mrpuertorico's WunderBlog

TRADE WIND SURGE WILL LIKELY TRIGGER ADDITIONAL CONVECTION

Posted by: mrpuertorico, 7:43 PM GMT on July 13, 2006

000
FXCA62 TJSJ 221451 AAA
AFDSJU

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1051 AM AST THU SEP 22 2011

.UPDATE...LOW PRES IS GONE BUT A TRADE WIND SURGE EVIDENT ON VIS
IMAGERY AND ON REGIONAL 12Z RAOBS OVR THE LEEWARDS WILL MOVE
ACROSS THE USVI THIS AFTERNOON AND INTO PR THIS EVENING. THIS
SURGE WILL LIKELY TRIGGER ADDITIONAL CONVECTION THIS AFTERNOON PER
GROWING CU FIELD ON RECENT VIS IMAGERY AND MODEL OUTPUT FROM HI-
RES ARW MODELS. CONVECTION IF ITS GET DEEP ENOUGH COULD BE STRONG
TO SEVERE WITH STRONG WINDS JUST ABOVE SFC. FLOODING IS NOT LIKELY
DUE TO EXPECTED FAST MOTION. AFTER TODAY...SHOULD HAVE A COUPLE OF
REALLY DRY DAYS.

&&

.AVIATION...TSTMS APPEAR LIKELY ALONG THE NORTH COAST...USVI AND
LEEWARD ISLANDS TERMINALS. STRONG WIND GUSTS AUGMENTED DUE TO FAST
STORM MOTION ARE LIKELY WITH A TALL THUNDERSTORM.

&&

.PREV DISCUSSION... /ISSUED 500 AM AST THU SEP 22 2011/

DISCUSSION...MOISTURE ASSOCIATED WITH A SMALL BUT VIGOROUS AREA OF
LOW PRESSURE NOW OVER PUERTO RICO AND QUICKLY MOVING WESTWARD IS
BEING ENHANCED BY A MID LEVEL VORT MAX MOVING ACROSS THE AREA...AS
WELL AS OROGRAPHIC FORCING. THIS IS PRODUCING SQUALL LIKE WEATHER
CONDITIONS ACROSS THE ISLANDS AND THE SURROUNDING WATERS. SCATTERED
TO NUMEROUS SHOWERS WITH AREAS OF STRONG THUNDERSTORMS MOVED ACROSS
MUCH OF THE VIRGIN ISLANDS AND THE EAST AND CENTRAL SECTIONS OF
PUERTO RICO DURING EARLY MORNING HOURS. THIS ACTIVITY PRODUCED AND
WILL CONTINUE TO PRODUCE PERIODS OF TORRENTIAL RAINFALL WITH
FREQUENT LIGHTING AND STRONG GUSTY WINDS IN SOME AREAS DURING THE
REST OF THE MORNING.

DURING THE REMAINDER OF THE DAY...THE PROXIMITY OF THIS PROGRESSIVE
LOW PRESSURE CENTER WHICH SHOULD BE OVER THE MONA PASSAGE BY LATE
MORNING...WILL CONTINUE TO INFLUENCE THE WEATHER CONDITIONS ACROSS
THE ISLANDS. WITH FAIRLY DECENT MOISTURE CONTENT AND PWAT VALUES
STILL FORECAST TO BE JUST BELOW TWO INCHES TODAY... EXPECT LOCAL
AND DIURNAL EFFECTS TO ENHANCE THE AFTERNOON CONVECTION OVER MUCH
OF PUERTO RICO AND THE ADJACENT ISLANDS. LINGERING MOISTURE OVER THE
VIRGIN ISLANDS WILL ALSO LEAD TO AREAS OF MOSTLY ISOLATED SHOWERS
AND THUNDERSTORM ACTIVITY DURING THE AFTERNOON HOURS.

TROPICAL STORM OPHELIA LOCATED OVER THE CENTRAL TROPICAL ATLANTIC
SHOWED SOME INTENSIFICATION THIS MORNING...BUT IS STILL FORECAST
TO SLOWLY WEAKEN AND TRACK WESTWARD TODAY...THEN NORTHWESTWARD ON
FRIDAY AND TRACK WELL NORTHEAST OF PUERTO RICO AND THE VIRGIN ISLANDS
LATE SUNDAY OR MONDAY. PLEASE REFER TO THE LATEST BULLETIN/ADVISORY
ON TROPICAL STORM OPHELIA ISSUED BY THE NATIONAL HURRICANE CENTER IN
MIAMI FOR ADDITIONAL INFORMATION.

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