Prognostic Meteorological Discussion
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FXCA20 KWBC 051029
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
629 AM EDT TUE MAY 05 2015

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. MID/UPPER
LEVEL RIDGE REMAINS DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE
TROPICAL ATLANTIC INTO THE EASTERN CARIBBEAN. THIS CONTINUES TO
FAVOR A STRONG CAP INVERSION...WITH SHALLOW MOISTURE CONFINING TO
ATMOSPHERE BELOW 800 HPA. AT LOW LEVELS...RIDGE ALOFT SUSTAINS
BROAD RIDGE PATTERN ACROSS THE CENTRAL-EASTERN ATLANTIC. THIS
FAVORS A TIGHT GRADIENT ACROSS THE TROPICAL ATLANTIC INTO THE
EASTERN CARIBBEAN...WITH A TRADE WINDS SURGE EVIDENT ON THE IR/VIS
IMAGES. FURTHERMORE...THE METEOSAT RGB PRODUCT SHOWS THE LEADING
EDGE OF A DENSE SAL CROSSING 55W/56W EARLY THIS MORNING. THIS IS
EXPECTED TO ENTER THE ISLAND CHAIN/EASTERN CARIBBEAN LATER THIS
EVENING.

MID/UPPER RIDGE PATTERN IS FORECAST TO PREVAIL WELL INTO THE
MEDIUM RANGE PERIOD. ONLY CHANGE EXPECTED OVER THE NEXT FEW DAYS
IS AN INCREASE IN HIGH CLOUDS DURING THE DAY ON WEDNESDAY...WHEN
DENSE CI/CS SHIELD IS TO ENVELOP THE FORECAST AREA. THIS IS
EXPECTED TO PERSIST THROUGH THE END OF THE WEEK. THE INCREASE IN
CLOUD COVER WILL DELAY ONSET OF SEA BREEZE CONVERGENCE ACROSS THE
FORECAST AREA. THIS WILL COMBINE WITH SAL DUST ENTERING THE
ISLANDS TO REDUCE CHANCES FOR CONVECTION TO NEARLY NIL FROM
WEDNESDAY AND ONWARD THROUGH THE END OF THE WEEK. TODAY MIGHT BE
THE LAST DAY OF SOME CONVECTION DEVELOPING ACROSS THE LARGER
ISLANDS. IN A SOUTHEASTERLY STEERING FLOW CONVECTIVE ACTIVITY...IF
ANY...IS TO LIMIT TO NORTHWEST PORTIONS OF PUERTO RICO.

CRAIG...TTMS (TRINIDAD AND TOBAGO)
SAMUEL...MDS (SURINAME)
DAVISON...WPC (USA)
$$




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