Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 090345
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1145 PM AST MON FEB 8 2016

.UPDATE...NO SIGNIFICANT CHANGES MADE TO THE INHERITED FORECAST WEATHER
GRIDS AT THIS TIME BASED ON RECENT MODEL GUIDANCE AND PRESENT WEATHER
CONDITIONS. MID TO UPPER LEVEL RIDGE ALOFT WILL CONTINUE TO DOMINATE
THE OVERALL WEATHER CONDITIONS AND LIMIT CONVECTION ACROSS THE ISLANDS
AND COASTAL WATERS AT LEAST THROUGH THE MIDDLE OF THE WORK WEEK. A
BETTER CHANCE FOR SHOWER ACTIVITY AND INCREASING MOISTURE CONVERGENCE
AND INSTABILITY IS FORECAST DURING THE LATTER PART OF THE WEEK...AS
THE RIDGE ERODES ALOFT...AND THE EASTERLY TRADE WINDS INCREASE ACROSS
THE NORTHEASTERN CARIBBEAN.

MARINEWISE...MADE ADJUSTMENTS TO THE MARINE GRIDS BASED ON RECENT
BUOYDATA FROM THE DISTANT OFFSHORE BUOYS 41046 EAST BAHAMAS AND
41047 NE BAHAMAS...WHICH BOTH SUGGESTS SEAS 12-17 FEET AT 12 TO
15 SECONDS.

&&

.AVIATION UPDATE...VFR CONDITIONS ARE EXPECTED TO PREVAIL DURING
THE NEXT 24 HOURS ACROSS ALL TERMINALS. SHOWERS POSSIBLE IN AND
AROUND JBQ AFT 09/17Z. LATEST TJSJ SOUNDING INDICATED A SOUTHERLY
WIND FLOW AT 4 TO 11 KT BELOW 2KFT. SFC WNDS OVERNIGHT LIGHT AND
VARIABLE DUE TO LAND BREEZE...BECOMING EAST TO SOUTHEAST AT 10 TO
15KT AFTER 09/13Z.

&&

.MARINE UPDATE...A DOMINANT LONG PERIOD NORTHWEST SWELL...GENERATED
FROM AN AREA OF LOW PRESSURE ACROSS THE NORTHWESTERN ATLANTIC...WILL
ARRIVE ACROSS THE LOCAL ATLANTIC WATERS ON TUESDAY. THIS WILL RESULT
IN HAZARDOUS SEAS. SMALL CRAFT ADVISORIES WILL BE IN EFFECT FOR THE
ATLANTIC WATERS AND LOCAL PASSAGES AT LEAST UNTIL WEDNESDAY. PLEASE
REFER TO THE LATEST COASTAL WATERS FORECAST AND MARINE WEATHER MESSAGE
ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN PR.

THE ARRIVAL OF LONG PERIOD NORTHWESTERLY SWELL WILL GENERATE BREAKING
WAVES BETWEEN 8 TO 13 FEET BY TUESDAY AFTERNOON ALONG MOST OF THE
ATLANTIC BEACHES OF PUERTO RICO...CULEBRA AND THE NORTHERN U.S.
VIRGIN ISLANDS. THIS WILL RESULT IN A HIGH RISK OF RIP CURRENTS
BEGINNING ON TUESDAY. PLEASE REFER TO THE LATEST COASTAL HAZARD
MESSAGE ISSUED BY WFO SAN JUAN PR FOR ADDITIONAL INFORMATION.

&&

.PREV DISCUSSION... /ISSUED /

SYNOPSIS...A MID TO UPPER LEVEL RIDGE CONTINUES ALOFT. SURFACE
HIGH PRESSURE ACROSS THE EAST CENTRAL ATLANTIC WILL MAINTAIN
GENTLE TO MODERATE TRADE WINDS ACROSS THE REGION THROUGH AT LEAST
MID WEEK. A FRONTAL BOUNDARY WILL REMAIN WELL NORTH OF THE AREA
FOR MOST OF THE WEEK. PATCHES OF LOW LEVEL MOISTURE WILL AFFECT
THE REGION FROM TIME TO TIME.

DISCUSSION...A MID TO UPPER LEVEL RIDGE CONTINUES TO DOMINATE
THE WEATHER CONDITIONS PRODUCING SUBSIDENCE ALOFT. IN
ADDITION...A SURFACE HIGH PRESSURE ACROSS THE EAST CENTRAL
ATLANTIC AND A SURFACE LOW PRESSURE LOCATED OVER THE WESTERN
ATLANTIC OF THE EASTERN COAST OF U.S. WILL MAINTAIN A SOUTH TO
SOUTHEASTERLY WIND FLOW ACROSS THE REGION. THIS WIND FLOW WILL
PRODUCE ABOVE NORMAL TEMPERATURES OVER THE REGION...ESPECIALLY ALONG
THE NORTHERN COASTLINE OF PUERTO RICO. MOSTLY SUNNY SKIES
PREVAILED THIS MORNING FOLLOWED BY AN INCREASE IN CLOUDINESS
MAINLY OVER THE INTERIOR AND DOWNWIND FROM THE SURROUNDING
ISLANDS. ISOLATED TO SCATTERED SHOWERS WILL REMAIN POSSIBLE THIS
AFTERNOON MAINLY OVER THE INTERIOR AND NORTHWESTERN SECTIONS.

