High Surf Advisory 8, NWS JSJ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
930 AM AST WED MAR 25 2009

.UPDATE...INCREASED POPS AND WEATHER ACROSS THE NORTH COAST AND
ATLC WATERS TODAY AS SHEAR LINE/FRONTAL BOUNDARY TO THE NORTH IS
STRONGER THAN MODELS HAVE FORECAST. IN FACT...MAY EVEN BE A
THUNDERSTORM OR TWO OVER THE NERN CORNER OF LOCAL ATLC WATERS.
THESE SHOWERS WILL MOVE SOUTH DURING THE DAY...PRIMARILY
INCREASING CLOUD COVER AND SHOWER ACTIVITY OVER NORTHERN PUERTO
RICO...AND PERHAPS A SHOWER OR TWO OVER SWRN PR LATE THIS AFTERNOON.

BUOY 41403 ALSO SHOWING 20 KNOTS OF WIND NORTH OF THE LOCAL
AREA...THESE WINDS WILL OVERSPREAD THE NORTHERN ISLANDS AND
NORTHERN WATERS TODAY AND TONIGHT.

&&

.AVIATION...BRIEF MVFR CONDITIONS IN SHOWER ACTIVITY LIKELY 14Z
THROUGH 18Z OVER TIST...TJSJ AND MAYBE EVEN TJBQ. BY LATE
AFTERNOON MAY SEE SAME CONDITIONS WITH A SHOWER NEAR TJPS...BY
ABOUT 20Z.

&&

.PREV DISCUSSION... /ISSUED 525 AM AST WED MAR 25 2009/

DISCUSSION...
THE MODERATE TRADE WIND FLOW ACROSS THE NORTHEAST CARIBBEAN WILL BRING
SMALL PATCHES OF SHALLOW LOW LEVEL CLOUDS ACROSS THE LOCAL ISLANDS
AND SURROUNDING WATERS TODAY...AND THROUGH MUCH OF THE WORK WEEK...AS
FAIRLY STRONG SURFACE HIGH PRESSURE ACROSS THE WEST ATLANTIC WILL DOMINATE
THE LOCAL WEATHER PATTERN. WEAKENING UPPER LEVEL TROUGH OVER THE CENTRAL
CARIBBEAN...AND AN UPPER LEVEL RIDGE ACROSS THE EASTERN CARIBBEAN WILL
MAINTAIN A SOUTHWEST WIND FLOW ACROSS THE LOCAL REGION TODAY...WHICH
WILL TRANSPORT PATCHES OF MID TO HIGH LEVEL MOISTURE ACROSS THE REGION
FROM TIME TO TIME. EXPECT LITTLE CHANGE OVER THE NEXT DAY OR SO WITH
MOSTLY FAIR WEATHER SKIES AND ISOLATED SHOWERS ACROSS THE LOCAL ISLANDS...
AS A RELATIVELY DRY AIRMASS WILL DOMINATE THE LOCAL WEATHER CONDITIONS.

LATEST GFS MODEL GUIDANCE WHICH HAS SO FAR INITIALIZED FAIRLY WELL
SUGGESTS THAT LATER THIS EVENING AND INTO THURSDAY MORNING...THE
PREVAILING NORTHEAST TRADES WILL BRING AN AREA OF LOW TO MID LEVEL
MOISTURE FROM AN OLD FRONTAL/SHEAR LINE NORTH OF THE LOCAL AREA
ACROSS THE REGION. THIS IN TURN MAY INCREASE THE CHANCES FOR SOME
SHOWER ACTIVITY MAINLY ALONG THE NORTH COASTAL AREAS OF PUERTO RICO
AND NORTHERN U.S. VIRGIN ISLANDS DURING THE EVENING AND EARLY
MORNING HOURS. OVERALL...EXPECT MOSTLY FAIR WEATHER SKIES TO
PREVAIL DURING THE DAYTIME FOR MUCH OF THE WORK WEEK...WITH A
SLIGHT CHANCE OF MAINLY ISOLATED SHOWERS ACROSS PARTS OF THE
INTERIOR SECTIONS OF PUERTO RICO DURING THE AFTERNOON HOURS...AS
SURFACE HIGH PRESSURE ESTABLISHES ITSELF ACROSS THE WEST ATLANTIC
AND NORTH OF THE LOCAL AREA...AND DRY AND SUBSIDENT MID TO UPPER
LEVEL ATMOSPHERIC CONDITIONS PREVAIL.

