972  
FXSA20 KWBC 262336  
PMDSA  
 
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
735 PM EDT MON AUG 26 2024  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/  
 
SOUTH AMERICAN FORECAST BULLETIN FOR 26 AUG 2024 AT 2325 UTC:  
 
MOST OF THE SOUTH AMERICAN CONTINENT IS EXPECTED TO REMAIN  
RAIN-FREE OVER THE NEXT FEW DAYS. THE EXCEPTIONS WOULD BE PORTIONS  
OF SOUTHERN CHILE...A FEW SECTIONS OF SOUTHEASTERN ARGENTINA...AND  
MANY SECTORS OF VENEZUELA...COLOMBIA AND PERU. OUT OF THESE  
SECTORS...SOUTHERN CHILE HAS A CHANCE OF A MIX OF RAIN AND  
SNOW...WHILE NORTHWESTERN SOUTH AMERICA WILL HAVE SHOWERS AND  
THUNDERSTORMS EACH DAY INTO MIDWEEK. EVEN THOUGH OUR SURFACE  
CHARTS DO SHOW SOME SURFACE TROUGHS OVER THE SOUTH AMERICAN  
CONTINENT...AS WELL AS A FEW FRONTAL BOUNDARIES AND SHEAR LINES  
OVER SMALL SECTIONS...MOST OF THE FRONTAL BOUNDARIES AND STRONG  
WINDS IN THE CHARTS ARE LOCATED OVER THE WATERS.  
 
TONIGHT INTO EARLY TUESDAY...PORTIONS OF NORTHERN PERU...EASTERN  
ECUADOR AND SOUTHERN COLOMBIA ARE FORECAST TO OBSERVE NEAR 10-20MM  
WITH MAX VALUES UP TO 60MM. THIS IS DUE TO THE REMNANTS OF AN OLD  
FRONTAL BOUNDARY THAT KEEPS MOVING NORTH AS IT WEAKENS.  
HOWEVER...IT WILL STILL BRING AN INCREASE OF LOCALIZED MOISTURE TO  
THE AREA...CAUSING SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE  
AREA. THERE IS ALSO A SHEAR LINE THAT EXTENDS FROM EAST CENTRAL  
BRAZIL TO NORTHWESTERN BRAZIL. THIS SHEAR LINE IS CAUSING SOME  
CONVECTION ALONG IT...PARTICULARLY OVER NORTHWESTERN BRAZIL INTO  
SOUTHERN VENEZUELA. ELSEWHERE IN SOUTH AMERICA...THE TAIL END OF A  
COLD FRONT AND A PRE-FRONTAL TROUGH ARE SKIRTING THE EAST CENTRAL  
COAST OF BRAZIL. THIS WILL BRING SOME MOISTURE TO THE AREA AND  
THEREFORE HELP THE DEVELOPMENT OF SOME SHOWER ACTIVITY ALONG THE  
EAST CENTRAL COAST OF BRAZIL FROM THE COAST OF RIO DE  
JANEIRO...NORTH INTO SOUTHERN BAHIA. THE OTHER NOTEWORTHY  
PRECIPITATION WOULD BE IN CHILE OVER PORTIONS OF SOUTHERN AYSEN  
AND NORTHERN MAGALLANES...WHERE A RAIN AND SNOW MIX COULD  
ACCUMULATE TO AS MUCH AS 20MM TODAY. MEANWHILE ACROSS AREAS IN AND  
AROUND RIO NEGRO AND CHUBUT IN ARGENTINA WOULD OBSERVE SOME RAIN  
AND RAIN AND SNOW MIX BUT ACCUMULATIONS WILL BE MINIMAL.  
 
