





Good morning. Yes,another round of rain is expected from now thru the weekend for the Eastern Caribbean on top from what has fallen in the past two weeks,so watch for local floodings and mudslides.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
614 AM AST THU DEC 8 2011
.SYNOPSIS...UPPER LEVEL TROUGH REMAINS ACROSS THE NORTHEASTERN
CARIBBEAN AND WILL HELP MAINTAIN UNSTABLE CONDITIONS ACROSS THE
LOCAL AREA TODAY AS IT SLOWLY LIFTS TO THE NORTHEAST. SURFACE
TROUGH EAST OF THE LEEWARD ISLANDS IS NOW MOVING WEST AND WILL
BRING ABUNDANT MOISTURE FOR THE WEEKEND. IN ADDITION...THE
PRESSURE GRADIENT WILL TIGHTEN OVER THE AREA ON FRIDAY AND
SATURDAY...INCREASING THE WINDS OVER THE LOCAL AREA. AFTERNOON
CONVECTION IS POSSIBLE TODAY ACROSS THE SOUTHERN AND WESTERN
PORTIONS OF PUERTO RICO AS THE MARGINALLY UNSTABLE ATMOSPHERE
COMBINES WITH SEA BREEZE CONVERGENCE...LOCAL EFFECTS...AVAILABLE
MOISTURE...AND DIVERGENCE IN THE UPPER LEVELS AS FORECAST BY THE
NAM MODEL.
&&
.DISCUSSION...EVEN THOUGH THE ATMOSPHERE IS MARGINALLY UNSTABLE
AND THE AVAILABLE MOISTURE IS CONCENTRATED IN THE LOWER TO MID
LEVELS OF THE ATMOSPHERE...SHOWERS AND THUNDERSTORMS MAY DEVELOP
TODAY GIVEN THE COMBINATION OF THE AFOREMENTIONED FACTORS. SOME OF
THE SHOWERS MAY HAVE MODERATE TO LOCALLY HEAVY DOWNPOURS. THIS
GENERAL PATTERN OF UNSETTLED WEATHER MAY CONTINUE THROUGH THE
WEEKEND. HOWEVER...THE GFS BRINGS A SURFACE TROUGH OVER THE AREA
ON SATURDAY AND INTO SUNDAY...SIGNIFICANTLY INCREASING AVAILABLE
MOISTURE AND THETA E AT THE LOWER LEVELS. PRECIPITABLE WATER VALUES
ARE FORECAST BY THE GFS TO EXCEED 2 INCHES BUT AT THE SAME
TIME...CONVECTIVE AVAILABLE POTENTIAL ENERGY SEEMS TO BE A BIT LOW
BY HAVING IT FORECAST TO BE AROUND 1000 J/KG AND THE LIFTED INDEX
VALUE AT -2 TO -3. RIGHT NOW IT LOOKS LIKE THIS SURFACE TROUGH
WILL BRING A GOOD DEAL OF CLOUDINESS AND SHOWERS FOR THE
WEEKEND...BUT CONVECTION MAY BE LIMITED TO AREAS WITH LESS CLOUD
COVERAGE GIVEN THE LIMITED AMOUNT OF CAPE EXPECTED BY THE GFS.
&&
.AVIATION...VFR CONDS WILL PREVAIL AT ALL TAF SITES THIS MORNING.
HOWEVER... INTERVALS OF LOW LEVEL CLDS AND PASSING SHRA WILL
AFFECT THE FOLLOWING TAF SITES WITH VERY BRIEF PERIODS OF MVFR
CONDITIONS...TJSJ...TJBQ...TIST...TISX...TNCM...TKPK. THROUGH 15Z.
ISOLATED THUNDERSTORM POSSIBLE THIS AFTERNOON IN THE VICINITY OF
TJMZ AND TJPS WITH BRIEF PERIOD OF IFR IN THE VICINITY OF THESE
SITES.
&&
.MARINE...SEAS CONTINUE TO REMAIN HAZARDOUS ACROSS THE LOCAL
WATERS. BUOY 41043 IS REPORTING WAVE HEIGHTS OF 9 FEET WITH A 10
SECOND PERIOD...WHILE BUOY 41053 IS REPORTING WAVE HEIGHTS OF 7
FEET AT A 12 SECOND PERIOD. THEREFORE...THE SMALL CRAFT ADVISORY
WAS EXTENDED UNTIL LATE FRIDAY AND THE HIGH SURF ADVISORY REMAINS
IN EFFECT UNTIL 10 AM AST TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 84 74 84 74 / 50 40 40 30
STT 85 76 86 76 / 40 40 40 30