714
FXCA62 TJSJ 030250 AAA
AFDSJU

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1050 PM AST WED OCT 2 2013

.UPDATE...SOUNDING CAME IN AT 2.02 INCHES THIS EVENING WHICH IS
SIMILAR TO THE SOUNDING FROM 24 HOURS AGO. SOUNDER DATA WAS NOT
AVAILABLE DUE TO GOVERNMENT SHUT DOWN. MODELS ARE INCONCLUSIVE AS
TO THE TREND IN MOISTURE CONTENT AND EXPECT NO SIGNIFICANT CHANGES
DURING THE NEXT 24 HOURS. WRF DID SEE THE PEAK PRECIPITABLE WATER OVER
2 INCHES TODAY BUT DOES NOT SEE THE PEAK OVER 2 INCHES THURSDAY AS
THE GFS DOES. WIND DIRECTION WILL BE A PRIMARY PLAYER THURSDAY AS
A SHIFT BACK TO EAST SOUTHEAST FLOW MOVES THE PRIMARY FOCUS BACK
TO CENTER OF WESTERN PUERTO RICO AND THEN TO THE NORTHWEST FRIDAY.
SHOWERS AND THUNDERSTORMS WILL CONTINUE IN ABOUT THE SAME COVERAGE
THURSDAY AND THEN INCREASE FRIDAY.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS CONTINUED OVER WATER IN
BOTH THE ATLANTIC AND CARIBBEAN...AND A FEW SHOWERS WERE SEEN
IN THE NORTHEAST QUARTER OF MAINLAND PUERTO RICO. WOULD EXPECT
THIS TREND TO CONTINUE.


&&

.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST
03/17Z. AFTERNOON CONVECTION OVER THE INTERIOR AND WESTERN PR COULD
PRODUCE TEMPO MVFR OR EVEN IFR CONDS AT TJMZ BTWN 03/17-21Z.
VCSH/VCTS ARE LIKELY NEAR TJBQ...TJPS AND POSSIBLY TJSJ WITH THE
AFTERNOON SHRA/TSRA. MOUNTAIN OBSCURATIONS ARE ALSO LIKELY ACROSS
WESTERN INTERIOR PR. THROUGH THE FORECAST PERIOD...LLVL WIND WILL BE
MAINLY FM THE EAST AT 10-15 KT BLO FL150. LIGHT AND VARIABLE WINDS
ARE EXPECTED ABV 20 KFT AFT 03/06Z.


&&

.MARINE...SEAS ARE INCREASING SLIGHTLY AND NOW RANGE 4 TO 5 FEET
IN OFFSHORE WATERS AND 3 TO 4 FEET IN THE NEAR SHORE WATERS. NO
CHANGE TO PREVIOUS DISCUSSION.

&&

.PREV DISCUSSION... /ISSUED 249 PM AST WED OCT 2 2013/

SYNOPSIS...RIDGE ALOFT WILL CONTINUE TO ERODE TONIGHT...AS UPPER
LEVEL TROUGH AMPLIFIES ACROSS THE WESTERN ATLANTIC. UPPER LOW
ASSOCIATED WITH AFOREMENTIONED TROUGH WILL PREVAIL NORTH OF THE
AREA THROUGH FRIDAY. A SECOND UPPER LEVEL LOW WILL THEN DEVELOP
NORTHWEST OF LOCAL ISLANDS EARLY NEXT WEEK AND REMAIN NEARLY
STATIONARY THROUGH MID NEXT WEEK.

DISCUSSION...VARIABLY TO PARTLY CLOUDY SKIES PREVAILED ACROSS
THE LOCAL ISLANDS TODAY. SHOWERS WITH THUNDERSTORMS AND LOCALLY
HEAVY RAINFALL WERE NOTED ACROSS PORTIONS OF THE CORDILLERA
CENTRAL AS WELL AS WEST PUERTO RICO IN THE AFTERNOON. WINDS WERE
EASTERLY AT 10 TO 15 MPH WITH COASTAL TEMPERATURES IN THE LOW
90S.

THE LOCAL ISLANDS WILL BECOME UNDER THE INFLUENCE OF A MID TO UPPER
LEVEL TROUGH WHICH WILL INTERACT WITH PATCHES OF LOW LEVEL MOISTURE
AND LOCAL EFFECTS TO PRODUCE CLOUDINESS AND SHOWERS WITH THUNDERSTORMS
ACROSS PORTIONS OF THE LOCAL ISLANDS. IN FACT...MODEL GUIDANCE
SUGGESTED A SHARP INCREASE IN PRECIPITABLE WATER OVER THE NEXT FEW
DAYS WITH VALUES PEAKING NEAR 2.2 INCHES FRIDAY NIGHT-SATURDAY MORNING.
AS A RESULT THURSDAY THROUGH THE EARLY PART OF THE UPCOMING WEEKEND...
UNDER A MOIST/UNSTABLE AIR MASS AND THE PREVAILING WIND FLOW...
EXPECT THE CONTINUED TREND OF PASSING SHOWERS ACROSS USVI AND
EASTERN PUERTO RICO DURING THE MORNING HOURS...FOLLOWED BY
AFTERNOON CONVECTION WHICH WILL BE FOCUSED BUT NOT LIMITED TO
WESTERN PUERTO RICO. SUNDAY INTO EARLY NEXT WEEK...MOIST AND
UNSTABLE CONDITIONS WILL CONTINUE TO PREVAIL ACROSS THE FORECAST
AREA AS A SECOND UPPER LEVEL LOW DEVELOPS NORTHWEST OF THE LOCAL
AREA AND A BROAD SURFACE TROUGH DOMINATES THE CENTRAL AND WESTERN
CARIBBEAN.

AVIATION...VFR CONDITIONS WITH BRIEF MVFR IN ISOLD/SCT SHRA/TSRA
THIS AFTERNOON UNTIL 02/23Z ACROSS WEST INTERIOR PR TO WESTERN
SHORE...CAUSING OBSCURED MTNS AND MVFR TO ISOLD IFR.  WIND UP TO 2 KFT
NE 5-15 KT THRU TONIGHT THEN ENE THU.

MARINE...SEAS 3 TO 5 FEET EXPECTED THROUGH TOMORROW IN MIXED NNE
SWELLS AND ENE WIND WAVES...DIMINISHING TO 2 TO 3 FEET FRIDAY INTO
THE WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  77  88  81  88 /  40  40  50  50
STT  82  88  82  89 /  50  50  50  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&

$$

11/12