144  
FXCA20 KWBC 011856  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
256 PM EDT WED MAY 01 2024  
 
FORECAST BULLETIN 01 MAY 2024 AT 1900 UTC: THE MJO CONTINUES TO  
FAVOR CONVERGENCE IN THE UPPER LEVELS THROUGH THE FORECAST CYCLE.  
UNDER THIS PATTERN...EXPECT AREAS OF POTENTIALLY HEAVY  
PRECIPITATION TO REMAIN MOSTLY DISCRETE IN EXTENSION.  
 
A CELL OF THE SUBEQUATORIAL RIDGE CONTINUES TO LIMIT THE  
PROGRESSION OF MID TO UPPER LEVEL TROUGHS IN MEXICO. FURTHER  
EAST... THE PERSISTENCE OF THE RIDGE WILL SUPPORT THE  
AMPLIFICATION OF A MID-UPPER TROUGH OVER THE CARIBBEAN BASIN AND  
EXTENDS INTO CENTRAL COLOMBIA. A WEAK MID-UPPER SHORTWAVE TROUGH  
IS EMBEDDED WITHIN THE MAIN TROUGH AND MOVES OVER SE  
BAHAMAS...TURKS AND CAICOS...EASTERN CUBA...AND INTO HISPANIOLA.  
THERE REMAINS SOME DISAGREEMENT WITH THE EVOLUTION OF THE UPPER  
LEVEL TROUGH BETWEEN MODELS FROM THURSDAY THROUGH FRIDAY. AS A  
RESULT THE EXACT LOCATION OF THE BASE OF THE UPPER LEVEL TROUGH  
AND THE AXIS IS UNCERTAIN. A FRONTAL BOUNDARY IS LOCATED OVER THE  
CENTRAL ATLANTIC AND EXTENDS JUST OF PUERTO  
RICO...HISPANIOLA...AND INTO TURKS AND CAICOS ON WEDNESDAY. THE  
APPROACHING UPPER LEVEL TROUGH IS EXPECTED TO ENHANCE THE  
DEVELOPMENT OF UNDULATION OF THE EXISTING FRONTAL  
BOUNDARY...HOWEVER IT IS NOT SUSTAINED THROUGHOUT THE CYCLE.  
HEAVIEST PRECIPITATION IS EXPECTED FROM WEDNESDAY INTO  
THURSDAY...AND DECREASES BY FRIDAY.  
 
ON WEDNESDAY...ENHANCED CONVECTIVE ACTIVITY OVER SOUTH  
BAHAMAS...TURKS AND CAICOS...AND NORTHERN HISPANIOLA...WILL FAVOR  
MAXIMA OF 30-60MM WITH MODERATE RISK OF SQUALLY/SEVERE WEATHER.  
WHILE NORTHEAST CUBA AND JAMAICA CAN EXPECT A MAXIMA OF 20-35MM.  
THE EASTERN PORTION OF CUBA CAN EXPECT SLIGHT RISK OF SEVERE  
WEATHER. CENTRAL BAHAMAS...CENTRAL CUBA...PUERTO RICO...SOUTHERN  
HISPANIOLA...AND HAITI CAN EXPECT GENERAL MAXIMA OF 15-25MM. ON  
THURSDAY...THE UPPER LEVEL TROUGH PROPAGATES TO THE EAST...AND ITS  
CONVERGENT SIDE IS LOCATED OVER THE NORTHERN CARIBBEAN...AS SUCH A  
DECREASE IN PRECIPITATION TOTALS IS FORECAST. IN NORTHERN  
DOMINICAN REPUBLIC...EASTERN CUBA...AND JAMAICA...CAN EXPECT  
GENERAL MAXIMA OF 20-45MM. PUERTO RICO CAN EXPECT MAXIMA OF  
20-35MM WITH A MARGINAL RISK OF SEVERE WEATHER. ELSEWHERE IN  
CENTRAL CUBA...AND THE NORTHERN LESSER ANTILLES...EXPECT  
GENERALIZED MAXIMA OF 15-25MM. ON FRIDAY...A DECREASE IN  
PRECIPITATION THE CARIBBEAN IS EXPECTED..AS THE UPPER TROUGH  
CONTINUES PROPAGATING EAST. THE DOMINICAN REPUBLIC...PUERTO  
RICO...AND THE NORTHERN LESSER ANTILLES CAN EXPECT MAXIMUM OF  
20-45MM. MAXIMA OF 10-20MM ARE FORECAST FOR HAITI...JAMAICA...AND  
LESSER ANTILLES.  
 
ELSEWHERE IN CENTRAL AMERICA...AND MEXICO...SEASONAL PRECIPITATION  
IS EXPECTED THROUGH THE FORECAST CYCLE. THIS WILL BE INHIBITED BY  
THE CONVERGENT MJO PATTERN THAT PERSISTS IN THE UPPER LEVELS.  
EXPECT ISOLATED MAXIMA TO REMAIN BELOW THE 20-25MM RANGE IN  
PORTIONS OF EASTERN MEXICO...SOUTHERN GUATEMALA...THE GOLF OF  
FONSECA REGION...COSTA RICA...AND PANAMA.  
 
IN NORTHERN SOUTH AMERICA...EASTERLY WAVES ARE EXPECTED TO  
INTERACT WITH THE ITCZ/NET AS THEY PROPAGATE TO THE WEST...DIURNAL  
CONVECTION IS EXPECTED TO FAVOR MAXIMA OF 20-35MM IN  
AMAPA-BRASIL...AND INTO PARA. SIMILAR AMOUNTS ARE EXPECTED IN  
CENTRAL COLOMBIA...NORTHEAST PERU...AND WESTERN ECUADOR. MAXIMA OF  
30-60MM ARE EXPECTED IN THE LAKE MARACAIBO REGION AND INTO NORTH  
COLOMBIA. IN WESTERN COLOMBIA AND WESTERN ECUADOR...FAVORABLE  
ONSHORE FLOW WILL FAVOR MAXIMA OF 30-60MM IN WESTERN  
COLOMBIA...AND 20-35MM IN NORTHWEST ECUADOR. ON THURSDAY...A  
DECREASE IN VALUES IS EXPECTED...AS CONDITIONS LESS CONDUCIVE FOR  
SUSTAIN DEEP CONVECTION. EXPECT GENERALIZED MAXIMA OF 20-45MM FROM  
THE LAKE MARACAIBO REGION...ALONG WEST COLOMBIA...AND INTO WEST  
ECUADOR. THE EASTERLY WAVES WILL FAVOR MAXIMA OF ISOLATED 20-35MM  
FROM EASTERN COLOMBIA...INTO VENEZUELA...GUYANA...AND NORTHERN  
BRASIL. ON FRIDAY...THE POSSIBLE ENHANCEMENT OF DEEP CONVECTION  
OVER NORTHERN COLOMBIA IS LIKELY UNDER THE INFLUENCE OF THE BASE  
OF THE UPPER LEVEL TROUGH. IN WESTERN COLOMBIA...ONSHORE FLOW  
FAVORS DEEP CONVECTION IN THE REGION. COLOMBIA CAN EXPECT MAXIMA  
OF 30-60MM. TO THE EAST...EASTERLY WAVE PROPAGATION WILL FAVOR  
ISOLATED CONVECTION...AND MAXIMA OF 20-35MM IN SOUTHEAST  
COLOMBIA...INTO SOUTHERN VENEZUELA...AND RORAIMA-BRASIL.  
 
CLARKE/LEDESMA/ACOSTA...WPC (USA)  
 

 
 
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