Prognostic Meteorological Discussion
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FXCA20 KWBC 031034
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
633 AM EDT THU SEP 03 2015

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM SEP 03/06
UTC: BUILDING CELL OF THE SUBTROPICAL RIDGE CONTINUES TO DISPLACE
TUTT LOW TO THE EAST-SOUTHEAST. AS THE LOW RELOCATES...AN UPPER
CONVERGENT PATTERN ESTABLISHED ACROSS THE FORECAST AREA WHILE A
DRYER AIR MASS ADVECTED FROM THE EAST. AT LOW LEVELS...A FRESH
NORTHEASTERLY FLOW DOMINATES THE EASTERN CARIBBEAN...WITH WINDS OF
05-10KT. FARTHER UPSTREAM...A TROPICAL WAVE EXTENDS ALONG 45W/46W.

UPPER LOW IS TO MEANDER NEAR THE VIRGIN ISLES/EASTERN PUERTO RICO
OVER THE NEXT COUPLE OF DAYS. LATER DURING THE WEEKEND THE CUT OFF
LOW IS TO GRADUALLY WEAKEN WHILE LIFTING TO THE NORTHEAST. UNDER
INFLUENCE OF THIS TROUGH...AND THE RIDGE TO THE NORTH...STRONG CAP
INVERSION IS TO PERSIST THROUGH EARLY MORNING HOURS ON FRIDAY. ON
FRIDAY-SATURDAY...AS UPPER PATTERN STARTS TO EVOLVE...THE
INVERSION IS TO WEAKEN SOMEWHAT. THIS IS TO SLOWLY LIFT FROM 800
HPA EARLY THIS CYCLE TO 650/700 HPA DURING THE WEEKEND. AS LIGHT
TRADE WINDS ARE TO PREVAIL...THIS SHOULD ALLOW FOR LAND/SEA
BREEZES TO DEVELOP ACROSS THE FORECAST AREA. IN THIS PATTERN LIGHT
EARLY MORNING SHOWERS ARE TO AFFECT EASTERN PORTIONS OF PUERTO
RICO-VIRGIN ISLES...WHILE  SCATTERED CONVECTION DEVELOPS ACROSS
CENTRAL-WESTERN INTERIOR PORTIONS OF PR DURING THE AFTERNOON
HOURS. THIS IS TO GRADUALLY BECOME MORE ACTIVE THROUGH SATURDAY AS
CAP INVERSION LIFTS AND A LIGHTLY DEEPER/MOISTER AIR MASS ENTERS
THE FORECAST AREA. BOTH VERSIONS OF THE HRWRF SHOW LOCALIZED
MAXIMA OF 2-3 INCHES ALONG THE NORTHERN SLOPES OF THE
CORDILLERA...THIS SEEMS REASONABLE UNDER EVOLVING WEATHER
CONDITIONS.

TROPICAL WAVE REACHES THE FORECAST AREA EARLY ON MONDAY MORNING.
BUT LACKING UPPER LEVEL SUPPORT THIS IS TO ONLY FAVOR LIGHT TO
MODERATE RAINFALL AMOUNTS...WITH EMPHASIS ON THE LIGHT OVER THE
MODERATE.

SALMON...MS (ANTIGUA AND BARBUDA)
CABRERA...ONAMET (THE DOMINICAN REPUBLIC)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

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