247  
FXCA20 KWBC 241910  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
310 PM EDT WED APR 24 2024  
 
FORECAST BULLETIN 24 APR 2024 AT 1900 UTC: AN EXTENSIVE SURFACE  
FRONT EXTENDS FROM THE NORTH ATLANTIC ACROSS THE SOUTHEAST  
BAHAMAS/CENTRAL CUBA AND IS BECOMING STATIONARY. BY WEDNESDAY  
EVENING EXPECT THE SYSTEM ACROSS THE SOUTHEAST BAHAMAS INTO  
CENTRAL CUBA...WHERE IT IS FORECAST TO REMAIN THROUGH FRIDAY  
MORNING. BY THEN...THE FRONT IS FORECAST TO START ADVANCING AS A  
COLD FRONT AGAIN...IN RESPONSE TO A POTENT UPPER TROUGH EXITING  
THE EAST COAST OF THE US. A SHEAR LINE IS ALSO ASSOCIATED WITH  
THIS SYSTEM...BUT IS FORECAST TO RAPIDLY WEAKEN AS IT MEANDERS  
FROM THE TURKS AND CAICOS/WINDWARD PASSAGE INTO REGIONS TO THE  
NORTHWEST...TO POTENTIALLY REFORM BY FRIDAY AS THE FRONT RESTARTS  
PROPAGATION. THE FRONT ITSELF WILL FAVOR LIMITED RAINFALL AMOUNTS.  
HOWEVER...LOCALLY HEAVY PRECIPITATION IS EXPECTED IN AREAS EAST OF  
THE SHEAR LINE...GIVEN THE PRESENCE OF A MOIST AIR MASS LOCATED IN  
PUERTO RICO AND HISPANIOLA. A PREFRONTAL TROUGH IS ORGANIZING  
INSIDE THIS AIR MASS...AND WILL PLAY A ROLE IN HIGHLIGHTING  
CONVECTION IN HISPANIOLA DURING THE NEXT THREE DAYS. THE MOST  
SIGNIFICANT PRECIPITATION THROUGH THE FORECAST CYCLE IS EXPECTED  
TO CLUSTER IN HISPANIOLA IN THE FORM OF AFTERNOON/EVENING  
THUNDERSTORMS...AS THE MOIST AND UNSTABLE AIR MASS INTERACT WITH  
UPPER TROUGH DYNAMICS. BY WEDNESDAY EXPECT 15-20MM/DAY AND  
ISOLATED MAXIMA OF 30-60MM. EXPECT A PEAK ON THURSDAY...WHEN  
AMOUNTS ARE FORECAST IN THE 25-50MM/DAY RANGE WITH POTENTIAL  
ISOLATED MAXIMA OF 75-125MM. ON FRIDAY...THE ARRIVAL OF ANOTHER  
MOIST PLUME FROM THE EAST WILL FAVOR MAXIMA OF40-80MM.  
 
THE FRONT/FRONTAL SHEAR LINE IN THE TROPICAL ATLANTIC IS FORECAST  
TO MOVE INTO THE LEEWARD ISLANDS LATER ON WEDNESDAY...TO THEN MOVE  
INTO THE WINDWARD ISLANDS WHILE LOSING DEFINITION DURING THURSDAY.  
REGARDLESS...LIMITED AMOUNTS OF AVAILABLE MOISTURE WILL LIMIT  
ACCUMULATION WITH THIS SYSTEM...LEADING TO VERY ISOLATED MAXIMA  
GENERALLY UNDER THE 15MM/DAY RANGE.  
 
ANOTHER REGION OF INTEREST IS PANAMA AND COSTA RICA. A TROUGH IS  
ORGANIZING IN/WESTERN COLOMBIA AND IS FORECAST TO GRADUALLY  
MEANDER WESTWARD ACCOMPANIED BY A MOIST PLUME. THIS WILL CONTONUE  
TO YIELD TO AN INCREASE IN THE COVERAGE AND INTENSITY OF  
PRECIPITATION IN SOUTHERN CENTRAL AMERICA. ON WEDNESDAY EXPECT  
15-20MM/DAY AND MAXIMA OF 35-70MM FROM NORTHWEST COLOMBIA/EJE  
CAFETERO INTO CENTRAL PANAMA. ON THURSDAY...EXPECT MAXIMA OF  
40-40MM MOSTLY IN CENTRAL PANAMA. ON FRIDAY...EXPECT THE FOCUS OF  
THE HEAVIEST PRECIPITATION IN COSTA RICA AND WEST PANAMA...WHERE  
EXPECT MAXIMA OF 20-45MM. ALSO IN THE REGION...FAVORABLE UPPER  
DIVERGENCE AND LOW-LEVEL ONSHORE FLOW IN NORTHERN ECUADOR/SOUTHERN  
COLOMBIA WILL FAVOR AN INCREASE IN THE AMOUNTS PRODUCED BY DIURNAL  
CONVECTION. EXPECT AN INCREASE ON THURSDAY...TO 15-20MM/DAY AND  
MAXIMA OF 40-80MM. ON FRIDAY EXPECT MAXIMA OF 30-60MM.  
 
AN EASTERLY WAVE IS PROPAGATING ACROSS EQUATORIAL PORTIONS OF  
SOUTH AMERICA. AS THIS WAVE ARRIVES INTO COLOMBIA...IT WILL FAVOR  
ONSHORE FLOW IN PORTIONS OF NORTHERN COLOMBIA. AS PRECIPITABLE  
WATER VALUES ARE EXPECTED TO REMAIN WELL ABOVE 60MM...EXPECT  
STRONG THUNDERSTORMS ON FRIDAY EVENING...WITH THE POTENTIAL OF  
PRODUCING MAXIMA OF 75-125MM AND WITH A RISK OF MCS FORMATION.  
 
GALVEZ/CLARKE/LEDESMA...WPC (USA)  
 

 
 
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