FOR TUESDAY INTO EARLY WEDNESDAY...THE AMOUNT OF RAIN IN THE  
FORECAST INCREASES FOR THE REGION OF BAHIA IN EASTERN  
BRAZIL...WITH THE FORECAST SUGGESTING MAX TOTALS OF UP TO 20 MM ON  
THE SOUTHERN PORTION OF THE REGION BUT STILL UP TO 10 MM ON THE  
NORTHERN PORTION OF THAT EASTERN COAST OF BAHIA. ACROSS THE REST  
OF THE SOUTH AMERICAN CONTINENT...THE AMOUNT OF FORECAST RAINFALL  
REMAINS FAIRLY MODEST. FOR NORTHERN SOUTH AMERICA...THERE IS A  
TROPICAL WAVE THAT IS REACHING THE GUIANAS AND ALSO A TROUGH OVER  
VENEZUELA. HOWEVER...THE FORECAST RAINFALL AMOUNTS FOR THE GUIANAS  
WILL BE GENERALLY BETWEEN 5 AND 10 MM WITH MAX AMOUNTS OF  
25MM...WHILE PORTIONS OF VENEZUELA AND PERHAPS EASTERN COLOMBIA  
COULD OBSERVE UP TO 35 MM. THERE IS A COLD FRONT APPROACHING THE  
SOUTHERN REGION OF CHILE PARTICULARLY FROM AYSEN TO  
MAGALLANES...WHERE THERE IS A CHANCE OF A MIX OF RAIN AND SNOW AND  
THE AMOUNTS OF PRECIPITATION COULD BE BETWEEN 10 AND 15 MM WITH  
MAX VALUES UP TO 35 MM. THIS IS DUE TO DIRECT ONSHORE FLOW COMING  
IN WITH SOME MOISTURE INTERACTING WITH THE TERRAIN. A VERY SMALL  
PORTION OF SOUTHERN BRAZIL...NEAR SANTA CATARINA...COULD OBSERVE  
LIGHT RAIN...AS WELL AS SOME PORTIONS OF PERU AND BOLIVIA...BUT  
THE AMOUNT OF RAIN IS EXPECTED TO BE MINIMAL WITH NO SIGNIFICANT  
ACCUMULATION.  
 
LITTLE CHANGE IS EXPECTED ACROSS THE CONTINENT FROM WEDNESDAY INTO  
THURSDAY. THERE IS HOWEVER AN INCREASE OF RAINFALL EXPECTED OVER  
BAHIA IN EASTERN BRAZIL...WHERE MAX AMOUNTS OF RAIN BETWEEN 20 AND  
40 MM ARE FORECAST...AS A WEAKENING COLD FRONT MOVES ACROSS THE  
ATLANTIC AND AFFECTS THE EASTERN SHORE OF THE REGION...AND ONSHORE  
WIND FLOW PUSHES MOISTURE TO THE AREA. ACROSS NORTHERN SOUTH  
AMERICA...THE TROPICAL WAVE IS EXPECTED TO BE APPROACHING EASTERN  
VENEZUELA....AND A SURFACE TROUGH WOULD BE OVER WESTERN VENEZUELA  
INTO EASTERN COLOMBIA. THE EXPECTED RAINFALL OVER NORTHERN SOUTH  
AMERICA IS THAT OF 05-10MM WITH MAX VALUES UP TO 30MM OVER THE  
GUIANAS...WHILE VENEZUELA AND COLOMBIA WOULD HAVE AMOUNTS UP TO  
20MM. SOUTHERN CHILE WOULD REMAIN OBSERVING THE DIRECT COLD  
ONSHORE FLOW FROM THE SOUTHERN PACIFIC AS A SURFACE HIGH PRESSURE  
IS EXPECTED TO BE LOCATED JUST WEST OF SOUTH CENTRAL CHILE. THIS  
SETUP WILL ONCE AGAIN CAUSE SOME RAIN AND SNOW MIX OVER THE  
SOUTHERN PORTIONS OF CHILE...THIS TIME WITH PRECIPITATION  
ACCUMULATIONS NEAR 05-10MM WITH MAX VALUES UP TO 15MM.  
 
ALAMO...(WPC)  
LOPEZ...(DMH PARAGUAY)  
PALAVECINO (SMN ARGENTINA)  
 

 
 
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