977  
FXCA20 KWBC 141857  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
257 PM EDT FRI JUN 14 2024  
 
FORECAST BULLETIN 14 JUN 2024 AT 1845 UTC:  
 
THE MAIN STORY OF THE DAY CONTINUES TO BE THE DEVELOPING CENTRAL  
AMERICAN GYRE...WHICH WILL CAUSE SIGNIFICANT RAINFALL ACROSS  
CENTRAL AMERICA INTO SOUTHERN MEXICO OVER THE NEXT SEVERAL DAYS.  
THE MODEL GUIDANCE HAS A 72-HOUR TOTAL ACCUMULATED RAINFALL TOTALS  
THAT RANGE BETWEEN 250 AND 400MM FROM TODAY INTO MONDAY FOR THE  
PACIFIC COAST OF WESTERN PANAMA TO EL SALVADOR. WITH COSTA RICA  
RECEIVING THE HIGHEST AMOUNTS...BUT THERE IS SOME UNCERTAINTY ON  
THE EXACT LOCATION OF THE ISOLATED HIGHEST AMOUNTS...SO IT IS  
WORTH KNOWING THAT THERE WILL BE PERSISTENT FLOW INTO THE PACIFIC  
COAST OF CENTRAL AMERICA FROM THE MONSOON TROUGH...WHICH IS  
CARRYING HIGHER MOISTURE THAN NORMAL AND WILL THEN CAUSE THE  
SIGNIFICANT RAINFALL EXPECTED THIS WEEKEND AND BEYOND. THIS EVENT  
WILL BE PROLONGED INTO NEXT WEEK AND COULD CAUSE VERY HAZARDOUS  
CONDITIONS FOR PORTIONS OF CENTRAL AMERICA. THE HIGHEST AMOUNTS OF  
RAIN THIS WEEKEND...AS MENTIONED ABOVE...IS EXPECTED TO BE IN AND  
AROUND COSTA RICA...BUT BY THE MIDDLE TO THE LATTER PARTS OF NEXT  
WEEK...THE HIGHEST AMOUNTS WOULD BE OVER THE PACIFIC COAST OF  
SOUTHWESTERN NICARAGUA...PORTIONS OF HONDURAS...EL  
SALVADOR...GUATEMALA AND INTO CHIAPAS OF MEXICO. THE MODEL  
GUIDANCE IS SUGGESTING UPWARDS OF 500 - 700MM OF RAIN FOR THE  
ENTIRE EVENT BEFORE IT MAY START TO SETTLE DOWN BY THE END OF NEXT  
WEEK.  
 
FOR TODAY INTO SATURDAY MORNING...WESTERN PANAMA INTO COSTA RICA  
ARE FORECAST TO OBSERVE RAINFALL MAXIMA UP TO 150MM...WHILE OTHER  
AREAS OF CENTRAL AMERICA HAVE FORECAST MAXIMA RANGING FROM AROUND  
30MM TO 60MM. NORTHERN SOUTH AMERICA WILL HAVE A FEW TROPICAL  
WAVES AND TROUGHS MOVING THROUGH...CAUSING INTERMITTENT PERIODS OF  
SHOWERS AND THUNDERSTORMS ACROSS THE AREA. THE RAINFALL MAXIMA  
WILL BE HIGHEST ACROSS THE GUIANAS INTO EASTERN VENEZUELA...AS  
WELL AS WESTERN COLOMBIA WITH TOTALS NEAR 60 AND 100MM...WHILE  
OTHER AREAS WILL OBSERVE MAXIMA OF 25 TO 45MM. THE CARIBBEAN  
REGION WILL BE RELATIVELY QUIET AS DRIER AIR WITH SAHARAN DUST  
WILL START MOVING IN...BUT THE EXCEPTION WILL BE WESTERN CUBA AND  
THE EASTERN SHORE OF THE YUCATAN PENINSULA...WHERE MAX VALUES UP  
TO 60MM COULD BE OBSERVED.  
 
