Prognostic Meteorological Discussion
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FXCA20 KWBC 051112
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
612 AM EST MON DEC 05 2016

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM DEC 05/06
UTC: A MID LEVEL HIGH OVER CUBA ANCHORS A RIDGE ACROSS THE
NORTHERN CARIBBEAN ISLES/WESTERN ATLANTIC. OVER THE NEXT FEW DAYS
THE HIGH IS TO MEANDER EAST...MOVING NORTH OF THE LEEWARD ISLES
EARLY ON FRIDAY MORNING. MEANWHILE...THIS IS TO SUSTAIN A CAP
INVERSION THAT IS FORECAST TO GRADUALLY STRENGTHEN THROUGH TUESDAY
EVENING/WEDNESDAY MORNING. AT LOW LEVELS...BROAD RIDGE TO THE
NORTH FAVORS A FRESH NORTHEASTERLY FLOW. THIS IS TO ENHANCE
MOISTURE CONVERGENCE ACROSS WESTERN INTERIOR/SOUTHWEST PORTIONS OF
PUERTO RICO EARLY THIS AFTERNOON...WITH ELEVATED POTENTIAL FOR
MODERATE RAINFALL AMOUNTS AS SUGGESTED BY HIGH RESOLUTION MODEL
GUIDANCE.

FURTHERMORE...A WANING FRONT LIES TO THE NORTH OF THE ISLANDS.
THROUGH TUESDAY MORNING THE FRONT IS TO MEANDER SOUTH ACROSS THE
VI-PUERTO RICO...WHERE IT IS EXPECTED TO RAPIDLY FRONTOLIZE. IN A
VERY STRONG MID/UPPER CONVERGENT PATTERN... THIS IS TO ONLY FAVOR
LIGHT SHALLOW CONVECTION AS IT MOVES ACROSS THE FORECAST
AREA...WITH MOST ACTIVE LIKELY TO LIMIT TO EL YUNQUE RAINFOREST
AND SOUTHWEST PORTIONS OF PUERTO RICO. FAIR WEATHER CONDITIONS
WILL THEN PREVAIL THROUGH FRIDAY MORNING. DURING THIS
PERIOD...CONVECTION...IF ANY...WILL LIMIT TO EARLY MORNING SHOWERS
OVER EASTERN PORTIONS OF PUERTO RICO-USVI AND ACROSS WESTERN
INTERIOR PORTIONS OF PUERTO RICO IN THE AFTERNOON.

DURING THE MEDIUM RANGE PERIOD...AN AMPLIFYING POLAR TROUGH MOVES
ACROSS NORTH AMERICA. AS IT REACHES THE EASTERN SEABOARD LATER IN
THE WEEK THE POLAR TROUGH WILL PRESS AGAINST THE SUBTROPICAL RIDGE
TO THE EAST. THIS WILL LEAD TO AFOREMENTIONED
DISPLACEMENT/RELOCATION OF THE RIDGE PATTERN AND GRADUAL EROSION
OF THE TRADE WINDS CAP. THIS WILL COINCIDE WITH ARRIVAL OF AN
EASTERLY WAVE ON FRIDAY TO FAVOR AN INCREASE IN CONVECTION ACROSS
THE ENTIRE FORECAST AREA.

JIMENEZ...IMN (COSTA RICA)
MIRANDA...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)

$$





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