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684
FXCA62 TJSJ 180228
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1028 PM AST THU APR 17 2014

.UPDATE...NO CHANGE TO PREVIOUS PACKAGE...FORECAST ON TRACK.

FRESH TO STRONG TRADE WINDS WILL CONTINUE TO BRING PASSING SHOWERS
ACROSS THE NORTH AND EAST COASTAL SECTIONS OF THE ISLANDS OVERNIGHT
AND FRIDAY MORNING...FOLLOWED BY AFTERNOON CONVECTION ACROSS WEST
PUERTO RICO.

MODEL GUIDANCE CONTINUES TO INDICATE A DRYING TREND LATE FRIDAY
THROUGH SUNDAY...MEANING SHOWER INTENSITY AND AREAL COVERAGE
DECREASING THROUGH TIME. THE CHANCES FOR SHOWERS INCREASE ONCE
AGAIN EARLY NEXT WORK WEEK AS RIDGE ALOFT WEAKENS.

&&

.AVIATION...SCT-BKN LOW LVL CLD WILL CONTINUE WESTWARD ACROSS THE
FLYING AREA BTW THE NRN LEEWARDS AND EASTERN PR WITH EMBEDDED
PASSING -SHRA/SHRA AND FEW TCU. EXPECT BRIEF PASSING SHOWERS TO
AFFECT TJSJ...TIST...TISX...TNCM AND TKPK TIL AT LEAST 18/12Z.
PERIODS OF MVFR IN SHRA/LOW CIG WITH SFC WND GUST UP TO 26 KTS WILL
REMAIN PSBL MAINLY WITH THE PASSING SHOWERS. BRIEF MTN TOP OBSC WILL
AFFECT PORTIONS OF THE CENTRAL MTN RANGE AFTER 18/16Z. LATEST TJSJ
SOUNDING INDICATED AN EASTERLY WIND FLOW UP TO 25 KNOTS ALL THE WAY
FROM THE SURFACE TO AROUND 15K FEET...BECOMING NORTHWESTWARD AND
STRONGER ALOFT.

&&

.MARINE...FRESH TO STRONG TRADE WINDS EXPECTED THROUGH SATURDAY.
THESE WINDS WILL GENERATE ROUGH SEAS ACROSS MOST OF THE COASTAL
WATERS DURING THE WEEKEND AND MAY GENERATE RIP CURRENTS ESPECIALLY
IN THE NORTH AND EAST FACING BEACHES. WINDS AND SEAS WILL BEGIN
TO SUBSIDE SUNDAY.

&&

.PREV DISCUSSION... /ISSUED 302 PM AST THU APR 17 2014/

SYNOPSIS...UPPER LEVEL RIDGE WILL HOLD THROUGH THE END OF THE WEEK.
RIDGE WILL FLATTEN EARLY NEXT WEEK AS SRN STREAM PERTURBATIONS
STREAM NORTH OF THE AREA. STRONG WINDS AND ROUGH SEAS EXPECTED THU
THROUGH SAT.

DISCUSSION...WINDY AND WET TONIGHT IN WINDWARD AND HIGHER ELEVS.
DRYING INDICATED THROUGH THE DAY FRI AND THIS SEEMS REASONABLE
PER LATEST BLENDED TPW PRODUCT WHICH SHOWS DRYER AIR UPSTREAM
NORTHEAST OF THE LEEWARDS AND UNDER UPPER LEVEL RIDGE AXIS.

MODELS CONTINUE TO INDICATE MID-UPPER LEVEL RIDGE AXIS ERODING BY
MONDAY AS INFLOW OF SRN STREAM ENERGY MOVES INTO THE AREA. THIS
RESULTS IN MOISTURE DEEPENING AS SUBSIDENCE INVERSION ERODES.
HOWEVER...THE MODELS ARE NOT AS AGGRESSIVE AS THEY WERE YESTERDAY
WITH THE DEPTH OF MOISTURE AND NOW INDICATE LESSER RAINFALL ACCUMULATIONS.

AVIATION...SCT-BKN LOW LVL CLD WILL CONT WESTWARD ACROSS THE FLYING
AREA BTW THE NRN LEEWARDS AND PR WITH EMBEDDED PASSING -SHRA/SHRA
AND FEW TCU. EXPECT BRIEF PASSING SHOWERS TO AFFECT MOST TAF SITES
TIL AT LEAST 18/22Z. PRD OF MVFR IN SHRA/LOW CIG WITH SFC WND GUST
UP TO 26 KTS WILL REMAIN PSBL MAINLY WITH THE PASSING SHOWERS. BRIEF
MTN TOP OBSC WILL AFFECT PORTIONS OF THE CENTRAL MTN RANGE TIL
17/22Z. LOW LEVEL WNDS MAINLY FM E AT 15-20 KTS BLO FL150...BCMG FM
N-NW AND INCR W/HT ABV TO MAX WND OF AROUND 60 KTS NR FL400. FM
18/03Z-18/12Z ANOTHER SURGE OF SCT-BKN L/LVL CLDS W/EMBEDDED
ISOLD-SCT SHRA IS FCST TO AFFECT PARTS OF ERN PR...TJSJ...TISX AND
TIST.

MARINE...EAST WINDS UP TO 22 KNOTS AND ROUGH SEAS. GUIDANCE
SUGGESTS SEAS UP TO 9 FT IN ATLC WATERS. BELIEVE SEAS WILL BE MORE LIKE
IN THE 5-7 FT RANGE BUT WILL KEEP 6-8 FT FOR CONTINUITY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  77  85  76  85 /  60  60  40  40
STT  77  85  77  86 /  50  50  40  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...
VI...
COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 6 AM 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 SOUTHERN USVI VIEQUES AND EASTERN PUERTO
     RICO OUT 10 NM-MONA PASSAGE SOUTHWARD TO 17N.

     SMALL CRAFT ADVISORY FROM 6 AM TO 5 PM AST FRIDAY FOR COASTAL
     WATERS OF SOUTHERN PUERTO RICO OUT 10 NM.

     SMALL CRAFT ADVISORY FROM 3 PM FRIDAY TO 6 AM AST SUNDAY FOR
     COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM.

&&

$$

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