THE MAIN FOCUS FOR THE NEXT SEVERAL DAYS WILL CONTINUE TO BE THE
INCREASINGLY ROUGH AND HAZARDOUS SEA CONDITIONS EXPECTED ACROSS THE
LOCAL ATLANTIC WATERS AND CARIBBEAN PASSAGES DURING THE LATTER PART
OF THE WEEK...AS LARGE LONG PERIOD SWELL GENERATED FROM A DEVELOPING
GALE CENTER MOVING ACROSS THE WEST ATLANTIC...INVADES THE REGIONAL
WATERS. THIS WILL GREATLY INCREASE THE LIKELIHOOD OF A HIGH SURF
ADVISORY FOR THE NORTH FACING COASTLINES OF THE LOCAL ISLANDS AS
WELL AS THE POSSIBILITY OF MINOR COASTAL EROSION ESPECIALLY DURING
HIGH TIDE. LOCAL RESIDENTS/BOATERS AND VISITORS SHOULD CLOSELY
MONITOR THE LOCAL MARINE FORECAST CONDITIONS FOR THE REMAINDER OF
THE WEEK AND INTO THE WEEK DUE TO THE DETERIORATING SEAS.

AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT
ALL LOCAL TAF SITES TODAY AND TONIGHT. HOWEVER... BRIEF MVFR
CONDITIONS AND LOCAL MOUNTAIN OBSCURATIONS ARE POSSIBLE IN PASSING
SHRA. IN ADDITION...SURFACE WINDS GUSTS TO NEAR 25 KNOTS ARE
POSSIBLE.

MARINE...
A DEVELOPING LOW PRESSURE SYSTEM ACROSS THE NORTHWESTERN ATLANTIC
WILL BRING INCREASING LONG PERIOD NORTHERLY SWELL ACROSS THE LOCAL
ATLANTIC WATERS AND CARIBBEAN PASSAGES BY THIS AFTERNOON. THESE
SWELLS WILL CREATE HAZARDOUS SURF CONDITIONS BY THURSDAY...PEAKING
FRIDAY AFTERNOON. DUE TO INCREASING SEAS THROUGH FRIDAY...SMALL
CRAFT ADVISORY CONDITIONS WILL CONTINUE FOR THE LOCAL ATLANTIC
WATERS AND CARIBBEAN PASSAGES THROUGH AT LEAST FRIDAY AND POSSIBLY
CONTINUE INTO THE UPCOMING WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  83  71  83  72 /  50  50  20  20
STT  82  71  82  71 /  40  50  20  20

&&

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

93/64/

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
601 AM AST WED MAR 25 2009

AMZ710>745-PRZ001>013-261000-
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-
601 AM AST WED MAR 25 2009

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

.DAY ONE...TODAY AND TONIGHT

LINGERING NORTH SWELLS WILL COMBINE WITH MODERATE TO FRESH TRADE
WINDS THROUGH AT LEAST TONIGHT...TO MAKE FOR DANGEROUS MARINE
CONDITIONS...WITH LOCALLY HAZARDOUS SURF AND RIP CURRENTS LIKELY.
SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR MOST OF THE LOCAL
ATLANTIC AND CARIBBEAN WATERS FOR TODAY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ROUGH AND HAZARDOUS SEA CONDITIONS ARE EXPECTED TO CONTINUE FOR
THE NEXT SEVERAL DAYS ACROSS MOST OF THE LOCAL COASTAL WATERS...AS
NEW...LARGE...LONG PERIOD NORTHERLY SWELLS BEGIN TO BUILD ACROSS
THE LOCAL ATLANTIC WATERS AND THE CARIBBEAN PASSAGES THURSDAY AND
THURSDAY NIGHT...PEAK ON FRIDAY AND THEN CONTINUE THROUGH AT LEAST
SATURDAY. DANGEROUS SURF CONDITIONS AND RIP CURRENTS WILL
DEVELOP...WITH HIGH SURF ADVISORIES LIKELY.

.SPOTTER INFORMATION STATEMENT...

ANY REPORTS OF DANGEROUS SURF WOULD BE GREATLY APPRECIATED.

AMZ715-725-VIZ001-002-261000-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
601 AM AST WED MAR 25 2009

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

.DAY ONE...TODAY AND TONIGHT

LINGERING NORTH SWELLS WILL COMBINE WITH MODERATE TO FRESH TRADE
WINDS THROUGH AT LEAST TONIGHT...TO MAKE FOR DANGEROUS MARINE
CONDITIONS...WITH LOCALLY HAZARDOUS SURF AND RIP CURRENTS LIKELY.
SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR MOST OF THE LOCAL
ATLANTIC AND CARIBBEAN WATERS FOR TODAY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ROUGH AND HAZARDOUS SEA CONDITIONS ARE EXPECTED TO CONTINUE FOR
THE NEXT SEVERAL DAYS ACROSS MOST OF THE LOCAL COASTAL WATERS...AS
NEW...LARGE...LONG PERIOD NORTHERLY SWELLS BEGIN TO BUILD ACROSS
THE LOCAL ATLANTIC WATERS AND THE CARIBBEAN PASSAGES THURSDAY AND
THURSDAY NIGHT...PEAK ON FRIDAY AND THEN CONTINUE THROUGH AT LEAST
SATURDAY. DANGEROUS SURF CONDITIONS AND RIP CURRENTS WILL
DEVELOP...WITH HIGH SURF ADVISORIES LIKELY.

.SPOTTER INFORMATION STATEMENT...

ANY REPORTS OF DANGEROUS SURF WOULD BE GREATLY APPRECIATED.