349  
FXSA20 KWBC 091938  
PMDSA  
 
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
338 PM EDT MON SEP 09 2024  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/  
 
SOUTH AMERICAN FORECAST BULLETIN FOR 09 SEP 2024 AT 1945 UTC:  
 
ON MONDAY...A STRONG RIDGING PATTERN IS EXPECTED OVER THE NORTHERN  
PORTION OF THE REGION...WHILE A UPPER LEVEL TROUGH EXTENDS INTO  
PORTIONS OF SOUTHERN PORTIONS OF BOLIVIA. A WEAKER UPPER TROUGH  
EXTENDS TO THE WEST OF PERU AND IT IS EXPECTED TO PROCEED INLAND  
BY MONDAY EVENING. TO THE SOUTH...ANOTHER TROUGH IS EXPECTED TO  
EXTEND FROM THE CENTRAL PORTIONS TO CHILE...AND INTO SOUTHEASTERN  
ARGENTINA. THE ASSOCIATED UPPER JET ENTERS CENTRAL CHILE IN A  
ZONAL POSITION...AND COULD BRING FAVORABLE UPPER LEVEL CONDITIONS  
FOR PRECIPITATION IN CENTRAL CHILE INTO THE ZONA SUR...WITH THE  
ENTRANCE OF TWO FRONTAL BOUNDARIES INTO THE REGION BY MONDAY  
EVENING. MAXIMA OF 20-35MM ARE EXPECTED FROM CENTRAL CHILE TO LOS  
RIOS. TO THE EAST...ANOTHER FRONTAL BOUNDARY EXTENDS FROM NORTH  
ARGENTINA...THROUGH URUGUAY AND INTO THE SOUTH ATLANTIC OCEAN.  
WITH THE PRESENCE OF THE UPPER TROUGH...MAXIMA OF 15-30MM ARE  
EXPECTED IN EAST URUGUAY AND EXTREME SOUTHEAST RIO GRANDE DO SUL.  
 
ON TUESDAY...THE UPPER LEVEL TROUGH PROPAGATES TO THE  
NORTHEAST...EXTENDING INTO CENTRAL ARGENTINA AND BUENOS AIRES. AN  
INTENSIFICATION OF THE UPPER IS EXPECTED AS TWO JETS MAY BE  
EXPECTED TO COUPLE OVER EASTERN ARGENTINA BY TUESDAY EVENING. THE  
ENHANCE UPPER DIVERGENT CONDITIONS ARE EXPECTED TO EXTEND FROM  
EAST ARGENTINA INTO URUGUAY...AND IN ADDITION...THE PRESENCE OF  
SHORTWAVE TROUGHS IN THE MID LEVELS WILL FAVOR ELEVATED RISK OF  
SEVERE WEATHER INTO SOUTH URUGUAY. THE TRIGGER IS THE FRONTAL  
BOUNDARIES THAT ARE EXPECTED IN THE SAME REGION...WHERE THE COLD  
FRONT ADVANCING NORTH INTO CENTRAL AND EAST ARGENTINA WILL LIKELY  
PUSH AGAINST THE WEAKENING STATIONARY FRONT OVER CENTRAL URUGUAY  
AND NORTH ARGENTINA BY EARLY WEDNESDAY MORNING. MAXIMA OF 20-40MM  
ARE EXPECTED IN URUGUAY. EAST ARGENTINA CAN EXPECT MAXIMA OF  
15-25MM.  
 
ON WEDNESDAY...THE FRONTAL BOUNDARY CONTINUES TO PROPAGATE NORTH  
AND EXTENDS FROM CENTRAL BOLIVIA...TO NORTH RIO GRANDE DO SUL BY  
WEDNESDAY EVENING. THE POTENTIAL FOR SEVERE WEATHER HAS DECREASED  
WITH THE WEAKENING OF THE UPPER JETS OVER URUGUAY AND SOUTH  
BRASIL. FROM CORRIENTES-ARGENTINA TO RIO GRANDE DO SUL EXPECT A  
SLIGHT RISK OF SEVERE WEATHER WITH MAXIMA OF 20-35MM. MAXIMA OF  
15-25MM ARE EXPECTED IN URUGUAY AND ENTRE RIOS-ARGENTINA. IN  
SOUTHERN CHILE...EXPECT A SHORTWAVE TROUGH IN THE MID TO UPPER  
LEVELS TO FAVOR UPPER DIVERGENT CONDITIONS FOR PRECIPITATION IN  
THE ZONA AUSTRAL AND ZONA SUR OF CHILE. AN INCREASE IN  
PRECIPITABLE WATER DUE TO A WEAK INCOMING ATMOSPHERIC RIVER MAY  
FAVOR MAXIMA OF 20-35MM IN SOUTH AYSEN AND NORTH MAGALLANES...AND  
MAXIMA OF 15-25MM IN SOUTH MAGALLANES...WITH A CHANCE OF  
RAIN/SNOW.  
 
ACOSTA...(WPC)  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page