Post by cycloneye on Feb 21, 2016 4:28:09 GMT -6
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
507 AM AST SUN FEB 21 2016
.SYNOPSIS...AT UPPER LEVELS...A WEAK TROUGH WILL PASS THROUGH THE
AREA OVERNIGHT TONIGHT THEN A RIDGE WILL BUILD OVER THE AREA BY
TUESDAY AND CONTINUE THROUGH EARLY THE FOLLOWING WEEK.
AT MID LEVELS...AFTER A WEAK TROUGH PASSAGE TONIGHT...HIGH
PRESSURE WILL DOMINATE THE CARIBBEAN IN GENERALLY WEST OR
NORTHWEST FLOW. MID LEVELS WILL BE QUITE DRY EXCEPT FOR MONDAY
EVENING OVER NORTHERN PUERTO RICO AND THURSDAY NIGHT OVER
NORTHWEST PUERTO RICO WHEN PATCHES OF MODERATE MOISTURE WILL
PRESENT THEMSELVES.
AT LOWER LEVELS...HIGH PRESSURE NORTH OF THE AREA IN THE WESTERN
ATLANTIC OCEAN WILL CONTINUE TO MOVE EAST NORTHEAST. A WEAK TROUGH
EAST OF THE AREA WILL MOVE OVERHEAD MONDAY MORNING. HIGH PRESSURE
WILL THEN SPREAD ITS INFLUENCE OVER THE AREA FROM THE NORTHEAST
ATLANTIC WITH MODERATE EAST SOUTHEAST TRADE WINDS AND PATCHY
MOISTURE.
&&
.DISCUSSION...NORTHEAST FLOW CONTINUED SLIGHTLY ABATED FROM THE
PREVIOUS NIGHT. FINE SHOWERS EMBEDDED IN THE FLOW MOVED ACROSS THE
ATLANTIC WATERS AND ONSHORE IN PUERTO RICO AND THE NORTHERN U.S.
VIRGIN ISLANDS DISSIPATING NO MORE THAN 10 TO 15 MILES INLAND.
SHOWERS ARE EXPECTED TO CONTINUE DURING THE DAY BUT DRIER AIR WILL
CAUSE THEM TO DIMINISH. SHOWERS MAY RE-INTENSIFY OVERNIGHT AGAIN
TONIGHT BUT WILL NOT TRAVEL FARTHER ONSHORE TONIGHT THAN THEY DID
LAST NIGHT. AS THE LOW LEVEL TROUGH MOVES TO THE CENTER OF PUERTO
RICO OVERNIGHT WINDS WILL TURN MORE EASTERLY. MOISTURE ALSO
INCREASES TODAY THROUGH TUESDAY AND WEDNESDAY...BUT WITH MOISTURE
BEING SHALLOW...SHOWER ACTIVITY WILL BE LIMITED BY THE DRY AIR
ALOFT THROUGH THE PERIOD. AFTER WEDNESDAY...SHOWER ACTIVITY WILL
AGAIN TAPER OFF UNTIL NEXT WEEK BEGINS.
&&
.AVIATION...UNDER THE PREVAILING WIND FLOW...CLOUDS WITH
EMBEDDED SHOWERS ARE EXPECTED TO AFFECT TJSJ/TJBQ/TIST AND
TISX/TNCM/TKPK FROM TIME TO TIME. DURING THE AFTERNOON SHRA ARE
EXPECTED TO DEVELOP TO THE SOUTH OF THE CORDILLERA TO AFFECT TJPS
ALSO. SHRA WITH GUSTY WINDS CAN BE EXPECTED DURING THE FCST
PERIOD. SFC WINDS WILL CONTINUE MAINLY FROM THE NORTHEAST AT 5 TO
15 KT INCREASING AFT 21/13Z AT 10 TO 20 KTS WITH HIGHER GUSTS.
&&
.MARINE...SEAS ARE NOW FORECAST TO PEAK AT THE OUTER BUOY AROUND
21/08Z AND THIS WILL MEAN AN ARRIVAL OF THE BEST WAVES THIS
EVENING. HIGH SURF ADVISORIES WILL CONTINUE ON THE NORTHERN COAST
OF PUERTO RICO WHERE WAVES WILL RANGE FROM 10 TO 13 FEET WITH
OCCASIONAL WAVES UP TO 14 FEET IN SOME AREAS. WITH THE LARGE
WAVES WILL ALSO COME THE HIGH RISK OF RIP CURRENTS ON MOST NORTH
AND EAST FACING BEACHES. MARINERS WILL ALSO FIND SMALL CRAFT
ADVISORIES UP FOR THE ATLANTIC WATERS AND PASSAGES. THE SMALL
CRAFT ADVISORY IN THE OUTER CARIBBEAN IS MAINLY DUE TO SEAS IN
THE ANEGADA PASSAGE. HIGH SURF SHOULD ABATE BY MONDAY NIGHT...BUT
THE SMALL CRAFT ADVISORIES IN THE OUTER ATLANTIC WATERS AND THE
ANEGADA PASSAGE ARE EXPECTED TO BE IN FORCE THROUGH THURSDAY AS
SYSTEMS IN THE ATLANTIC CONTINUE TO SEND NORTH AND NORTHEAST SWELL
INTO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 83 72 87 73 / 40 40 40 40
STT 84 73 85 77 / 30 50 30 40