754  
FXCA20 KWBC 061656  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1156 AM EST WED DEC 06 2023  
 
FORECAST BULLETIN 06 DEC 2023 AT 1650 UTC: THE BUILDING OF A POLAR  
RIDGE IN THE SOUTHERN USA IS FAVORING THE STRENGTHENING OF  
NORTHERLY LOW-LEVEL WINDS ACROSS THE GULF OF MEXICO. THIS IS  
AIDING WITH THE SOUTHWARD PROGRESSION OF A SURFACE FRONT. ON  
WEDNESDAY EVENING THE FRONT IS EXPECTED ACROSS THE CENTRAL  
BAHAMAS...CENTRAL CUBA...CAYMAN ISLANDS...ISLAS DE LA  
BAHIA...CENTRAL GUATEMALA INTO THE CONTINENTAL DIVE TO THE CHIVELA  
PASS AND CENTRAL MEXICO. ON THURSDAY EXPECT THE FRONT ACROSS  
NORTHERN HISPANIOLA...JUST NORTH OF JAMAICA...ISLAS DE LA  
BAHIA...NORTHWEST HONDURAS...CENTRAL GUATEMALA. BY FRIDAY EVENING  
EXPECT IT ACROSS INAGUA AND THE TURKS AND CAICOS...SOUTHEAST  
CUBA...ISLA DE LA JUVENTUD...YUCATAN CHANNEL. A SHEAR LINE IS ALSO  
ORGANIZING. ON WEDNESDAY EXPECT AN ILL-DEFINED BOUNDARY ACROSS  
CENTRAL HISPANIOLA...15N 80W. ON THURSDAY EXPECTING ALONG THE MONA  
PASSAGE...BARAHINA...INTO NORTHEAST NICARAGUA. ON FRIDAY EVENING  
EXPECT IT ALONG CENTRAL HISPANIOLA...JAMAICA INTO NORTHERN BELIZE.  
 
INITIALLY...ENHANCED MOISTURE CONVERGENCE IN SOUTHERN  
VERACRUZ/NORTHERN OAXACA...ASSOCIATED WITH A NORTES EVENT...WILL  
TRIGGER 20-40MM/DAY AND MAXIMA OF 75-125MM. FRONTAL CONVECTION IN  
ISLAS DE LA BAHIA/NORTHWEST HONDURAS/EASTERN GUATEMALA WILL FAVOR  
MAXIMA OF 35-70MM. SCATTERED PRECIPITATION IS EXPECTED ALSO IN  
BELIZE/NORTHERN GUATEMALA/TABASCO/CHIAPAS WHERE EXPECT MAXIMA OF  
20-35MM...AS NORTHEASTERLY LOW-LEVEL WINDS INTERACT WITH TERRAIN.  
IN THE GREATER ANTILLES AND BAHAMAS EXPECT VERY LIGHT ACCUMULATION  
DUE TO LIMITED AMOUNTS OF AVAILABLE MOISTURE AND THE INFLUENCE OF  
THE MID-LEVEL RIDGE LINGERING IN THE GREATER ANTILLES. ON  
THURSDAY...EXPECT 15-20MM/DAY AND MAXIMA OF 30-60MM IN CENTRAL  
GUATEMALA AND SOUTHERN BELIZE. IN NORTH-CENTRAL HONDURAS AND ISLAS  
DE LA BAHIA...EXPECT MAXIMA OF 20-35MM IN FRONTAL CONVECTION. THE  
SHEAR LINE WILL FAVOR SIMILAR AMOUNTS IN NORTHEAST  
NICARAGUA/EASTERN HONDURAS. IN THE GREATER ANTILLES...EXPECT  
MAXIMA OF 20-35MM IN MOST OF NORTHERN AND EASTERN HISPANIOLA AND  
IN NORTHEAST HAMAICA. SHEAR LINE CONVECTION WILL FAVOR MAXIMA OF  
15MM IN PUERTO RICO. ON FRIDAY...EXPECT MAXIMA OF 20-40MM IN THE  
DOMININCAN REPUBLIC...WHILE IN NORTHERN HAITI AND IN SOUTHEAST  
CUBA...ENHANCED MOISTURE CONVERGENCE WILL FAVOR MAXIMA OF 15-25MM.  
SIMILAR AMOUNTS ARE EXPECTED IN JAMAICA AND IN BELIZE/QUINTANA ROO.  
 
AN UPPER TROUGH OVER THE TROPICAL ATLANTIC...EAST OF THE LESSER  
ANTILLES...HAS INDUCED A FEW PERTURBATIONS IN THE EASTERLY TRADES  
AND HAS MODULATED THE ITCZ NORTHWARD. GIVEN THE PERSISTENCE OF THE  
UPPER TROUGH THROUGH FRIDAY...EXPECT INTERACTION BETWEEN THE UPPER  
TROUGH...INDUCED PERTURBATION...AND THE MOIST PLUME ENTERING THE  
CARIBBEAN...TO FAVOR MODERATE PRECIPITATION PRIMARILY IN THE  
WINDWARD ISLANDS. ON WEDNESDAY EXPECT 10-15MM/DAY AND MAXIMA OF  
20-40MM. IN TRINIDAD AND TOBAGO AND NORTHEAST VENEZUELA. ON  
THUSDAY EXPECT SIMILAR AMOUNTS DEVELOPING FROM NORTHEAST VENEZUELA  
THROUGH THE CENTRAL LESSER ANTILLES. ON FRIDAY...EXPECT MAXIMA OF  
30-60MM IN THE WINDWARD ISLANDS...AND MAXIMA OF 20-45MM IN THE  
FRENCH ANTILLES.  
 
IN NORTHERN SOUTH AMERICA...THE MOST ACTIVE IS EXPECTED IN THE  
AMAZON BASIN TO THE SOUTH OF 04N AND WEST OF 60W...WHERE SCATTERED  
MOISTURE CONVERGENCE AND PRECIBITABLE VALUES EXCEED 50MM. WESTERN  
COLOMBIA AND NORTHWEST ECUADOR WILL ALSO REMAIN SEASONALLY ACTIVE  
AS MOIST ONSHORE FLOW FAVORS SCATTERED CONVECTION ON A DAILY  
BASIS. A DECREASE IN THE LOW-LEVEL WESTERLIES WILL FAVOR A GRADUAL  
DECREASE IN ACCUMULATION THROUGH THE CYCLE. ON WEDNESDAY EXPECT  
MAXIMA OF 30-60MM FROM CENTRAL ECUADOR INTO NORTHWEST COLOMBIA.  
THIS DECREASES TO MAXIMA OF 15-25MM FROM CENTRAL ECUADOR INTO THE  
EJE CAFETERO BY FRIDAY.  
 
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC  
NONE  
 
GALVEZ...WPC (USA)  
 
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