000
FXCA62 TJSJ 020929
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
529 AM AST SUN MAY 2 2010
.SYNOPSIS...AT UPPER LEVELS...A CUT-OFF LOW WILL FORM IN A DIGGING
TROUGH...EXTENDING SOUTHWEST THROUGH THE MONA PASSAGE INTO THE
CARIBBEAN...AND MOVE RAPIDLY SOUTHWEST MONDAY AND THEN WEST ON
TUESDAY BEFORE CROSSING CUBA AND BEING ABSORBED INTO ANOTHER
TROUGH ON THURSDAY. HIGH PRESSURE WILL BUILD OVER THE EASTERN
CARIBBEAN ON TUESDAY AND EXTEND NORTH OVER PUERTO RICO ON
WEDNESDAY. IT WILL MOVE OVER THE U.S. VIRGIN ISLANDS ON THURSDAY
NIGHT AND INTO THE TROPICAL ATLANTIC ON SATURDAY. ON SATURDAY A
TROUGH AT FLORIDA'S LATITUDE WILL PASS NORTH OF THE AREA WITH
ANOTHER SHORT WAVE CROSSING THE LOCAL ISLANDS ON MONDAY.
AT MID LEVELS...HIGH PRESSURE OVER CUBA WILL GIVE WAY TO THE WEAK CUT-
OFF LOW THAT MOVES INTO THE CARIBBEAN FROM THE NORTHEAST ON MONDAY
AND WILL RIDGE OVER FLORIDA TUESDAY. THE RIDGE WILL CONTINUE EAST
ON TUESDAY AND WEDNESDAY WHILE A LOW FORMS IN THE TROPICAL
ATLANTIC EAST OF THE WINDWARD ISLANDS. THE LOW WILL MOVE SLOWLY TO
THE NORTHEAST DURING THE REST OF THE WEEK WHILE HIGH PRESSURE
WRAPS AROUND IT. SOUTHWEST FLOW OVER THE LOCAL AREA WILL COMMENCE
LATE IN THE WEEK AS A TROUGH DIGS INTO THE NORTHWESTERN CARIBBEAN.
AT LOWER LEVELS...HIGH PRESSURE WILL REMAIN IN PLACE NORTH OF
PUERTO RICO THROUGH WEDNESDAY NIGHT NEAR 28 NORTH LATITUDE. A
FRONTAL BOUNDARY WILL ALSO SAG SOUTH TODAY...REFORM ON MONDAY
TO THE NORTH AND PASS THROUGH THE AREA AGAIN ON TUESDAY BEFORE DRY
AIR IS USHERED IN ON THURSDAY. A TROUGH WILL MOVE INTO THE AREA
FROM THE EAST AND BRING MOISTURE BACK TO THE AREA ON FRIDAY AND
SATURDAY OF THE UPCOMING WEEK. ALTHOUGH THE HIGH PRESSURE BREAKS
OUT OF ITS LOCK ON THURSDAY AND BUILDS INTO THE CENTRAL ATLANTIC
BY SATURDAY...THE LOCAL AREA NEVER BREAKS FREE OF THE RIDGE THAT
EXTENDS WEST AND CROSSES FLORIDA WHICH MAINTAINS THE EASTERLY
TRADE WIND FLOW OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS.
