Prognostic Meteorological Discussion
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FXCA20 KWBC 221048
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
647 AM EDT FRI AUG 22 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. A STRONG
TROPICAL WAVE ENTERED THE FORECAST AREA EARLY THIS MORNING. MOST
ACTIVE CONVECTION IS DEVELOPING JUST WEST OF THE TROUGH
AXIS...WITH ACTIVITY SPLITTING BETWEEN THE CARIBBEAN AND ATLANTIC
WATERS OF PUERTO RICO. THIS WAVE IS INDUCING THE NORTHWARD
MODULATION OF THE ITCZ ACROSS THE FRENCH ISLANDS...WITH A DEEP
MOIST PLUME TRAILING AS THE WAVE PULLS AWAY. ALTHOUGH THE WAVE IS
TO QUICKLY MOVE ACROSS PUERTO RICO...HIGH MOISTURE CONTENT IS
EXPECTED TO PERSIST THROUGH SUNDAY MORNING...WITH MODELS
PROJECTING PWAT OF 50-60MM TO POOL ACROSS THE FORECAST AREA.

DURING THE DAY TODAY EXPECTING CONVECTION TO DEVELOP IN TWO
ROUNDS...THE ONE EARLY THIS MORNING TO ACCOMPANY WAVE PASSAGE AND
ANOTHER THIS AFTERNOON AS ENHANCED BY DIURNAL HEATING. THE FIRST
IS TO GENERALLY FAVOR WIDESPREAD CONVECTION...WHILE THE LATTER IS
TO BECOME MORE LOCALIZED OVER NORTHWEST PORTIONS OF THE ISLAND AS
THE WINDS VEER TO THE SOUTHEAST. RAINFALL MAXIMA IS TO PEAK AT 2-4
INCHES. ON SATURDAY...IN A LONG FETCH SOUTHEASTERLY
FLOW...CONVECTION BUILDING ACROSS SAINT CROIX IS TO THEN ADVECT TO
EASTERN PUERTO RICO...TO SUSTAIN SCATTERED CONVECTION BETWEEN
CEIBA-PATILLA DURING LATE MORNING/EARLY AFTERNOON HOURS. OTHER
ACTIVITY IS EXPECTED ALONG THE CORDILLERA CENTRAL...WITH THE MOST
INTENSE TO CLUSTER ACROSS NORTH-CENTRAL TO NORTHWESTERN PORTIONS
OF PUERTO RICO (BETWEEN DORADO AND RINCON). ACROSS SAINT CROIX TO
SOUTHEAST PR EXPECTING MAXIMA OF 1-3 INCHES...WHILE OVER NORTHWEST
PUERTO RICO MAXIMA WILL LIKELY EXCEED 3 INCHES.

UPPER LEVEL RIDGE NORTH OF THE ISLANDS IS TO THEN STEER A
TUTT/TUTT LOW ACROSS THE LESSER ANTILLES LATER ON SUNDAY...WITH
VORTEX TO THEN TRACK ACROSS THE EASTERN CARIBBEAN JUST SOUTH OF
THE FORECAST AREA. AT MID LEVELS THIS IS TO SUSTAIN A FAIRLY
STRONG VORTEX ACROSS THE VIRGIN ISLES/EASTERN PUERTO RICO EARLY ON
MONDAY. AS THE TUTT ENTERS THE BASIN...MODELS SHOW A MID/UPPER
CONVERGENT PATTERN ESTABLISHING DURING THE DAY ON SUNDAY...
FAVORING A SUBSIDENCE CAP AND RAPID DRYING OF THE MID/UPPER
LEVELS. THIS IS TO PERSIST THROUGH MONDAY. THE MID/UPPER LEVEL
VORTEX IS TO THEN FAVOR THE EROSION OF THE CAP INVERSION...WITH
MOISTURE TO GRADUALLY SURGE ON TUESDAY-WEDNESDAY FAVORING
SCATTERED SHOWERS ACROSS THE VI/EASTERN PUERTO RICO.

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

$$




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