337  
FXCA20 KWBC 261844  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
244 PM EDT FRI JUL 26 2024  
 
FORECAST BULLETIN 26 JUL 2024 AT 1845 UTC:  
CURRENTLY...LARGE AMOUNTS OF PRECIPITABLE WATER ARE OBSERVED  
ACROSS THE CARIBBEAN WATERS..SOUTHERN CENTRAL AMERICA.. AND  
NORTHERN SOUTH AMERICA. THERE IS A NARROW BAND OF MOISTURE  
TRAVERSING HISPANIOLA...ASSOCIATED WITH A TROPICAL WAVE PASSING  
THROUGH THE REGION. ADDITIONALLY...CENTRAL TO NORTHEASTERN MEXICO  
IS EXPERIENCING SLIGHTLY HIGHER-THAN-NORMAL MOISTURE CONTENT.  
HOWEVER...DRY AIR ASSOCIATED TO A RELATIVELY DENSE PLUME OF  
SAHARAN DUST IS EXPECTED TO START MOVING INTO THE CARIBBEAN  
REGION. THIS DUST PLUME IS EXPECTED TO TRAVERSE THE CARIBBEAN OVER  
THE COMING DAYS...NOTABLY IMPACTING THE GREATER ANTILLES AND THE  
BAHAMAS THIS SATURDAY AND SUNDAY. LOWER CONCENTRATIONS OF SAHARAN  
DUST MAY ALSO REACH THE YUCATAN PENINSULA AND PARTS OF NORTHERN  
CENTRAL AMERICA BY SUNDAY. THEREFORE...BY SUNDAY...MOST AREAS IN  
THE EASTERN TO CENTRAL CARIBBEAN ARE LIKELY TO EXPERIENCE A  
DECREASE IN THE MOISTURE LEVELS.  
 
IN TERMS OF UPPER-LEVEL DYNAMICS...THERE IS SUPPORT FOR CONVECTION  
OVER THE WESTERN GULF OF MEXICO AND PARTS OF CENTRAL MEXICO DUE TO  
AN UPPER TROUGH EXTENDING FROM CENTRAL UNITED STATES INTO NORTHERN  
MEXICO...INTERACTING WITH DEEP MOISTURE IN THE REGION.ELEVATED  
MOISTURE LEVELS OVER MEXICO...COMBINED WITH THE AFOREMENTIONED  
ELONGATED UPPER TROUGH OVER NORTHERN MEXICO... WILL SUSTAIN  
ONGOING RAINFALL ACTIVITY OVER CENTRAL AND NORTHEASTERN MEXICO IN  
THE FOLLOWING DAYS. EASTERLY LOW-LEVEL WIND FLOW INTO THE REGION  
FROM THE EASTERN PACIFIC WILL FACILITATE THE INLAND MOVEMENT OF  
MOISTURE CONVERGENCE...LEADING TO THE DEVELOPMENT OF PRECIPITATION  
ACTIVITY DUE TO OROGRAPHIC LIFT...PARTICULARLY ON FRIDAY AND  
SATURDAY. A MAXIMUM OF 30-70MM IS EXPECTED ON FRIDAY...ON SATURDAY  
AND SUNDAY TYPICAL SEASONAL PRECIPITATION OVER THE REGION IS  
FORECAST.  
 
ANOTHER UPPER-LEVEL LOW SITUATED ACROSS THE WESTERN TROPICAL  
ATLANTIC JUST EAST OF THE BAHAMAS IS OBSERVED AND IS EXPECTED TO  
CREATE ENOUGH INSTABILITY TO TRIGGER SQUALLY WEATHER ACROSS THE  
SOUTHERN BAHAMAS...TURKS AND CAICOS...AND A SLIGHT RISK OF SEVERE  
WEATHER IN CENTRAL CUBA. ALTHOUGH MOISTURE AVAILABILITY IS LIMITED  
IN THIS AREA...AN INCREASE IN MOISTURE OVER CUBA ON FRIDAY COULD  
LEAD TO HEAVIER PRECIPITATION...WITH ISOLATED MAXIMA OF 25-50MM  
EAST-CENTRAL CUBA. IN THE BAHAMAS...AND IN CENTRAL CUBA...EXPECT  
MAXIMA OF 15-25MM. FROM FRIDAY INTO SATURDAY...DRY CONDITIONS WILL  
PERSIST FOR THE REST OF THE FORECAST CYCLE.  
 
