Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 020215 AAA
AFDSJU

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1015 PM AST SUN MAR 1 2015

.UPDATE...SCATTERED SHOWERS ARE MOVING THROUGH THE NORTHEASTERN
HALF OF PUERTO RICO...AND...AT LEAST FOR NOW...ARE SKIRTING THE
U.S. VIRGIN ISLANDS. PATCHES OF MOISTURE WILL CONTINUE TO MOVE
THROUGH IN THE FRESH TO STRONG TRADE WINDS. NO CHANGES WERE MADE
TO THE NEAR TERM GRIDS THIS EVENING AND THEREFORE NO UPDATES WILL
BE NEEDED FOR THE ZONES OR GRIDDED PRODUCTS. DISCUSSION BELOW HOLDS.


&&

.AVIATION...VFR CONDS EXPECTED OVERNIGHT ACROSS THE LOCAL AREA
WITH ONLY QUICK PASSING SHOWERS CAUSING VCSH ACROSS MOST OF THE
LOCAL TERMINALS. WINDS WILL BE MAINLY FROM THE EAST TO E-NE AT
AROUND 10 KTS OVERNIGHT...INCREASING TO AROUND 15 KTS AND GUSTY WITH
SEA BREEZE VARIATIONS AFTER 02/13Z. SCT SHRA EXPECTED AFTER 02/10Z
ACROSS PR AND THE USVI...CAUSING AT LEAST VCSH....AND A SLIGHT
CHANCE OF TSRA ACROSS THE VICINITY OF TJMZ AFTER 02/16Z.


&&

.MARINE...NO CHANGES. SMALL CRAFT ADVISORIES IN WATERS EXPOSED TO
EAST WINDS. WINDS WILL CONTINUE TO DIMINISH SLIGHTLY TONIGHT AND
MONDAY...BUT 7-8 FOOT SEAS RETURN BY TUESDAY EXPOSED WATERS.

&&

.PREV DISCUSSION... /ISSUED 234 PM AST SUN MAR 1 2015/

SYNOPSIS...RIDGE ALOFT WILL COLLAPSE TONIGHT/EARLY MONDAY MORNING
AS UPPER LEVEL TROUGH AMPLIFIES ACROSS THE WESTERN AND CENTRAL
ATLANTIC INTO THE EASTERN CARIBBEAN. MIGRATORY SURFACE HIGHS NORTH
OF THE AREA WILL CONTINUE TO PROMOTE FRESH TO LOCALLY STRONG TRADE
WINDS OVER THE NEXT SEVERAL DAYS.

DISCUSSION...ISOLATED TO LOCALLY SCATTERED PASSING SHOWERS EMBEDDED
IN THE TRADES WERE OBSERVED ACROSS THE USVI AND EASTERN PUERTO RICO
IN THE MORNING AND EARLY AFTERNOON HOURS. WINDS WERE FROM THE EAST
AT 15 TO 20 KNOTS WITH COASTAL TEMPERATURES IN THE MID 80S.

PATCHES OF MOISTURE WILL CONTINUE TO MOVE ACROSS THE LOCAL AREA
THIS AFTERNOON AND WILL COMBINE WITH LOCAL EFFECTS TO RESULT IN
INTERVALS OF CLOUDINESS AND A FEW SHOWERS OVER THE LOCAL ISLANDS.
SHOWER ACTIVITY WILL BE FOCUSED ACROSS PORTIONS OF THE EASTERN
HALF OF PUERTO RICO AS WELL AS SW PR.

UNDER AMPLIFYING TROUGH ALOFT AND BREEZY CONDITIONS...TRADE WIND
SHOWERS WILL PREVAIL MONDAY WITH EVEN THUNDERSTORMS DEVELOPING
ACROSS SW PR IN THE AFTERNOON HOURS. LOCAL ISLANDS WILL BE UNDER
A CONVERGENT PATTERN ALOFT AS AFOREMENTIONED TROUGH AXIS RELOCATES
SOUTHEAST OF THE FORECAST AREA ON TUESDAY. THEREFORE TUESDAY
THROUGH AT LEAST SATURDAY...EXPECT A GENERALLY FAIR WEATHER
PATTERN WITH SEASONABLE TEMPERATURES UNDER EAST NORTHEAST WINDS
AND NEAR TO BELOW NORMAL PRECIPITABLE WATER. HOWEVER...PASSING
SHOWERS EMBEDDED IN THE TRADES CANT BE RULED OUT EACH DAY.

AVIATION...VFR CONDS AT ALL TAF SITE DURG THE ENTIRE PD...EXCEPT
FOR PASSING -SHRA/SHRA THAT MAY PRODUCE GUSTY WINDS AND BKN
CEILING BTWN FL020-FL060 OVER THE TAF SITES. ISOLD -SHRA/SHRA EN
ROUTE BTW PR AND NRN LEEWARDS. TONIGHT SCATTERED -SHRA/SHRA ARE
EXPECTED IN THE IN/AROUND TJSJ/TISX/TIST/TNCM/TKPK. RECENT 01/12Z
TJSJ UPPER AIR SOUNDING DATA SUGGEST WND MAINLY FM E BTW 15-26 KT
AND SHOULD PERSIST THRU FCST PD. WIND WKNG 14-22 KT LATE MON. NO
SIG AVN OPERATIONAL WX IMPACTS ATTM.

MARINE...FRESH TO LOCALLY STRONG TRADE WINDS WILL CONTINUE TO
GENERATE STEEP WAVES UP TO 7 FEET THROUGH MONDAY MORNING. ATLANTIC
SURFACE RIDGE WILL THEN WEAKEN SOMEWHAT MONDAY NIGHT WITH WINDS
RELAXING SOMEWHAT. WINDS STRENGTHEN AGAIN TUESDAY AFTERNOON INTO
THURSDAY AS A NEW AREA OF HIGH PRESSURE BUILDS ACROSS THE WESTERN
ATLANTIC.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  74  85  75  86 /  30  30  20  20
STT  73  85  74  86 /  30  30  20  20

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL NOON AST MONDAY FOR ANEGADA PASSAGE
     SOUTHWARD TO 17N-ATLC WATERS OF PUERTO RICO AND USVI FROM
     10NM TO 19.5N-COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10
     NM-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 UNTIL 1 PM AST MONDAY FOR CARIBBEAN WATERS
     OF PUERTO RICO FROM 10 NM TO 17N-MONA PASSAGE SOUTHWARD TO
     17N.

&&

$$

25/12




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