Prognostic Meteorological Discussion
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000
FXCA20 KWBC 281205
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
805 AM EDT THU AUG 28 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. TUTT CENTERS
AT 20N 60W AND EXTENDS AN AXIS ZONALLY INTO JUST NORTH OF THE
DOMINICAN REPUBLIC. MOST ACTIVITY HOWEVER CONCENTRATES WELL TO THE
SOUTH ACROSS THE CENTRAL AND SOUTHERN CARIBBEAN...IN ASSOCIATION
WITH A TROPICAL WAVE. THE LATTER EXTENDS FROM THE CORO PENINSULA
INTO REGIONS JUST SOUTH OF THE VIRGIN ISLANDS. ANOTHER TROPICAL
WAVE FOLLOWS. THE LATTER IS LESS DEFINED IN TERMS OF THE WIND
FIELD...AND IS INTERACTING WITH UPPER AIR SYSTEMS.

TUTT TO THE NORTH IS FORECAST TO SLOWLY RETROGRESS THROUGH
SATURDAY MORNING. FIRST TROPICAL WAVE IS EXITING THE REGION...YET
PLUME OF PRECIPITABLE WATER ASSOCIATED WITH THIS WAVE WILL GRAZE
THE SOUTHERN COAST OF PUERTO RICO AIDING THE DEVELOPMENT OF
DIURNAL CONVECTION. STRONGEST STORMS ARE EXPECTED ALONG THE
CORDILLERA AND WESTERN PUERTO RICO WITH MAXIMUM ACCUMULATIONS OF
15-20MM/DAY.

GLOBAL MODEL SOLUTIONS REGARDING NEXT PERTURBATION CONTINUE
DIVERGING. THE GFS HAS THE STRONGEST PERTURBATION AND THE
NORTHERNMOST TRACK. THE ECMWF AND UKMET ARE MUCH MORE CONSERVATIVE
WITH THIS SYSTEM AND THEIR SOLUTIONS ARE SLIGHTLY CLOSER TOGETHER
NOW. THE LATTER SHOWS A SOUTHERN TRACK THAT BRINGS A WEAK WAVE
WESTWARD ACROSS THE CENTRAL/SOUTHERN CARIBBEAN...WITH LIMITED
EFFECTS ON PRECIPITATION. UNCERTAINTY STILL REMAINS.
REGARDLESS...IT DOES NOT APPEAR THAT ACCUMULATIONS WITH THIS
SYSTEM WILL BE EXTREME. THE GFS...BEING THE WETTEST
SOLUTION...SUGGEST ISOLATED MAXIMA OF 25-50MM/DAY MOSTLY NORTH OF
THE ISLANDS OVER OPEN WATERS OF THE ATLANTIC. THIS PARTICULAR CASE
REQUIRES SPECIAL ATTENTION TO COMING MODEL SOLUTIONS. GIVEN
CURRENT TREND THOUGH...IT APPEARS THAT IF ACCUMULATIONS OVER 25MM
OCCUR...THEY WILL BE GENERALLY ISOLATED AND LINKED TO THE DIURNAL
DISTRIBUTION OF CONVECTION...AS TRADE WINDS ARE EXPECTED TO
DECREASE IN SPEED ONCE THIS PERTURBATION ARRIVES.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
GALVEZ...WPC (USA)
$$




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