SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
322 PM EDT THU JUL 25 2024

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SOUTH AMERICAN FORECAST BULLETIN FOR 25 JUL 2024 AT 1930 UTC:

ON THURSDAY...A POTENT UPPER LEVEL RIDGE IS LOCATED OVER
BRASIL...AND ANOTHER ONE IS LOCATED OVER THE EAST PACIFIC...WEST
OF PERU AND NORTH CHILE. THESE RIDGES ARE BLOCKING ANY NORTHWARD
MOVEMENT OF UPPER LEVEL TROUGHS FURTHER NORTH...AND THEY ARE
FAVORING DRIER CONDITIONS THROUGHOUT THE CONTINENT. TO THE
SOUTH....VARIOUS UPPER LEVEL TROUGHS ARE MAKING THEIR WAY OVER
CHILE AND ARGENTINA...WHERE THE UPPER LEVEL JETS ARE ASSISTING
WITH THE DIVERGENT CONDITIONS ALOFT. IN THE LOWER LEVELS...COLD
FRONTAL PASSAGES ARE EXPECTED TO ENTER THE SOUTHERN CONE OF SOUTH
AMERICA OVER THE NEXT SEVERAL DAYS. SOUTH-CENTRAL CHILE WILL BE
THE MAIN LOCATION WHICH WILL RECEIVE PRECIPITATION OVER THE NEXT
SEVERAL DAYS. HOWEVER...THE REGION WILL BE SEEING A POTENT HIGH
PRESSURE SYSTEM EXTEND FROM THE EASTERN PACIFIC INTO CENTRAL CHILE
AND ARGENTINA. BY SATURDAY...ANOTHER LOCATION THAT CAN EXPECT
PRECIPITATION IS SOUTHERN PARAGUAY...WITH THE DEVELOPMENT OF A
FRONTAL BOUNDARY THAT EXTENDS FROM SOUTHERN BOLIVIA...THROUGH
PARAGUAY...AND INTO SOUTHERN BRASIL. DUE TO THE LOW LEVEL OF
AVAILABLE MOISTURE THROUGHOUT THE REGION...PRECIPITATION AMOUNTS
ARE NOT EXPECTED TO BE HEAVY.

IN TERMS OF PRECIPITATION...ON THURSDAY...SOUTHERN CHILE CAN
EXPECT MAXIMA OF 20-45MM IN SOUTH AYSEN AND MAGALLANES...WHILE
SOUTH LOS LAGOS AND NORTH AYSEN...AS WELL AS..BIO BIO AND
ARAUCANIA CAN EXPECT MAXIMA OF 15 WITH CHANCE OF MOUNTAIN SNOW. ON
FRIDAY...A COLD MID TO UPPER LEVEL TROUGH WILL FAVOR INSTABILITY
OVER SOUTHERN CHILE...WHERE MAXIMA OF 20-40MM ARE EXPECTED WITH
THE CHANCE OF THUNDERSTORMS AND MOUNTAIN SNOW IN THE HIGHER
ELEVATIONS. ON SATURDAY...TOTAL PRECIPITATION BEGINS TO
DECREASE...AND MAXIMA EXPECTED ARE 20-35MM IN AYSEN AND NORTH
MAGALLANES. THE COLDER AIR IS EXPECTED TO FAVOR SNOWFALL IN THE
SOUTHERN AUSTRAL REGION OF CHILE...AND SNOWFALL MAXIMA OF 05-10CM
ARE EXPECTED.

TO THE NORTH...TROPICAL SOUTH AMERICA IS EXPECTED TO REMAIN DRY.
THE SOUTHERN PORTIONS OF TROUGHS AND TROPICAL WAVES ARE EXPECTED
TO FAVOR PRECIPITATION OVER SOUTHERN PORTIONS OF
VENEZUELA...COLOMBIA...AND THE GUIANAS. HOWEVER...MAXIMA ARE NOT
EXPECTED TO EXCEED 35MM. ON THURSDAY...MAXIMA OF 20-35MM ARE
EXPECTED IN THE GUIANAS. GENERALIZED MAXIMA OF 15-25MM ARE
EXPECTED IN WEST COLOMBIA...EAST COLOMBIA...INTO VENEZUELA. ON
FRIDAY...MAXIMA OF 25MM ARE EXPECTED IN SOUTHWEST COLOMBIA...AND
AMOUNTS OF 15-20MM ARE EXPECTED IN SOUTH VENEZUELA AND EAST
COLOMBIA...AS WELL AS IN SURINAME. BY SATURDAY...MOISTURE IS
EXPECTED TO ADVECT ALONG THE ANDES MOUNTAINS IN PERU. MAXIMA OF
15-20MM ARE EXPECTED IN AMAZONAS AND SAN MARTIN IN PERU...AS WELL
AS IN PORTIONS OF SOUTH CENTRAL PERU. SIMILAR AMOUNTS ARE EXPECTED
IN EAST COLOMBIA AND SOUTH VENEZUELA...AND AMAPA-BRASIL.

ACOSTA...(WPC)