FXCA62 TJSJ 200927
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
527 AM AST SAT SEP 20 2008
.DISCUSSION...DURING THE OVERNIGHT HOURS THE DOPPLER WEATHER RADAR 
DETECTED SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MAINLY ACROSS 
THE COASTAL WATERS. SOME OF THESE SHOWERS AND THUNDERSTORMS AFFECTED 
OCCASIONALLY THE EASTERN AND NORTHERN SECTIONS OF PUERTO RICO AS 
WELL VIEQUES AND CULEBRA...BUT DUE TO THE RAPID MOVEMENT OF THE 
SHOWERS THE TOTAL RAINFALL ACCUMULATIONS WERE GENERALLY LESS THAN A 
HALF OF AN INCH
THE MAIN CONCERN TODAY FOR OUR FA IS THE LARGE AREA OF DISTURBED 
WEATHER ASSOCIATED WITH A TROPICAL WAVE AND A BROAD AREA OF LOW 
PRESSURE ACROSS THE EASTERN CARIBBEAN THIS MORNING. THIS SYSTEM IS 
PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS OVER THE LESSER 
ANTILLES...AND ADJACENT CARIBBEAN AND ATLANTIC WATERS. THIS SYSTEM
WAS NEAR STATIONARY DURING THE PAST 12 HOURS BUT WILL MOVE VERY
SLOWLY WEST NORTHWEST TODAY AND TOMORROW...PASSING ACROSS OR VERY
CLOSE TO THE LOCAL ISLANDS DURING THE REST OF THE WEEKEND. LATEST
PROJECTIONS OF THE GFS MODEL GUIDANCE INDICATED THAT THE BULK OF
DEEP TROPICAL MOISTURE WILL MOVE ACROSS OR VERY CLOSE TO THE FA
LATER TONIGHT OR ON SUNDAY AS A STRONG OPEN WAVE. ACCORDINGLY TO
THE GFS AND NAM GUIDANCES A MOIST AND UNSTABLE ENVIRONMENT WILL
PREVAIL ACROSS THE REGION DURING THE NEXT SEVERAL DAYS. LATEST
TWOAT FROM NHC INDICATED THAT THE UPPER LEVEL WINDS ARE EXPECTED
TO BECOME MORE CONDUCIVE FOR SOME DEVELOPMENT OF THIS SYSTEM OVER
THE NEXT COUPLE OF DAYS.
IN THE MEANTIME...THE COMBINATION OF THE ABUNDANT TROPICAL
MOISTURE AHEAD OF THIS SYSTEM WITH FAVORABLE UPPER LEVEL
CONDITIONS WILL PROMOTE THE DEVELOPMENT OF NUMEROUS SHOWERS AND
SCATTERED THUNDERSTORMS WITH GUSTY WINDS ACROSS THE LOCAL ISLANDS
AND COASTAL WATERS THIS AFTERNOON...WITH THE POTENTIAL TO PRODUCE
HEAVY RAINFALL ACROSS THE LOCAL ISLANDS WHICH COULD RESULT IN
FLASH FLOODING IN LOW LYING AND POOR DRAINAGE AREAS. ALL RESIDENTS
AND VISITORS ACROSS PUERTO RICO AND THE U.S. VIRGIN ISLANDS SHOULD
CONTINUE TO CLOSELY MONITOR THIS SYSTEM DURING THE REST OF THE
WEEKEND.
ANOTHER TROPICAL WAVE IS FORECAST TO REACH THE FA BY WEDNESDAY...AND 
THEREFORE...THE WET WEATHER PATTERN ACROSS THE REGION WILL CONTINUE 
UNTIL THE LAST PART OF THE UPCOMING WORK WEEK.   
&&
.AVIATION...PASSING CLOUDS AND SHOWERS WILL CONTINUE TO MOVE ACROSS 
THE LOCAL FLYING AREA THROUGH 14Z THIS MORNING. SOME OF THESE CLOUDS 
AND SHOWERS WILL BRING BRIEF PERIODS OF MVFR CONDITIONS TO TNCM... 
TKPK...AND TJSJ. ACTIVITY WILL INCREASE DURING THE REST OF THE DAY 
AS TROPICAL MOISTURE ASSOCIATED WITH A BROAD AREA OF  DISTURBED 
WEATHER AND AN ASSOCIATED TROPICAL WAVE ENTER THE REGION AND MOVES 
WEST NORTHWEST ACROSS THE LOCAL FLYING AREA. AFTERNOON SHOWERS AND 
THUNDERSTORM DEVELOPMENT WILL LEAD TO PERIODS OF IFR AND MVFR ACROSS 
PARTS OF THE CORDILLERA CENTRAL OF PUERTO RICO...AND MAINLY IN AND 
AROUND TJSJ...TJPS...AND PARTS OF THE U.S.VIRGIN ISLANDS. HOWEVER 
SHOWER ACTIVITY WILL BE BRIEF. WINDS THE PREVAILING EASTERLY WINDS 
ARE EXPECTED TO INCREASE SATURDAY AFTERNOON AND BECOME MORE GUSTY
IN NATURE. NO OTHER SIGNIFICANT OPERATIONAL IMPACTS EXPECTED AT THIS 
TIME. 
&&
.MARINE...GENERALLY EXPECT WINDS OF 19 KNOTS OR LESS AND SEAS OF 6 
FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH TONIGHT. WINDS AND 
SEAS WILL BE HIGHER NEAR THUNDERSTORMS AND SQUALLS THIS AFTERNOON 
AND TONIGHT. WINDS AND SEAS WILL INCREASE ACROSS THE REGIONAL WATERS 
IF THE DISTURBANCE OVER THE SOUTHEAST CARIBBEAN BECOMES STRONGER 
THAN CURRENTLY EXPECTED. THERE IS A PRECAUTIONARY STATEMENT FOR THE 
OFFSHORE ATLANTIC WATERS AND FOR THE LOCAL EASTERN CARIBBEAN WATERS 
TODAY.       
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU  87  77  88  77 /  50  50  50  50 
STT  86  78  86  78 /  50  50  50  50 
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
09/72/