and
will be the pattern for the final days of the year and the first days of 2012.AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
457 AM AST THU DEC 29 2011
.SYNOPSIS...AT UPPER LEVELS...RIDGING FROM THE SOUTH DOMINATES THE
EASTERN CARIBBEAN...PUERTO RICO AND THE U.S. VIRGIN ISLANDS
THROUGH EARLY NEXT WEEK.
AT MID LEVELS...HIGH PRESSURE NORTHEAST OF THE AREA BUILDS TO THE
WEST TO CUBA OVER THE WEEKEND THEN RETURNS TO THE LOCAL AREA. THE
MID LEVELS ARE GENERALLY VERY DRY UNTIL LATER NEXT WEEK.
AT LOWER LEVELS...MODERATE HIGH PRESSURE REMAINS IN THE
NORTHEASTERN ATLANTIC AND MAINTAINS A RIDGE ACROSS THE WESTERN
ATLANTIC BETWEEN 20 AND 30 DEGREES NORTH THROUGH EARLY NEXT WEEK
WHEN WEAK TROUGHINESS APPROACHES FROM THE WEST. PATCHES OF LOW-
LEVEL MOISTURE MOVE THROUGH THE FORECAST AREA FROM THE EAST
THROUGHOUT THE NEXT 7 DAYS.
&&
.DISCUSSION...SHOWERS IN THE FORECAST AREA INCREASED OVER THE
ATLANTIC AND CARIBBEAN WATERS THROUGHOUT THE NIGHT...BUT LESS
SHOWER ACTIVITY MOVED ONSHORE COMPARED WITH WEDNESDAY NIGHT.
MODELS SHOW...AND MIMIC PRODUCT CONFIRMS...AN AREA OF MOISTURE
MOVING IN FROM THE EAST AND ARRIVING LATER TODAY AND TONIGHT.
AREAS OF MOISTURE WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS OVER THE EASTERN TWO THIRDS OF PUERTO RICO AND TO A LESSER
EXTENT THE U.S. VIRGIN ISLANDS FRIDAY THROUGH SUNDAY IN
PERSISTENT EASTERLY FLOW. THIS WILL PLACE MOST OF THE RAINFALL ON
THE EASTERN SLOPES OF THE LUQUILLO RANGE. AMOUNTS WILL BE
INSUFFICIENT FOR FLOODING BUT WILL MAINTAIN SOIL MOISTURE AT HIGH
LEVELS IN THOSE AREAS. SCATTERED SHOWERS CONTINUE BEYOND 7
DAYS...BUT MODELS SHOW NO FRONTS MOVING INTO THE AREA FOR AT LEAST
ANOTHER 10 DAYS DUE TO THE PERSISTENT RIDGE OUT OF THE HIGH IN THE
NORTHEAST ATLANTIC.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE LOCAL ISLANDS AND
AT ALL TAF SITES DURING THE NEXT 24 HOURS. HOWEVER...TEMPO MVFR
CONDITIONS AND LOCAL MOUNTAIN OBSCURATIONS ARE POSSIBLE IN ISOLATED
SHOWERS ACROSS TJPS AND TJMZ...AND SCATTERED SHOWERS ELSEWHERE.
EXPECT EAST TO EAST SOUTHEAST WINDS AT 5 TO 20 KTS FROM THE SURFACE
TO 10 KFT DURING THE DAY.
&&
.MARINE...SEAS OF 8.5 TO 10 FEET WERE INDICATED EARLY THIS MORNING AT
BUOY 41043 TO OUR NORTH WITH PERIODS OF 13 TO 15 SECONDS. MOST OF
THE SEA HEIGHTS ARE DUE TO SWELL. THIS SWELL IS EXPECTED IN THE
NEAR SHORE WATERS AROUND 8 AM AST REACHING AT LEAST 7 FEET. THIS
WOULD CAUSE BREAKERS OF 10 TO 16 FEET GIVEN PERIODS UP TO 16
SECONDS. THEREFORE A HIGH SURF ADVISORY HAS BEEN ISSUED. MODELS
UNDER-FORECAST THIS SWELL EVENT...BUT IT PEAKED LATER THAN
FORECAST AS WELL. EXPECT THAT SEAS WILL REMAIN HIGH...HENCE A
SMALL CRAFT ADVISORY FOR MOST WATERS IN THE AREA THROUGH THE
WEEKEND. BUT THE HIGH NORTH SWELL MAY LAST ONLY FOR A SHORT WHILE
SO HAVE LIMITED HIGH SURF ADVISORY TILL THIS EVENING PENDING
OBSERVATIONS AT THE OUTER BUOY. WINDS WILL INCREASE SOMEWHAT
TODAY AND TONIGHT...BUT BEING FROM THE EAST...SEAS GENERATED WILL
NOT IMPACT THE ISLANDS` COASTS AS MUCH.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 82 72 81 72 / 50 60 60 60
STT 85 74 85 75 / 30 50 50 40










