Post by cycloneye on Jun 11, 2015 4:09:30 GMT -6
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
539 AM AST THU JUN 11 2015
.SYNOPSIS...LOW LEVEL MOISTURE FROM THE CIRCULATION AT 700 MB OUT
OF AN OLD FRONTAL BOUNDARY TO OUR NORTH WILL CONTINUE UNTIL
TONIGHT. A MID TO UPPER LEVEL RIDGE WILL CONTINUE OVER THE LOCAL
REGION DURING THE NEXT FEW DAYS. A TROPICAL WAVE IS EXPECTED TO
MOVE SOUTH OF THE LOCAL AREA FRIDAY INTO SATURDAY. A SURFACE HIGH
PRESSURE ANCHORED OVER THE NORTH ATLANTIC IS EXPECTED TO MAINTAIN
LIGHT TO MODERATE EASTERLY TRADE WINDS ACROSS THE NORTHEASTERN
CARIBBEAN. AN AREA OF SAHARAN AIR IS EXPECTED TO REACH THE LOCAL
AREA ON SUNDAY.
.DISCUSSION...SATELLITE IMAGERY SHOWED A SURGE OF DEEP MOISTURE
THAT HAS BEEN ADVECTED ACROSS THE REGION OVERNIGHT AND EARLY IN
THE MORNING HOURS. THE DOPPLER WEATHER RADAR HAS BEEN DETECTING
FINELY SCATTERED TRADE WIND SHOWERS MAINLY ACROSS THE LOCAL
WATERS... EASTERN PUERTO RICO AND THE USVI.
THIS AFTERNOON...THE COMBINATION OF AVAILABLE MOISTURE WITH THE
LOCAL EFFECTS AND DIURNAL HEATING IS EXPECTED TO AID IN THE
DEVELOPMENT OF AFTERNOON CONVECTION MAINLY OVER THE CORDILLERA
CENTRAL AND WESTERN PUERTO RICO...HOWEVER A FEW SHOWERS ARE
EXPECTED ELSEWHERE.
A TROPICAL WAVE IS EXPECTED TO MOVE SOUTH OF THE LOCAL AREA
BETWEEN FRIDAY AND SATURDAY. THE MODEL GUIDANCE CONTINUES TO
SUGGEST THE ARRIVAL OF ENOUGH MOISTURE AND INSTABILITY TO RESULT
IN AN INCREASE IN THE AFTERNOON SHOWER/THUNDERSTORM ACTIVITY.
AFTER THAT WAVE...ANOTHER AREA OF SAHARAN AIR IS EXPECTED TO MOVE
ACROSS THE EASTERN CARIBBEAN ON SUNDAY AND INTO THE EARLY PART OF
NEXT WEEK BRINGING A DRIER AND WARMER TREND WITH CONSIDERABLE
SUSPENDED DUST.
THE LOCAL GFS MODEL IS STILL SUGGESTING A BETTER CHANCE OF
SHOWERS AS A TROPICAL WAVE IS EXPECTED TO BRING A SURGE OF
TROPICAL MOISTURE AS IT MOVES CLOSER TO THE LOCAL ISLANDS ON
TUESDAY AND WEDNESDAY. AT THIS TIME...MODELS ARE SHOWING A BETTER
AGREEMENT IN THE TIMING OF ITS ARRIVAL.
&&
.AVIATION...PASSING SHRA BUT MAINLY VFR. BRIEF MVFR PSBL
TNCM...TKPK. MID LEVEL DRYING TO OCCUR AFT 11/18Z...BUT SHRA/TSRA
WILL DEVELOP AFT 11/16Z OVER INTERIOR AND WRN PR WITH MVFR CONDS AND
MTN OBSCURATIONS INCLUDING TJBQ AND TJMZ...IMPRVG AFT 12/02Z. WINDS
ALF E TO ESE 10 TO 20 KT UP THRU FL240. WINDS ABV FL280 WNW UP TO 30
KT.
&&
.MARINE...
SEAS BETWEEN 2 AND 5 FEET AND WINDS AT 10 TO 15 KNOTS ARE
EXPECTED ACROSS MOST OF THE LOCAL WATERS. SMALL CRAFT OPERATORS
SHOULD EXERCISE CAUTION ACROSS THE NORTHERN...SOUTHERN AND
SOUTHWESTERN COASTAL WATERS DUE TO WINDS BETWEEN 15 AND 20 KNOTS.
WINDS AND SEAS COULD BE HIGHER IN AND AROUND THE SHOWER ACTIVITY.
PLEASE REFER TO LATEST COASTAL WATERS FORECAST ISSUED BY THE
NATIONAL WEATHER SERVICE IN SAN JUAN PR FOR ADDITIONAL
INFORMATION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 90 78 / 30 20 30 30
STT 88 79 89 80 / 30 30 30 30