSSIBLE ACROSS THE WESTERN INTERIOR AND WESTERN SECTIONS OF
PUERTO RICO THIS AFTERNOON. 
&&
.DISCUSSION...WHILE HIGH PRESSURE IS EXPECTED TO PERSIST ACROSS
THE MID TO UPPER LEVELS OF THE ATMOSPHERE THROUGH THE UPCOMING
WEEKEND...EXPECT CONTINUED PERIODS OF SHALLOW MOISTURE TO STEER
OCCASIONAL CLOUDS AND SHOWERS ACROSS THE LOCAL ISLANDS FOR THE
NEXT SEVERAL DAYS...WITH ONLY THE VERY ISOLATED CHANCE FOR A
THUNDERSTORM OVER THE WESTERN INTERIOR AND WESTERN SECTIONS OF
PUERTO RICO EACH AFTERNOON. 
AN APPROACHING FRONTAL BOUNDARY...CURRENTLY ACROSS THE SOUTHERN TIP
OF FLORIDA...WILL LIKELY STALL WELL NORTH OF THE LOCAL ISLANDS ON
SATURDAY AND SUNDAY...WITH ITS REMNANTS GETTING PUSHED ACROSS THE
AREA EARLY NEXT WEEK...AS THE MID TO UPPER LEVEL HIGH PRESSURE RIDGE
BREAKS DOWN AND AN UPPER LEVEL DISTURBANCE RACES BY. IF THIS PANS
OUT...WILL LIKELY SEE A SLIGHT INCREASE IN SHOWER ACTIVITY MONDAY
AND TUESDAY...WITH STABLE ATMOSPHERIC CONDITIONS RETURNING RAPIDLY
THEREAFTER. HOWEVER...DUE TO UNCERTAINTY IN COMPUTER MODEL
GUIDANCE...HELD OFF ON ANY SIGNIFICANT CHANGES TO INHERITED
FORECAST AS TYPICAL NOCTURNAL/DIURNAL PATTERN SEEMS REASONABLE. MAIN
CONCERN CONTINUES TO BE INCREASINGLY DANGEROUS SURF CONDITIONS
EXPECTED ACROSS THE LOCAL WATERS TODAY...WITH A HIGH SURF ADVISORY
NOW IN EFFECT FROM 6 AM AST THROUGH SATURDAY MORNING.
&&
.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL 
ISLANDS AND AT ALL LOCAL TAF SITES TODAY THROUGH TONIGHT. HOWEVER... 
BRIEF MVFR CONDITIONS AND LOCAL MOUNTAIN OBSCURATIONS ARE EXPECTED 
IN PASSING SHRA AND ISOLATED TSRA...MAINLY OVER THE CENTRAL AND 
WESTERN INTERIOR AND WEST SECTIONS OF PUERTO RICO BETWEEN 25/17Z AND 
25/21Z. PLUME OF ASH AND STEAM FROM MONTSERRAT SHOULD REMAIN MAINLY
SOUTH OF THE LOCAL ISLANDS AGAIN TODAY.
&&
.MARINE...BUOY 41043 HAS BEEN DETECTING 6 TO 7 FOOT SWELLS
OVERNIGHT. WHILE THESE SWELLS WILL DIMINISH SOMEWHAT AS THEY CROSS OUR
LOCAL WATERS...THEY ARE RUNNING MODERATELY HIGHER THAN MODEL
GUIDANCE...AND WILL LIKELY RESULT IN LARGE BREAKING WAVES ALONG
THE NORTHERN EXPOSED SHOALS...REEFS AND COASTLINES OF THE LOCAL
ISLANDS TODAY AND FRIDAY. WHILE THIS IS ONLY A BORDERLINE HIGH
SURF EVENT...DUE TO THE HOLIDAY...DECIDED TO GO AHEAD AN ISSUE A
HIGH SURF ADVISORY FOR THE NORTHERN EXPOSED COASTLINES OF MAINLAND
PR...CULEBRA AND THE NORTHERN U.S. VIRGIN ISLANDS...EFFECTIVE AT 6
AM AST THIS MORNING.
&&
.CLIMATE...WITH AN ADDITIONAL THIRTY NINE HUNDREDTHS OF AN
INCH...NOVEMBER 2009 WILL MOVE INTO SECOND PLACE AS FAR AS THE
WETTEST NOVEMBERS GO. THE ALL TIME RECORD WET NOVEMBER WAS
1979...WHEN A TOTAL OF 15.96 INCHES OF RAINFALL ACCUMULATED AT THE
LUIS MUNOZ INTERNATIONAL AIRPORT IN SAN JUAN. SO FAR...12.06
INCHES OF RAIN HAS ACCUMULATED THIS MONTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU  86  73  86  73 /  30  20  20  20 
STT  86  76  85  75 /  40  20  20  20 
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...HIGH SURF ADVISORY UNTIL 10 AM AST SATURDAY FOR CULEBRA-MAYAGUEZ 
     AND VICINITY-NORTH CENTRAL-NORTHEAST-NORTHWEST-SAN JUAN AND 
     VICINITY.
VI...HIGH SURF ADVISORY UNTIL 10 AM AST SATURDAY FOR ST. THOMAS/ST. 
     JOHN/ADJACENT ISLANDS.
&&
$$
06/04