000
FXCA62 TJSJ 101055
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
645 AM AST FRI JUN 10 2005
.DISCUSSION...
VERY ACTIVE WEATHER STILL LOOKS ON TAP FOR THE LOCAL AREA DURING THE
NEXT FEW DAYS AS A TUTT LOW AND ASSOCIATED MID TO UPPER TROUGHING
CURRENTLY EXTENDING FROM THE LEEWARDS NNW INTO THE W CENTRAL
ATLC...DIGS SOUTHWARD INTO THE LOCAL AREA...AND INTERACTS WITH A
VERY MOIST SE FLOW OF TROPICAL MOISTURE.
NWLY FLOW ALOFT OVERNIGHT HAS ACTED TO SHEAR CONVECTIVE ACTIVITY
TRYING TO SHIFT NW INTO THE LOCAL AREA...BUT UPPER SPEED DIVERGENCE
HAS ALLOWED FOR WIDELY SCATTERED DEEP CELLS TO CONTINUE TO FIRE
ACROSS THE OPEN WATER S THROUGH SE OF ST CROIX. TROPICAL MOISTURE
WILL INCREASE ACROSS THE ENTIRE LOCAL AREA DURING THE NEXT 24 HOURS
AS LLVL TROUGH ACROSS E PORTIONS OF OUR AREA CONTINUES TO MOVE WNW
AT 10 MPH...WITH DEEPER MOISTURE AND BETTER LLVL CONVERGENCE ON ITS
E SIDE SHIFTING ACROSS THE AREA THIS AFTERNOON THROUGH SATURDAY. THE
AFOREMENTIONED TUTT LOW WILL CONCURRENTLY DIG SOUTHWARD TO JUST
NORTH OF PUERTO RICO DURING THE SAME TIME TO CREATE EXPLOSIVELY
UNSTABLE MID TO UPPER CONDITIONS. HEAVY RAINFALL THEREFORE LOOKS
LIKELY ACROSS THE REGION...WITH THE POTENTIAL FOR FLASH FLOODING AND
MUDSLIDES. GFS AGAIN IS ATTEMPTING TO DEVELOP A SURFACE LOW...THIS
TIME JUST TO THE S AND SW OF P.R. TONIGHT MOVING WNW ACROSS THE MONA
PASSAGE...AND FOCUSING ABUNDANT MOISTURE AND COPIOUS RAINFALL ON THE
E SIDE OF THE LOW MOVING EN MASS ACROSS P.R. GIVEN THAT THIS BRIEF
WEAK LOW DEVELOPS WITHIN THE LLVL TROUGH AXIS AND UNDERNEATH GOOD
UPPER DIVERGENCE IT STILL SEEMS PLAUSIBLE...BUT REGARDLESS...ITCZ
MOISTURE WILL TRAIL THE LLVL TROUGH INTO THE E CARIB AND SOME OF
THAT ACTIVITY WILL MAKE IT NEAR OR ACROSS THE LOCAL AREA THROUGH
MONDAY.
ALTHOUGH MODELS ARE FORECASTING THE MOST EXPLOSIVE CONDITIONS TO
OCCUR THIS EVENING THROUGH TONIGHT...INSTABILITY FROM THE TUTT LOW
AND ASSOCIATED TROUGHING...AND A SE FEED OF TROPICAL MOISTURE WILL
BOTH CONTINUE TO INFLUENCE THE AREA THROUGH MONDAY.
MARINE CONDITIONS WILL BE DETERMINED BY THE STRENGTH OF THE SE FLOW
BUILDING IN BEHIND THE LLVL TROUGH THIS AFTERNOON THROUGH
SATURDAY...WITH THE GFS DEVELOPING UP TO 30 KNOTS ACROSS OUR WESTERN
WATERS TONIGHT AND SATURDAY DUE TO THE DEVELOPMENT OF THE SURFACE
LOW. I HAVE CHOSEN TO GO A BIT CAUTIOUS WITH THIS AND KEPT MAXIMUM
WINDS AT 22 KNOTS AND MAX SEAS AT 6 FEET. OUTSIDE OF THIS...MAIN
THREAT TO MARINERS WILL BE INTENSE AND/OR POSSIBLY SEVERE WEATHER
REALIZED IN SCATTERED INTENSE THUNDERSTORMS AND SQUALLS...WHICH ARE
MORE LIKELY ACROSS THE LOCAL CARIBBEAN AND ATLC WATERS OF THE VIRGIN
ISLANDS.
T.S. ARLENE MOVING NNW ACROSS FAR W TIP OF CUBA EARLY THIS MORNING
AND THEN INTO THE SE GULFMEX...THEN EXPECTED TO CONTINUE TOWARDS THE
N GULF COAST BETWEEN MOUTH OF MISSISSIPPI AND EXTREME NW FLORIDA BY
MIDNIGHT SUNDAY. STRONGEST WINDS AND DEEPEST TSTORMS HAVE REMAINED
WELL TO THE NE AND REMOVED FROM CENTER OF ARLENE...BUT OVERNIGHT...
TSTORMS ATTEMPTING TO DEVELOP CLOSER TO CENTRAL CIRCULATION. SQUALLY
WEATHER AND STRONG WINDS TO AFFECT S FLORIDA...THE KEYS AND ADJACENT
WATERS TODAY. ARLENE MAY HAVE A CHANCE FOR INTENSIFICATION IN THE
GULF TONIGHT AND SATURDAY AS UPPER SHEAR RELAXES AND THE CENTER
PASSES OVER A VERY LARGE WARM CORE RING DIRECTLY IN ITS FORECAST
PATH. LARGE LLVL CIRCULATION OF ARLENE INDIRECTLY AFFECTING THE
LOCAL STEERING FLOW AND HELPING TO SET UP SE FLOW OF TROPICAL
MOISTURE INTO THE LOCAL AREA THIS WEEKEND.
Once Arlene moves northward away from the western Caribbean it will open the door for what is located in the eastern Caribbean to move west.But there is a TUTT trough in the area that will keep in check this disturbed area but if the trough relaxes it mayturn conditions more favorable and in fact some models show a low near the Bahamas in the next few days.But regardless about development or not plenty of rain for the northern Antilles is a sure bet.So let's watch this mess and see what evolves from it to see if anything forms.
