Prognostic Meteorological Discussion
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FXCA20 KWBC 231849
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
248 PM EDT THU OCT 23 2014

LARGE UPPER TROUGH CENTERS OVER THE EASTERN UNITED STATES AND IS
SUSTAINING A SURFACE FRONT INTO SOUTHERN FLORIDA AND THE
SOUTHEASTERN GULF OF MEXICO. AN UPPER SHORT WAVE TROUGH FOLLOWS TO
ITS SOUTHWEST...EXTENDING FROM ALABAMA INTO THE GULF OF CAMPECHE.
THIS TROUGH IS INTERACTING WITH DISORGANIZED SURFACE LOWS OVER
YUCATAN AND CUBA. THESE LOWS ARE ACCOMPANIED BY HIGH CONVECTIVE
INSTABILITY...AND ARE THUS LEADING TO HEAVY RAINFALL IN AREAS
STRETCHING FROM NORTHERN CENTRAL AMERICA/YUCATAN INTO
CUBA/BAHAMAS. MODELS CONTINUE UNCERTAIN REGARDING THE EVOLUTION OF
THIS SYSTEM...BUT IT APPEARS THAT THE SHORT WAVE TROUGH WILL
INTERACT WITH THE SURFACE LOW AND HELP IT TO TRACK NORTHEASTWARD
ALONG THE BAROCLINIC BOUNDARY...PLACING A BROAD TROUGH ACROSS
CENTRAL CUBA BY THURSDAY EVENING AND A LOW JUST EAST OF THE
CENTRAL BAHAMAS BY FRIDAY EVENING TO THEN EXIT INTO THE NORTH
ATLANTIC. ANOTHER SURFACE LOW IS FORECAST TO MEANDER BETWEEN
SOUTHEASTERN YUCATAN ON THURSDAY TO THE SOUTHWESTERN GULF OF
HONDURAS BY SATURDAY. BOTH SYSTEMS WILL BE IMPORTANT FOCI FOR DEEP
CONVECTION AND HEAVY PRECIPITATION. THROUGH EARLY
FRIDAY...EXPECTING LARGEST RAINFALL AMOUNTS ACROSS MOST OF CUBA
AND THE BAHAMAS TO REACH 35-70MM/DAY AND MAXIMA OF 150-200MM.
OTHER REGION OF HEAVY RAINFALL WILL BE SOUTHEASTERN MEXICO INTO
GUATEMALA/BELIZE WITH AMOUNTS OF 25-50MM/DAY AND MAXIMA OF
75-125MM. ACROSS THE CAYMAN ISLANDS AND NORTHERN
YUCATAN...EXPECTING MAXIMA OF 25-50MM. BY FRIDAY INTO EARLY
SATURDAY...EXPECTING LARGEST AMOUNTS OVER THE BAHAMAS AND OVER THE
GULF OF HONDURAS WITH AMOUNTS OF 50-75MM/DAY AND MAXIMA OF
150-200MM. ACROSS CUBA EXPECTING AMOUNTS OF 20-40MM/DAY AND MAXIMA
OF 75-150MM. ACROSS CENTRAL/SOUTHERN GUATEMALA EXPECTING MAXIMA OF
25-50MM. BY SATURDAY INTO EARLY SUNDAY...EXPECTING LARGEST AMOUNTS
ACROSS NORTHEASTERN HONDURAS WITH MAXIMA OF 75-125MM/DAY. ACROSS
CUBA AND THE SOUTHEASTERN BAHAMAS AND THE CAYMAN ISLANDS EXPECTING
MAXIMA OF 25-50MM.

ACROSS COLOMBIA...EXPECTING A GRADUAL INCREASE IN CONVECTION
ACROSS THE WESTERN TIER ASSOCIATED WITH AN INCREASE IN THE
LOW-LEVEL WESTERLIES ACROSS THE GULF OF PANAMA. AMOUNTS IN
CONVECTION ARE TO INCREASE GRADUALLY TO MAXIMA OF 20-40MM/DAY.

OTHER AREA OF INTEREST ARE THE WINDWARD ISLANDS AND NORTHEASTERN
SOUTH AMERICA. A TROPICAL WAVE IS INTERACTING WITH A TUTT THAT
EXTENDS ACROSS THE CENTRAL LESSER ANTILLES INTO THE EASTERN
CARIBBEAN. MODELS SHOW TUTT PERSISTING AND BECOMING FULLY DETACHED
FROM THE WESTERLIES TO THE NORTH. THIS WILL LIMIT THE COLD AIR
INFUSION INTO THE SYSTEM AND START WEAKENING IT...GRADUALLY
REDUCING ITS EFFECTS ON CONVECTION. AT LOW-LEVELS...TROPICAL WAVE
WILL CONTINUE PROGRESSING INTO THE SOUTHEASTERN CARIBBEAN AS IT IS
CROSSING THE ARC OF THE ANTILLES EARLY ON THURSDAY. WAVE
CONVECTION WILL HOWEVER ENTER THE CONVERGENT SIDE OF THE
TUTT...WHICH WILL LIMIT STRONGEST ACTIVITY TO THE WINDWARD ISLANDS
AND NORTHEASTERN VENEZUELA...IN INTERACTION WITH THE ITCZ. THROUGH
FRIDAY MORNING EXPECTING AMOUNTS 15-20MM/DAY AND MAXIMA OF 25-50MM
FROM ST.LUCIA INTO NORTHEASTERN VENEZUELA. BY FRIDAY INTO EARLY
SATURDAY AND AFTER SCATTERED CONVECTION WILL PRODUCE ISOLATED
MAXIMA OF 15-25MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
42W     44W    46W    48W    51W    53W    56W    58W     TW
62W     65W    67W    70W    72W    74W    75W    77W     TW

TROPICAL WAVE ALONG 42W WILL APPROACH FRENCH GUIANA DURING
SATURDAY. STRONGEST CONVECTION WILL HOWEVER REMAIN OFFSHORE AS
TUTT IN THE LESSER ANTILLES WILL DRAW THE ITCZ NORTHWARD.

TROPICAL WAVE ALONG 62W IS INTERACTING WITH TUTT AND PRODUCING
MODERATE TO HEAVY RAINFALL ACROSS THE WINDWARD ISLANDS WITH
EXPECTED MAXIMA OF 25-50MM. CONVECTION WITH THIS WAVE WILL
DECREASE IN INTENSITY AS THE WAVE PROGRESSES INTO
VENEZUELA/SOUTHEASTERN CARIBBEAN...AS IT ENTERS THE CONVERGENT
SIDE OF TUTT MEANDERING OVER THE LESSER ANTILLES/SOUTHEASTERN
CARIBBEAN.

JN BAPTISTE...MS (SAINT LUCIA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
GALVEZ...WPC (USA)

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