Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 060241
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1041 PM AST FRI FEB 5 2016

.UPDATE...WEAK LOW PRESSURE OVER THE AREA HAVE MAINTAINED SCATTERED
SHOWERS ACROSS PORTIONS OF THE LOCAL ISLANDS SINCE THIS AFTERNOON.
ALTHOUGH...MOST OF THE SHOWERS HAVE DISSIPATED OVER LAND AT THIS
TIME...LIGHT SHOWERS ARE STILL POSSIBLE ACROSS THE SOUTH COAST OF
PR THE REST OF TONIGHT AND OVERNIGHT. SOME CHANGES WERE INTRODUCED
TO THE FORECAST PACKAGE TONIGHT...MAINLY TO REDUCE THE POPS OVER
LAND THE REST OF TONIGHT AND SATURDAY MORNING.

&&

.AVIATION...VFR IS EXPECTED DURING THE FCST PERIOD. LIGHT AND
VARIABLE WINDS THRU 06/12Z AS LOW PRESSURE MOVES TO NW OF FA.
FLOW FROM SSE WILL START ARND 06/14Z WITH SEA BREEZE VARIATIONS
INCREASING AT 10 TO 15 KT. MINOR SHRA ACTIVITY WITH SOME MOUNTAIN
OBSC OVER THE INTERIOR AND WESTERN PR AFT 06/18Z.

&&

.MARINE...SEAS WILL CONTINUE TO SUBSIDE ACROSS THE LOCAL ATLANTIC
WATERS DURING OVERNIGHT HOURS. THEN...SEAS WILL REMAIN BELOW 6
FEET THROUGH AT LEAST MONDAY. A PULSE OF NNW WILL REACH THE LOCAL
ATLANTIC WATERS ON TUESDAY...INCREASING THE SEAS ONCE AGAIN TO
5-7 FEET.

&&

.PREV DISCUSSION... /ISSUED /

SYNOPSIS...TUTT TO THE EAST-NORTHEAST OF THE AREA WILL CONTINUE
TO WEAKEN AND MOVE EAST...AS UPPER RIDGE BUILDS FROM THE WEST THRU
THE WEEKEND. AT LOWER LEVELS...SFC LOW HAS DECOUPLED FROM THE TUTT
AND DEGRADED INTO A SURFACE TROUGH THAT WILL CONTINUE TO MOVE NORTH
OF THE AREA AND INTO THE SOUTHWESTERN ATLANTIC...MERGING WITH A
FRONTAL BOUNDARY BY SUN/MON. WINDS WILL BECOME MORE SOUTHERLY
TODAY...AND EAST-SOUTHEAST FOR THE NEXT SEVERAL DAYS AS SFC HIGH
ANCHORS OVER THE OPEN ATLANTIC WATERS.

DISCUSSION...AS SFC LOW MOVED SLOWLY TO THE WEST OVER THE
OFFSHORE ATLANTIC WATERS AND WINDS SHIFTED FROM NORTHERLY TO A
SOUTHERLY COMPONENT...SCATTERED SHOWERS DEVELOPED OVER THE
NORTHERN HALF OF PR EARLY IN THE AFTERNOON HOURS AND PASSING
SHOWERS PREVAILED ACROSS THE USVI DURING THE MORNING HOURS.
AT LEAST THRU EARLY THIS EVENING SCATTERED SHOWERS ARE POSSIBLE
ACROSS THE SAME AREAS AS STEERING WINDS CONTINUE MAINLY LIGHT WITH
A SOUTHERLY COMPONENT. SHOWERS WILL BE HEAVY AT TIMES. RAINFALL
ACCUMULATIONS BETWEEN 0.10-0.30 INCHES WERE OBSERVED WITH THE
EARLY ONSET OF AFTERNOON CONVECTION OVER THE NE SECTIONS OF PR.
ALSO...SHOWERS DEVELOPED OVER WESTERN PR AND WERE SLOWLY
STREAMING TO THE EAST-NORTHEAST.

UNDER A EAST TO SOUTHEASTERLY FLOW EXPECT LOW LEVEL MOISTURE TO
INCREASE SOMEWHAT THROUGH AT LEAST MONDAY. THEREFORE...SHOWERS
ARE EXPECTED FROM TIME TO TIME MAINLY ACROSS THE USVI AND THE
EAST/SOUTHEAST SECTIONS OF PUERTO RICO DURING THE OVERNIGHT/MORNING
HOURS...AND BETTER AFTERNOON CONVECTION OVER THE INTERIOR/NW
QUADRANT OF PR THRU THE WEEKEND...BUT SPECIALLY ON SUNDAY.

AS MID TO UPPER LEVEL RIDGE BUILDS FROM THE WEST DURING THE NEXT
FEW DAYS...THE TUTT WILL CONTINUE TO WEAKEN AND MOVE OVER THE OPEN
ATLANTIC. AS RIDGING BUILDS OVER...MOISTURE WILL THEN DROP ONCE
AGAIN WITH PWAT NEAR NORMAL VALUES THRU MUCH OF NEXT WEEK...WITH
SHOWERS OVER THE SAME AREAS BUT WITH LESS AREAL COVERAGE. SURFACE
HIGH WILL ANCHOR OVER THE CENTRAL/EASTERN ATLANTIC AND WARMER
TEMPERATURES ARE EXPECTED ALONG THE NORTH COAST OF PUERTO RICO
UNDER THE SOUTHEAST WIND FLOW.

AVIATION...SFC FLOW SHIFTING TO SW OR LGT AND VRBL THRU 06/12Z AS
LOW PRESSURE MOVES TO NW OF FA. FLOW FROM SSE WILL COMMENCE ARND
06/14Z WITH SEA BREEZE VARIATIONS AND INCREASE TO 10 TO 15 KT. MINOR
SHRA ACTIVITY WITH SOME HIR TRRN OBSCURED. SOUTHERLY COMPONENT
SWITCHES TO NORTHERLY ABV FL125 AND INCREASES TO NNW 40 KT BY
FL300.

MARINE...SMALL CRAFT ADVISORIES CONTINUE THROUGH AT LEAST 8 PM
AST FOR THE ATLANTIC COASTAL WATERS AND ANEGADA PASSAGE. OFFSHORE
BUOY 41043 INDICATED A NE SWELL BETWEEN 6-8 FEET AROUND 10
SECONDS...THIS WILL KEEP SEAS RELATIVE HIGH ACROSS THE OFFSHORE
ATLANTIC WATERS AND THEREFORE THE SMALL CRAFT ADVISORY WILL REMAIN
IN EFFECT THROUGH AT LEAST SUNDAY MORNING. ALSO...A MODERATE TO HIGH
RISK OF RIP CURRENTS WILL CONTINUE FOR MUCH OF THE NORTH FACING
BEACHES OF PR AND THE USVI THROUGH THE WEEKEND. SEAS BELOW 5 FEET
ARE EXPECTED ELSEWHERE AND LOWER JUST SOUTH OF THE ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  73  87  74  89 /  50  20  50  50
STT  73  85  75  87 /  30  20  60  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...HIGH RIP CURRENT RISK THROUGH SATURDAY AFTERNOON FOR CULEBRA-
     MAYAGUEZ AND VICINITY-NORTH CENTRAL-NORTHEAST-NORTHWEST-SAN
     JUAN AND VICINITY-SOUTHEAST-WESTERN INTERIOR.

VI...HIGH RIP CURRENT RISK THROUGH SATURDAY AFTERNOON FOR ST.
     THOMAS/ST. JOHN/ADJACENT ISLANDS.

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

&&

$$

27/11


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