Post by cycloneye on Mar 23, 2016 3:57:50 GMT -6
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
452 AM AST WED MAR 23 2016
.SYNOPSIS...A MID TO UPPER LEVEL RIDGE WILL HOLD ACROSS THE
FORECAST AREA THROUGH THE UPCOMING WEEKEND. THIS FEATURE WILL
THEN ERODE AS UPPER LEVEL PERTURBATIONS MOVE NORTH OF THE AREA.
BUILDING SURFACE HIGH ACROSS THE WESTERN ATLANTIC WILL CONTINUE
TO TIGHTEN THE LOCAL PRESSURE GRADIENT...BRINGING MODERATE TO
FRESH TRADE WINDS ACROSS THE LOCAL ISLANDS. A SURFACE FRONT
WILL CONTINUE TO DISSIPATE NORTH OF THE AREA.
&&
.DISCUSSION...PARTLY CLOUDY SKIES PREVAILED ACROSS THE LOCAL
ISLANDS OVERNIGHT AND EARLY THIS MORNING...WITH A FEW PASSING
SHOWERS OBSERVED ACROSS THE NORTH AND EAST COASTAL AREAS. WINDS
WERE LIGHT AND VARIABLE WITH TEMPERATURES IN THE MID 70S AT LOWER
ELEVATIONS.
A GENERALLY FAIR AND MAINLY STABLE WEATHER PATTERN WILL CONTINUE
TO PREVAIL ACROSS THE LOCAL ISLANDS THROUGH THE UPCOMING WEEKEND
UNDER A MID TO UPPER LEVEL RIDGE PATTERN AND ASSOCIATED CAP
INVERSION. ALTHOUGH MID LEVELS WILL REMAIN DRY THE NEXT SEVEN
DAYS...PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADES WILL
CONTINUE TO MOVE ACROSS THE AREA FROM TIME TO TIME. THIS WILL
RESULT IN PASSING SHOWERS ACROSS WINDWARD AREAS IN THE EVENING AND
MORNING HOURS...FOLLOWED BY LIMITED AFTERNOON CONVECTION EACH DAY.
WINDS WILL BECOME MORE EASTERLY...AS SURFACE HIGH PRESSURE CONTINUES
TO BUILD NORTH OF THE AREA...THEREFORE COASTAL TEMPERATURES ALONG
THE NORTHERN SLOPES WILL RETURN TO THE MID TO UPPER 80S
AS RIDGE ALOFT ERODES LATE THE UPCOMING WEEKEND AND EARLY NEXT
WORKWEEK...LOW LEVEL MOISTURE IS EXPECTED TO POOL ACROSS THE AREA
AND THEREFORE THERE IS A BETTER CHANCE FOR TRADE WIND SHOWERS AND
AFTERNOON CONVECTION. IN FACT...LATEST GUIDANCE INDICATED LOW
LEVEL MOISTURE STEADILY INCREASING MONDAY THROUGH THE END OF NEXT
WEEK.
&&
.AVIATION...MAINLY VFR CONDITIONS EXPECTED ACROSS ALL TERMINALS
DURING THE NEXT 24 HOURS. LIGHT PASSING SHOWERS ACROSS THE LOCAL
WATERS COULD REACH THE LEEWARD/USVI TERMINALS CAUSING BRIEF VCSH.
SURFACE WINDS WILL BECOME FROM THE EAST AT 10-15 KNOTS WITH SEA
BREEZE VARIATIONS AND OCCASIONAL GUSTS AFT 23/13Z. SHRA DEVELOPING
OVER PR AFTER 23/16Z MAY CAUSE VCSH AT TJMZ/TJBQ AND BRIEFLY AT
TJSJ.
&&
.MARINE...CHOPPY SEAS EXPECTED AS WINDS INCREASE ACROSS THE LOCAL
WATERS. THEREFORE SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION
DUE TO SEAS BETWEEN 4 AND 6 FEET WITH OCCASIONAL SEAS UP TO 8 FEET
AND EASTERLY WINDS 15 TO 20 KNOTS. THERE IS A MODERATE RISK OF RIP
CURRENTS ALONG THE ATLANTIC COASTLINE.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 87 76 / 20 40 30 30
STT 86 76 86 76 / 20 40 30 30