FOR THE NEXT FEW DAYS...MOSTLY SUNNY AND RELATIVELY DRY
CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE REGION...WITH
MINIMAL SHOWER ACTIVITY EXPECTED TO DEVELOP ACROSS THE AREA. AFTER
MID WEEK...AN INCREASE IN MOISTURE IS FORECAST AS A FRONTAL
BOUNDARY APPROACHES THE LOCAL AREA FROM THE NORTH INDUCING A SURFACE
TROUGH WHILE INTERACTING WITH A SURGE OF MOISTURE IN THE EASTERLY
WIND FLOW.

AVIATION...VFR CONDITIONS SHOULD CONTINUE THROUGH 09/18Z ACROSS
ALL TERMINALS. AN ISOLATED SHOWER OR TWO COULD DEVELOP VCTY OF
TJBQ BETWEEN 20Z AND 23Z...HOWEVER NO SIGNIFICANT IMPACT EXPECTED
IN OPERATIONS...THEREFORE WILL NOT BE MENTIONED IN TAF. WINDS BLO
FL150 WILL CONTINUE FM THE SE AT 10-15 KTS.

MARINE...SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION ACROSS THE
ATLANTIC OFFSHORE WATERS DUE TO SEAS UP TO 6 FEET. ELSEWHERE...SEAS
BETWEEN 3 TO 5 FEET AND WINDS AROUND 18 KT. A LONG PERIOD
NORTHWEST SWELL IS FORECAST TO REACH THE ATLANTIC WATERS ON
TUESDAY AFTERNOON...THIS WILL RESULT IN HAZARDOUS SEAS AND LIFE
THREATENING RIP CURRENTS ACROSS THE ATLANTIC COASTLINE OF THE
ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  74  89  75  88 /  10  20  30  30
STT  75  85  75  85 /  30  20  40  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...HIGH RIP CURRENT RISK FROM 5 AM AST TUESDAY THROUGH LATE TUESDAY
     NIGHT FOR NORTH CENTRAL-NORTHEAST-NORTHWEST-SAN JUAN AND
     VICINITY-SOUTHEAST-WESTERN INTERIOR.

     HIGH SURF ADVISORY FROM 2 PM TUESDAY TO 5 AM AST WEDNESDAY FOR
     CULEBRA-MAYAGUEZ AND VICINITY-NORTH CENTRAL-NORTHEAST-
     NORTHWEST-SAN JUAN AND VICINITY-SOUTHEAST-WESTERN INTERIOR.

     SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 2 AM AST WEDNESDAY FOR
     NORTH CENTRAL-NORTHWEST.

     HIGH RIP CURRENT RISK FROM TUESDAY AFTERNOON THROUGH LATE
     TUESDAY NIGHT FOR CULEBRA-MAYAGUEZ AND VICINITY.

VI...HIGH SURF ADVISORY FROM 2 PM TUESDAY TO 5 AM AST WEDNESDAY FOR
     ST. THOMAS/ST. JOHN/ADJACENT ISLANDS.

     HIGH RIP CURRENT RISK FROM TUESDAY AFTERNOON THROUGH LATE
     TUESDAY NIGHT FOR ST. THOMAS/ST. JOHN/ADJACENT ISLANDS.

AM...HIGH SURF ADVISORY FROM 2 PM TUESDAY TO 5 AM AST WEDNESDAY FOR
     COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM-
     COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO
     RICO OUT 10 NM.

     SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 2 AM AST WEDNESDAY FOR
     CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N-COASTAL
     WATERS OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF
     NORTHWESTERN PUERTO RICO OUT 10 NM-MONA PASSAGE SOUTHWARD
     TO 17N.

     HIGH RIP CURRENT RISK FROM TUESDAY AFTERNOON THROUGH LATE
     TUESDAY NIGHT FOR COASTAL WATERS OF NORTHERN USVI AND
     CULEBRA OUT 10 NM-COASTAL WATERS OF SOUTHERN USVI VIEQUES
     AND EASTERN PUERTO RICO OUT 10 NM.

     SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 2 PM AST WEDNESDAY FOR
     ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N.

&&

$$

27/09


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