&&
.DISCUSSION...CONSIDERABLE SHOWER ACTIVITY DEVELOPED JUST NORTH OF
PUERTO RICO...CULEBRA...SAINT THOMAS AND SAINT JOHN AND SETTLED
SOUTH OVER THE ISLANDS EARLY THIS MORNING. AS MUCH AS 1.5 TO 2
INCHES MAY HAVE FALLEN IN ONE AREA OF CAROLINA BUT MOST AREAS ON
THE NORTH COAST OF PUERTO RICO AND AREAS DIRECTLY EAST RECEIVED A
MEASURABLE AMOUNT OF LESS THAN ONE INCH. WATER VAPOR IMAGERY
SHOWS THE UPPER LEVEL TROUGH FORMING OVER THE EASTERN DOMINICAN
REPUBLIC AND IT IS EXPECTED THAT THE UPPER LEVEL CUT-OFF LOW WILL
SOON APPEAR. THE FRONTAL BOUNDARY IS SLOWING ITS SOUTHWARD SINK
AND IT IS LIKELY THAT IT WILL STILL BE ENCOUNTERED OVER CENTRAL
PUERTO RICO BY 18Z. THIS SHOULD BE IDEAL FOR THE DEVELOPMENT OF
SHOWERS AND SCATTERED THUNDERSTORMS IN THAT AREA AND IT IS LIKELY
THAT SOME AREAS OF WESTERN AND INTERIOR PUERTO RICO WILL HAVE
SOME URBAN AND SMALL STREAM FLOODING...AND PERHAPS SOME RIVER
RISES IF ENOUGH HEATING DEVELOPS. HAVE HELD OFF ON ISSUING A
FLASH FLOOD WATCH FOR THE AREA DUE TO LACK OF UPPER LEVEL
DYNAMICS AFTER 02/12Z AND UNCERTAINTY OF MID LEVEL MOISTURE. IT
MAY STILL BE NECESSARY SHOULD THE 12Z SOUNDING SHOW FAVORABLE
CONDITIONS. THE BOUNDARY MOVES SOUTH AND FADES TONIGHT. THE GFS
AND NAM BRING MOISTURE BANDS FROM THE EAST OVER THE AREA ON
MONDAY...WHILE THE ECMWF HOLD A GENERALLY MOIST ATMOSPHERE OVER
THE AREA UNTIL DRYER AIR FORCES IT OUT AND AWAY TO THE SOUTHWEST
TUESDAY NIGHT AND WEDNESDAY. THE ECMWF ALSO BRINGS THE SAME
BOUNDARY BACK ON FRIDAY WHILE THE GFS BRINGS IN WAVES OF MOISTURE
THAT CONTINUE FROM FRIDAY TO THE FOLLOWING TUESDAY...LIKELY RIGHT
ON THROUGH MID- MONTH. MEANWHILE FAVORABLE MJO CONDITIONS SHOW NO
SIGN OF LEAVING THE AREA SOON. IN ANY CASE EXPECT WET CONDITIONS
ACROSS THE AREA UNTIL TUESDAY NIGHT OR WEDNESDAY AS THE SECOND
CLIMATOLOGICALLY WETTEST MONTH IN SAN JUAN AND MUCH OF THE AREA
MAKES ITS ENTRANCE.
&&
.AVIATION...
SHRA OR VCSH CONDITIONS WILL PREVAIL ACROSS TJSJ...TJBQ...TIST
THROUGH 02/18Z WITH TEMPORARY PERIODS OF MVFR. TJMZ WILL REMAIN
VFR THROUGH 02/16Z...SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP AROUND 02/17-02/21. TJPS AND TISX VFR THROUGH 02/17Z WITH
VCNTY SHWRS REST OF PERIOD. LLVL WIND FLOW ENE AT 15 TO 20 KTS
WITH GUSTS.
&&
.MARINE...SEAS ARE EXPECTED TO INCREASE SOMEWHAT WITH WINDS BUT
SHOULD IN GENERAL REMAIN JUST BELOW SMALL CRAFT ADVISORY
CONDITIONS. SEAS IN THE ATLANTIC DIMINISH TUESDAY THROUGH
SATURDAY...BUT INCREASE A LITTLE IN THE CARIBBEAN LATE IN THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 88 76 / 60 40 50 70
STT 86 78 87 78 / 60 40 50 60
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
07/12
!? These... don't want to give up? Thanks to keep us informed as usual Luis, we appreciate us in the islands 
Good news Gusty that for now no new flood advisories have been up as the weather has calmed a bit.Lets see if by this afternoon and tonight,showers return or not.
