Small Craft Advisory 40, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
312 PM AST FRI AUG 21 2009

.DISCUSSION...
WEAK LOW TO MID LEVEL TROUGH INDUCED BY THE DEPARTING HURRICANE BILL
WILL CONTINUE TO MOVE ACROSS THE REGION DURING THE EVENING HOURS AND
EXIT THE AREA BY SATURDAY MORNING..AS STRONG HIGH PRESSURE ACROSS
THE EAST ATLANTIC BUILDS SOUTHWEST ACROSS THE NORTHEAST CARIBBEAN
AND WE RETURN TO MORE OF A NORMAL EASTERLY WIND FLOW.

EXPECT BRIEF LINES OF SHOWERS TO MOVE ACROSS THE LOCAL AREA DURING
THE EVENING AND OVERNIGHT HOURS ACCOMPANYING A WEAK CONVERGENT
ZONE WHICH HAS SET UP BETWEEN THE DEPARTING ABOVE MENTIONED TROUGH
AND ATLANTIC RIDGE. THE RIDGE WILL CONTINUE TO BUILD INTO THE
AREA AND BRING DRIER AND STABLE CONDITIONS FOR MUCH OF THE
WEEKEND. THE NEXT TROPICAL WAVE NOW LOCATED NEAR 57 WEST IS
EXPECTED TO MOVE ACROSS THE EASTERN CARIBBEAN LATE SATURDAY INTO
SUNDAY...BUT EXPECT MOST OF THE ASSOCIATED MOISTURE TO PASS MAINLY
SOUTH OF ISLANDS. ANOTHER TROPICAL WAVE IS FORECAST TO ENTER THE
EASTERN CARIBBEAN EARLY MONDAY AND MOVE ACROSS THE LOCAL REGION
AFFECTING THE AREA MONDAY INTO TUESDAY. THIS WILL BE ACCOMPANIED
BY TUTT LOW WHICH IS FORECAST TO MOVE ACROSS THE REGION FROM THE
TROPICAL ATLANTIC AND WILL MOVE TO JUST NORTH OF THE LOCAL ISLANDS
ON MONDAY. THE COMBINATION OF THESE TWO FEATURES COULD BRING SOME
ACTIVE WEATHER CONDITIONS TO THE LOCAL ISLANDS AND SURROUNDING
WATERS IF THIS SCENARIO PANS OUT. LATEST GFS MODEL GUIDANCE
INITIALIZED WELL WITH THE PRESENT CONDITIONS...AND SUGGEST DRIER
CONDITIONS ACROSS THE AREAS MUCH OF THE WEEKEND...WITH INCREASING
MOISTURE DURING THE EARLY PART OF THE UPCOMING WEEK...BUT AS USUAL
STILL A FEW DAY OFF SO WILL CONTINUE TO MONITOR. FOR THE NEXT FEW
DAYS EXPECT MAINLY LOCAL EFFECTS AND DIURNALLY INDUCED CONVECTION
ACROSS THE AREA WITH NOCTURNAL SHOWERS AFFECTING THE PARTS OF THE
EAST COASTAL AREAS FROM TIME TO TIME...WITH PREVAILING FAIR WEATHER
SKIES DURING THE DAY.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED ACROSS ALL THE LOCAL TAF SITES OVERNIGHT.
A RETURN TO MORE TYPICAL ENE WIND FLOW OF 15 TO 20 KTS EXPECTED
TOMORROW WITH AFTERNOON SHOWER DEVELOPMENT OVER THE INTERIOR OF
PR...EVENTUALLY SPREADING IN TJMZ AFT 22/18Z.

&&

.CLIMATE...SOUTHERLY WINDS BEHIND HURRICANE BILL BROUGHT VERY WARM
TEMPERATURES ACROSS THE NORTHERN HALF OF PR TODAY. WHILE THE
TEMPERATURE IN SAN JUAN WILL LIKELY FALL SHY OF THE RECORD 97
RECORDED ON THIS DATE IN 1980...TODAY WILL MARK THE SECOND WARMEST
AUGUST 21ST ON RECORD...WITH THE TEMPERATURE LAST HITTING 93 IN 2007.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  79  88  78  87 /  30  30  20  40
STT  81  88  79  89 /  30  20  20  40

&&

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

04/09

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
535 AM AST FRI AUG 21 2009

AMZ710>745-PRZ001>013-220945-
SAN JUAN AND VICINITY-NORTHEAST-SOUTHEAST-EASTERN INTERIOR-
NORTH CENTRAL-CENTRAL INTERIOR-PONCE AND VICINITY-NORTHWEST-
WESTERN INTERIOR-MAYAGUEZ AND VICINITY-SOUTHWEST-CULEBRA-VIEQUES-
THE NEARSHORE AND OFF SHORE ATLANTIC AND CARIBBEAN COASTAL WATERS-
535 AM AST FRI AUG 21 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE
ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT
THE LARGE...LONG PERIOD...EAST NORTHEAST SWELLS GENERATED BY BILL
WILL START TO DECREASE THIS MORNING ACROSS THE ATLANTIC WATERS AND
THE NORTHEAST CARIBBEAN PASSAGES...THERE STILL IS A HIGH POTENTIAL
FOR RIP CURRENTS TO OCCUR ALONG THE NORTHERN AND EASTERN SHORES OF
PUERTO RICO.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

AMZ715-725-VIZ001-002-220945-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
535 AM AST FRI AUG 21 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND
THE ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT
THE LARGE...LONG PERIOD...EAST NORTHEAST SWELLS GENERATED BY BILL
WILL START TO DECREASE THIS MORNING ACROSS THE ATLANTIC WATERS AND
THE NORTHEAST CARIBBEAN PASSAGES...THERE STILL IS A HIGH POTENTIAL
FOR RIP CURRENTS TO OCCUR ALONG THE EXPOSE SHORES OF THE LOCAL
ISLANDS.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.