Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 191550
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1150 AM AST SAT APR 19 2014

.UPDATE...LOW TO MID LEVEL MOISTURE CONTINUED TO SURGE ACROSS THE
REGION CARRIED BY STRONG EASTERLY TRADE WINDS. PERIODS OF ISOLATED
TO SCATTERED SHOWERS WITH BRIEF WINDS GUSTS UP TO AS MUCH AS 30
MPH ACCOMPANIED THESE PASSING SHOWER WHICH AFFECTED BOTH THE VIRGIN
ISLANDS AND PUERTO RICO...AS WELL AS PARTS OF CULEBRA AND VIEQUES.
EXPECT MOST OF THE SHOWER ACTIVITY AND CLOUDINESS TO DIMINISH BY
12:00 PM AST LEAVING A MIXTURE OF SUNSHINE AND CLOUDS DURING THE
REST OF THE AFTERNOON HOURS IN MOST AREAS. HOWEVER...THE EFFECTS
OF STRONG LOW LEVEL CONVERGENCE...COMBINED WITH DIURNAL AND LOCAL
TERRAIN INFLUENCES WILL CAUSE SHOWERS TO REDEVELOP MAINLY ACROSS
PARTS OF THE INTERIOR AND WEST SECTIONS OF PUERTO RICO...AS WELL
AS IN ISOLATED AREAS IN THE VIRGIN ISLANDS. AT THIS TIME DO NO
EXPECTED SIGNIFICANT RAINFALL ACCUMULATIONS OR FLOOD PROBLEMS AS
THE ACTIVITY SHOULD DEVELOP AND MOVE QUICKLY IN AND OUT OF THE
AREA IN THE FORM OF STREAMERS. NO CHANGES MADE TO THE INHERITED
SHORT TERM FORECAST AT THIS TIME.

&&

.AVIATION UPDATE...SCT-BKN CLD LYRS BTW FL020-FL100 WITH EMBEDDED
-SHRA/SHRA AND FEW TCU QUICKLY MOV WNW ACROSS THE RGN EN ROUTE
BTW PR AND NRN LEEWARDS. BRIEF PRD OF MVFR CONDS WILL REMAIN PSBL
IN AND VCTY TJSJ...TIST...TISX...TNCM AND TKPK TIL AT LEAST 19/16Z.
MTN OBSCR WILL REMAIN PSBL OVR ERN INTERIOR OF PR DURG THE AM...
THEN OVR PARTS OF THE CENTRAL AND WEST INTERIOR OF PR DURG THE AFTN.
ISOLD-SCT SHRA DVLPMNT FM 19/17Z-19/22Z OVR NW AND WRN PR WITH CHC
OF ISOLD TSRA IN AND AROUND TJBQ...TJMZ. LLVL WINDS FM E AT1 5-25
KTS FCST BLW FL100....AS WELL AS BRIEF SFC WND GUSTS OF UP TO 27
KTS OR SO MAINLY WITH PASSING SHRA/ISOLD TSRA.

&&

.MARINE...FRESH TO STRONG EASTERLY TRADE WINDS AND OCCASIONAL WND
GUSTS OBSERVED ACROSS THE LOCAL WATERS...ALONG WITH PERIODS OF
MODERATE TO LOCALLY HEAVY PASSING SHOWERS. DUE TO THE CHOPPY AND
HAZARDOUS SEAS...SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR MOST
OF THE LOCAL WATERS AND PASSAGES EXCEPT FOR THE NEAR SHORE COASTAL
WATERS OF PUERTO RICO WHERE SMALL CRAFT OPERATORS SHOULD STILL EXERCISE
CAUTION. EXPECT THE EASTERLY TRADE WINDS TO GRADUALLY DIMINISH OVERNIGHT
THROUGH SUNDAY...WITH OVERALL IMPROVEMENT IN THE SEA CONDITIONS BY MONDAY.

&&

.PREV DISCUSSION... /ISSUED 518 AM AST SAT APR 19 2014/

SYNOPSIS...UPPER LEVEL RIDGE WILL HOLD THROUGH THE END OF THE WEEK.
RIDGE WILL FLATTEN EARLY NEXT WEEK AS UPPER LEVEL PERTURBATIONS
STREAM NORTH OF THE AREA. A WETTER PATTERN IS FORECAST FOR LATE
NEXT WEEK.

DISCUSSION...AN INCREASE IN MOISTURE HAS BEEN OBSERVED ACROSS THE
LOCAL AREA OVERNIGHT AND EARLY THIS MORNING. SCATTERED SHOWERS
WERE AFFECTING THE NORTH AN EAST SECTIONS OF PUERTO RICO AND THE
U.S. VIRGIN ISLANDS. UNDER THE PREVAILING EASTERLY WIND
FLOW...EXPECT THE CONTINUED TREND OF PASSING SHOWERS ACROSS THE
NORTH AND EAST COASTAL SECTIONS OF THE ISLANDS DURING THE
EARLY MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL
BE MAINLY FOCUSED ACROSS WESTERN PUERTO RICO. THIS PATTERN IS
EXPECTED TO PREVAIL THROUGH THE WEEKEND...BUT TODAY IS GOING TO BE
THE WETTEST DAY.

FOR MID NEXT WEEK...MODELS ARE SHOWING A WETTEST SCENARIO...AS A
SERIES OF UPPER LEVEL PERTURBATIONS MOVES ACROSS THE LOCAL AREA.
IN ADDITION...SURFACE WINDS ARE EXPECTED TO SHIFT MORE
SOUTHERLY...AS A SURFACE LOW PRESSURE SYSTEM EXIT THE U.S EAST
COAST NEXT WEEK. THIS WILL TRANSPORT DEEP MOISTURE FROM THE
SOUTH...WHICH WILL ENHANCE BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS OVER THE AREA.

AVIATION...PATCHES OF LOW LEVEL MOISTURE WITH EMBEDDED PASSING SHRA
WILL CONTINUE TO AFFECT PORTIONS OF THE FLYING AREA TODAY. AS A
RESULT...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE NEAR
TJSJ...TIST... TISX...TNCM AND TKPK UNTIL AT LEAST 19/14Z. MOUNTAIN
OBSCURATION WILL BE POSSIBLE ACROSS THE INTERIOR AND WESTERN
PORTIONS OF PUERTO RICO AFTER 19/16Z. LLVL EASTERLY WINDS OF 10-25
KT WILL PREVAIL BELOW 10K FEET.

MARINE...HAZARDOUS SEAS CONTINUED ACROSS THE REGIONAL
WATERS DUE TO FRESH TO STRONG EASTERLY TRADE WINDS AND OCCASIONAL
WINDS GUSTS OBSERVED ACROSS THE LOCAL WATERS ACCOMPANYING PASSING
TRADE WIND SHOWERS. SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR
ALL OF THE LOCAL WATERS AND PASSAGES EXCEPT FOR THE NEAR SHORE
COASTAL WATERS OF PUERTO RICO WHERE SMALL CRAFT OPERATORS SHOULD
STILL EXERCISE CAUTION DUE TO MODERATE TO LOCALLY FRESH TRADE
WINDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  75  87  75 /  40  40  40  40
STT  85  75  86  77 /  50  50  50  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL NOON AST SUNDAY FOR ANEGADA PASSAGE
     SOUTHWARD TO 17N-ATLC WATERS OF PUERTO RICO AND USVI FROM
     10NM TO 19.5N-CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO
     17N-COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM-
     COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM-
     COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM-
     COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO
     RICO OUT 10 NM-MONA PASSAGE SOUTHWARD TO 17N.

&&

$$

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