Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 270240
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1040 PM AST FRI DEC 26 2014

.UPDATE...PASSING SHOWERS WERE NOTED OVER THE ATLANTIC COASTAL
WATERS WITH FEW AFFECTING THE NORTHERN HALF OF PUERTO RICO. LATEST
SATELITE IMAGES SHOWS A SLOT OF DRY AIR OVER THE U.S. VIRGIN
ISLANDS. THIS AREA OF DRY AIR WILL MOVE OVER THE REGION NEXT 24
HOURS...WHICH WILL LIMIT THE SHOWER ACTIVITY ACROSS THE REGION.
MINOR CHANGES WERE INTRODUCED TO SHORT TERM GRIDS TO INCREASE A
LITTLE BIT THE CHANCE FOR LIGHT PASSING SHOWERS.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED ACROSS ALL TAF SITES THRU
LATE SATURDAY NIGHT. COLD FRONT WILL REACH THE FLYING AREA FM THE
NORTH ON SUNDAY...INCREASING CLOUDINESS AND SHRA ACTIVITY WITH
POSSIBLE MVFR/IFR CIGS. THE 27/00Z TJSJ UPPER AIR SOUNDING INDICATED
LIGHT EASTERLIES AT THE SFC BUT INCREASING UP TO 17 KT FROM THE E-NE
BELOW FL020.

&&

.MARINE...BUOY 41044 NEAR 500 MILES NORTHEAST OF SAN JUAN WAS
SHOWING WAVE HEIGHT OF 9 FEET AT 16 SECONDS. THESE SWELLS WILL
ARRIVE TO OUR COASTAL WATER SATURDAY MORNING. REFER TO LATEST
COASTAL HAZARD MESSAGE PRODUCTS FOR MORE INFORMATION.


&&

.PREV DISCUSSION... /ISSUED 252 PM AST FRI DEC 26 2014/

SYNOPSIS...UPPER LEVEL RIDGE WILL SHIFT SOUTHWEST DURING THE NEXT
SEVEN DAYS LOSING ITS GRIP OVER THE LOCAL AREA. A COLD FRONT WILL
MOVE THROUGH THE AREA SUN AFTERNOON.

DISCUSSION...DRY AIR WILL ADVECT INTO THE LOCAL AREA TONIGHT
THROUGH SATURDAY YIELDING NICE WEATHER. SOME AREAS OF FOG ARE
LIKELY TONIGHT DUE TO MID LEVEL SUBSIDENCE...CLEAR SKIES AND WET
GROUND. A CDFNT WILL MOVE THROUGH THE AREA SUN AFTERNOON BRINGING
PLENTY OF CLOUDS WITH SCT-NMRS SHOWERS ESPECIALLY ON THE NORTH
SIDE OF THE CNTRL CORDILLERA. THINGS DRY OUT LATE SUN NIGHT THRU
TUE UNDER BUILDING SFC HIGH PRESSURE. A MID-UPPER LEVEL TROF IS
EXPECTED TO PASS THROUGH THE AREA NEXT WED BRINGING AN INCREASE IN
MOISTURE/SHOWERS. UPPER LEVEL CONVERGENCE THEN STRENGTHENS TOWARD
THE END OF NEXT WEEK WITH A STRONG PRESSURE GRADIENT ESTABLISHING
OVER THE AREA DUE TO BUILDING HIGH PRES NORTH OF THE AREA. EXPECT
VERY WINDY CONDITIONS NEXT FRI JAN 02 - SAT JAN 03. THIS IS LIKELY
TO RESULT IN HEIGHTENED FIRE WX CONDITIONS AROUND CAMP SANTIAGO
WHERE SIG DRYING HAS BEEN OCCURRING SINCE EARLY DEC.

AVIATION...OVERALL VFR CONDS ARE EXPECTED ACROSS MOST OF THE TAF
SITES THRU SAT. THEN...COLD FRONT REACHES THE FLYING AREA FM THE NORTH
ON SUNDAY...WITH INCREASING CLOUDINESS AND SHOWER ACTIVITY AS
WELL AS THE POSSIBILITY OF MVFR/IFR CIGS IN SHRA. ENE WINDS 10-15
KT BECOMING NE SAT AND INCREASING 15-20 KT SUN.

MARINE...LARGE NORTHEAST SWELLS WILL BEGIN IMPACTING THE ATLC
COASTAL WATERS LATE TONIGHT AND PEAK SAT NIGHT BEFORE SUBSIDING
MON AND TUE. WINDS WILL DIMINISH TONIGHT AND THEN STRENGTHEN SUN
AFTERNOON THROUGH MON BEHIND A COLD FRONT. HIGH SURF AND SMALL
CRAFT ADVISORIES ARE NOW IN EFFECT THROUGH MONDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  73  83  73  82 /  10  20  70  70
STT  75  85  75  84 /   0  30  70  70

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...HIGH SURF ADVISORY FROM 10 AM SATURDAY TO 6 PM AST MONDAY FOR
     CULEBRA-NORTH CENTRAL-NORTHEAST-NORTHWEST-SAN JUAN AND
     VICINITY-SOUTHEAST-WESTERN INTERIOR.






VI...HIGH SURF ADVISORY FROM 10 AM SATURDAY TO 6 PM AST MONDAY FOR ST
     CROIX-ST. THOMAS/ST. JOHN/ADJACENT ISLANDS.




COASTAL WATERS...
     SMALL CRAFT ADVISORY FROM 6 AM SATURDAY TO MIDNIGHT AST MONDAY
     NIGHT FOR 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.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT AST MONDAY NIGHT FOR ANEGADA
     PASSAGE SOUTHWARD TO 17N-ATLC WATERS OF PUERTO RICO AND
     USVI FROM 10NM TO 19.5N.

&&

$$

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