FOR SATURDAY INTO SUNDAY...THE HEAVY RAINFALL EXPECTED OVER  
CENTRAL AMERICA WILL START TO EXPAND TO THE NORTH. COSTA RICA AND  
PANAMA ARE STILL EXPECTED TO RECEIVE THE HIGHEST RAINFALL MAXIMA  
OF THE AREA...WITH TOTALS NEAR 75-150MM. HOWEVER...THE REST OF  
CENTRAL AMERICA...ESPECIALLY THE PACIFIC SIDE INTO PORTIONS OF  
CHIAPAS...COULD OBSERVE RAINFALL MAXIMA BETWEEN 40-80MM. NORTHERN  
SOUTH AMERICA WILL CONTINUE HAVING THE TROPICAL WAVES AND  
TROUGHS...CAUSING DAILY RAINFALL MAXIMA BETWEEN 40 AND 80MM IN  
SOME AREAS. THE CARIBBEAN CONTINUES TO BE RELATIVELY  
QUIET...THOUGH THE YUCATAN PENINSULA CONTINUES TO HAVE AREAS WITH  
SIGNIFICANT RAINFALL...POSSIBLY REACHING TOTALS NEAR 40-80MM.  
 
SUNDAY INTO MONDAY WOULD BE THE DAY WHERE THE VERY HEAVY RAIN  
STARTS TO MOVE TO EL SALVADOR AND GUATEMALA IN CENTRAL AMERICA.  
ALTHOUGH PORTIONS OF COSTA RICA ARE STILL FORECAST TO OBSERVE  
MAXIMA UP TO 100MM...PORTIONS OF NICARAGUA INTO GUATEMALA AND EL  
SALVADOR COULD OBSERVE RAINFALL MAXIMA BETWEEN 100 AND 200MM IN A  
24-HOUR PERIOD...WHICH IS VERY SIGNIFICANT FOR THAT AREA. OTHER  
AREAS IN CENTRAL TO NORTHERN GUATEMALA...AS WELL AS THE YUCATAN  
PENINSULA AND CHIAPAS COULD OBSERVE SHOWERS AND  
THUNDERSTORMS...WITH RAINFALL TOTALS REACHING NEAR 50MM. NORTHERN  
SOUTH AMERICA START TO OBSERVE LESS RAINFALL FOR THAT  
PERIOD...WITH ONLY A FEW AREAS OF WESTERN VENEZUELA AND  
SOUTHWESTERN COLOMBIA AND ECUADOR HAVING UP TO 50MM OF RAINFALL  
FORECAST...WHILE THE REST OF THE AREA IS FORECAST RAINFALL MAXIMA  
OF AROUND 35MM OR LESS. ONCE AGAIN...THE CARIBBEAN IS EXPECTED TO  
REMAIN RELATIVELY QUIET EVEN THOUGH THERE MAY BE A SFC TROUGH NEAR  
HISPANIOLA...THE DRY AIR AND SAHARAN DUST WILL LIKELY LIMIT THE  
SHOWER ACTIVITY ACROSS THE AREA...AND THUS A MAX RAINFALL OF 10MM  
ARE FORECAST ACROSS THE ANTILLES.  
 
CURRENTLY THERE IS A STRONG SFC HIGH PRESSURE ACROSS THE CENTRAL  
ATLANTIC CAUSING EASTERLY WINDS ACROSS THE ATLANTIC INTO THE  
CARIBBEAN. THERE IS ALSO A SFC TROUGH ACROSS THE WESTERN TROPICAL  
ATLANTIC AND ANOTHER ACROSS THE GULF OF MEXICO. SEVERAL TROPICAL  
WAVES WILL BE MOVING THROUGH THE REGION AS WELL...THOUGH MOSTLY  
SOUTH OF 13N...AND MOST OF THEM WOULD DISSIPATE BY THE TIME THEY  
REACH CENTRAL AMERICA AS THEY WOULD BE ABSORBED BY THE SFC TROUGH  
AND EVENTUAL CENTRAL AMERICAN GYRE.  
 
IN SUMMARY...THE LATEST GUIDANCE CONTINUES TO SUGGEST THAT THE SFC  
TROUGH ACROSS THE GULF OF MEXICO...AND THE POSITIONING OF THE  
MONSOON TROUGH IN THE PACIFIC WILL CAUSE A VERY MOIST ONSHORE FLOW  
INTO CENTRAL AMERICA FOR THE NEXT SEVERAL DAYS AS A CENTRAL  
AMERICAN GYRE DEVELOPS. THE ABOVE NORMAL MOISTURE THAT WILL BE  
PRESENT IN THE ONSHORE FLOW TOWARDS CENTRAL AMERICA WILL COMBINE  
WITH THE UP-SLOPE EFFECT OF CERTAIN PORTIONS OF CENTRAL  
AMERICA...CAUSING PERSISTENT RAINFALL DEVELOPMENT.  
 
WE WILL CONTINUE TO MONITOR THE SITUATION IN CENTRAL AMERICA  
CLOSELY.  
 
ALAMO (WPC)  
CLARKE (CINWS)  
FERNANDER (BDM)  
 

 
 
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