THE BASE OF THIS UPPER LEVEL TROUGH WILL BE IN PHASE WITH THE  
PASSAGE OF A TROPICAL WAVE OVER THE REGION...FAVORING THE  
CONVECTION OVER EASTERN CENTRAL AMERICA. AT THE SURFACE...A ROBUST  
HIGH-PRESSURE SYSTEM CONTINUES OVER THE ATLANTIC  
REGION...RESULTING IN EASTERLY TO SOUTHEASTERLY WINDS ACROSS THE  
ATLANTIC...CARIBBEAN...AND GULF OF MEXICO. THE TRADE  
WINDS...COMBINED WITH UPPER-LEVEL DIVERGENT FLOW AND ABUNDANT DEEP  
LAYER MOISTURE...IS FUELING A LINE OF THUNDERSTORMS STRETCHING  
FROM CENTRAL PANAMA TO SOUTHEAST NICARAGUA IN THE SOUTHWEST  
CARIBBEAN. THE PANAMANIAN LOW IS EXPECTED TO LINGER OVER THE  
SOUTHERN CARIBBEAN IN THE COMING DAYS. MOREOVER...IT IS CAUSING  
MOISTURE CONVERGENCE OVER COSTA RICA AND PANAMA. A TROPICAL WAVE  
IS EXPECTED OVER PANAMA ON SATURDAY...AND WILL LATER PROPAGATE  
TOWARDS HONDURAS AND NICARAGUA...WHERE THEY CAN EXPECT SIGNIFICANT  
RAINFALL ACROSS NICARAGUA AND NORTHERN HONDURAS ON SATURDAY AND  
SUNDAY. IN CENTRAL AMERICA...ÂCOSTA RICA AND PANAMA ARE EXPECTED  
TO RECEIVE THE MOST PRECIPITATION...AS THE PANAMANIAN TROUGH  
COMBINES WITH THE PASSAGE OF A TROPICAL WAVE. THIS WILL FAVOR A  
MAXIMA OF 40-80MM. AS THE SURFACE LOW AND THE TROPICAL WAVE MOVE  
CLOSER TO NICARAGUA...AND NORTHEAST HONDURAS FROM SATURDAY INTO  
SUNDAY...A MAXIMUM OF 40-80MM IS EXPECTED. THIS PRECIPITATION MAY  
BE SUBSTANTIAL.  
 
IN TROPICAL SOUTH AMERICA...FROM FRIDAY INTO SUNDAY...A PASSING  
TROPICAL WAVE AND A SURFACE TROUGH ARE LIKELY TO RESULT IN  
LOCALIZED HEAVY RAINFALL WITH A MAXIMUM OF 45MM FROM NORTH CENTRAL  
TO NORTHWESTERN COLOMBIA.ÂACROSS VENEZUELA...DESPITE UNFAVORABLE  
MID TO UPPER-LEVEL CONDITIONS FOR ENHANCED CONVECTIVE  
SUPPORT...THE MOISTURE ASSOCIATED WITH THE PASSAGE OF TROPICAL  
WAVE WILL FAVOR A MAXIMUM OF 40-80MM ON FRIDAY. BY SUNDAY...AN  
EASTERLY WAVE WILL BE MOVING OVER VENEZUELA FAVORING A MAXIMA OF  
50MM.  
 
LEDESMA...(WPC)  
ACOSTA...(WPC)  
FERNANDER...(BDM)  
CLARKE...(CINWS)  
 

 
 
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