Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 261602
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1202 PM AST WED NOV 26 2014

.UPDATE...
NO CHANGES WERE MADE. A DRY SLOT STILL OBSERVED BY SATELLITES
IMAGES OVER PUERTO RICO AND THE US VIRGIN ISLANDS. THE SOUNDING
TOTAL PRECIPITABLE WATER (TPW) REPORTED 1.68 INCHES...SUGGESTING
VALUES AROUND THE CLIMATOLOGICAL MEAN VALUES FOR THE MONTH OF
NOVEMBER. THEREFORE...CONTINUE TO EXPECT LIGHT TO MODERATE TRADE
WIND PASSING SHOWERS MAINLY OVER THE EASTERN SECTIONS OF PUERTO
RICO AND THE US VIRGIN ISLANDS. THE MODEL GUIDANCE CONTINUE TO
SUGGEST SATURDAY WITH THE BEST CHANCE OF SHOWER ACTIVITY.

&&

AVIATION...VFR CONDITIONS EXPECTED NEXT 24 HOURS AT ALL TERMINALS.
EASTERLY WINDS WILL CONTINUE AT 10-25 KT WITH HIGHER GUSTS.

&&

MARINE...SMALL CRAFT ADVISORY CONTINUE IN EFFECT FOR MOST OF THE
LOCAL WATERS DUE TO WINDS UP TO 21 KTS AND SEAS UP TO 7 FEET.
WINDS DIMINISHING TONIGHT THROUGH FRI AS SURFACE GRADIENT WEAKENS
WITH SEAS SUBSIDING TO 3-5 FT.

&&

.PREV DISCUSSION... /ISSUED 340 AM AST WED NOV 26 2014/

SYNOPSIS...UPPER LEVEL LOW OVR THE CNTRL ATLC WILL RETROGRESS
TOWARD 60W BY THANKSGIVING DAY. UPPER LEVEL RIDGE WILL BUILD ON
FRI THEN FLATTEN DURING THE WEEKEND AS SRN STREAM TROF MOVES
ACROSS THE SW ATLC.

DISCUSSION...UPPER LEVEL CONVERGENCE ON BACKSIDE OF RETROGRESSING
UPPER LOW WILL MAINTAIN STRONG SUBSIDENCE INVERSION THROUGH 12Z
SAT GREATLY INHIBITING SHOWER DEVELOPMENT. A SRN STREAM TROF WILL
MOVE ACROSS THE ATLC NORTH OF 20N DURING THE WEEEKEND AND ERODE
THE RIDGE AND ASSOCIATED SUBSIDENCE INVERSION PROMOTING MOISTURE
TRANSPORT AND STEEPENING LAPSE RATES WITH SCT SHOWERS DEVELOPING
IN THE AFTERNOON OVR INLAND AREAS. WINDS ALSO STRENGTHEN SAT INTO MID
NEXT WEEK ENHANCING NOCTURNAL SHOWER ACTIVITY ON WINDWARD AREAS.
THE STEERING FLOW BECOMES MORE FROM THE NORTHEAST SUN INTO WED
FAVORING MAINLY THE SOUTH COAST FOR PRECIP DURING THE DAY AND
NORTHEAST PR AT NIGHT.

AVIATION...VFR CONDITIONS EXPECTED NEXT 24 HOURS AT ALL TERMINALS.
EASTERLY WINDS WILL CONTINUE AT 15-25 KT WITH HIGHER GUSTS. NO SIG
OPERATIONAL WX IMPACT AT THIS TIME.

MARINE...NOT AS WINDY TODAY AS COMPARED TO YESTERDAY WITH WINDS UP TO
20 KT. WINDS DIMINISH RAPIDLY TONIGHT THROUGH FRI AS HIGH PRES
SHIFTS EAST AHEAD OF A COLD FRONT WITH SEAS SUBSIDING TO 3-5 FT.
WINDS STRENGTHEN AGAIN SAT INTO MID NEXT WEEK WITH SPEEDS UP TO 20
KT AND SEAS BUILDING 5-7 FT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  78  85  75 /  30  30  10  10
STT  87  79  85  78 /  20  20  10  10

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 6 AM AST THURSDAY FOR ANEGADA PASSAGE
     SOUTHWARD TO 17N-CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM
     TO 17N-MONA PASSAGE SOUTHWARD TO 17N.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT AST TONIGHT FOR ATLC WATERS
     OF PUERTO RICO AND USVI FROM 10NM TO 19.5N-COASTAL WATERS
     OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF
     NORTHERN USVI AND CULEBRA OUT 10 NM-COASTAL WATERS OF
     SOUTHERN USVI VIEQUES AND EASTERN PUERTO RICO OUT 10 NM.

&&

$$

27/23




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