SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
411 PM EDT THU JUL 11 2024

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

EDIT MADE WAS TO DATE OF THE BULLETIN

SOUTH AMERICAN FORECAST BULLETIN FOR 11 JUL 2024 AT 2000 UTC:
IN THE CENTRAL PORTIONS OF THE CONTINENT ON THURSDAY...AN UPPER
LEVEL TROUGH IS POSITIVELY TILTED OVER CENTRAL CHILE AND
ARGENTINA...AND EXTENDS INTO SOUTHERN PERU AND CENTRAL BOLIVIA. TO
THE EAST OF THE TROUGH...THE COUPLING OF THE SUBTROPICAL JET AND
THE NORTH POLAR JET IS ASSISTING WITH UPPER DIVERGENCE OVER
PARAGUAY...AND RIO GRANDE DO SUL AND SANTA CATARINA IN BRASIL. THE
MOISTURE CONTENT OVER THE REGION IS EXPECT TO REMAIN LOW...WHERE
PRECIPITABLE WATER LEVELS ARE EXPECTED TO REMAIN BELOW 40MM. IN
THE MID LEVELS...THE TROUGH OVER THE REGION HAS THREE NOTABLE
SHORT WAVE TROUGHS THAT ARE EXPECTED TO PROPAGATE INTO SOUTHERN
PARAGUAY AND INTO SOUTH BRASIL...ALLOWING FOR FAVORABLE
CONVECTION. HOWEVER...DUE TO THE LOW MOISTURE CONTENT IN THE LOWER
LEVELS...AMOUNTS OF PRECIPITATION ARE NOT EXPECTED TO EXCEED 50MM
IN ALONG A TROUGH FROM EAST PARAGUAY...INTO SANTA CATARINA/RIO
GRANDE DO SUL. IN CENTRAL PERU AND BOLIVIA...THE MOISTURE ADVECTED
INTO THE REGION WILL FAVOR GENERALIZED MAXIMA OF 15 TO 35MM. ON
FRIDAY...THE MID TO UPPER LEVEL TROUGH IS EXPECTED TO
WEAKEN...WHILE THE SUBTROPICAL JET BECOMES ZONAL FROM NORTHERN
CHILE INTO SOUTHERN BRASIL. IN ADDITION...THE SUPPORT FROM THE
LOWER LEVELS IS EXPECTED TO DECREASE ACROSS THE REGION...AND
AMOUNTS OF PRECIPITATION IS ALSO EXPECTED TO DECREASE. THE REGION
WITH THE HEAVIEST PRECIPITATION IS EXPECTED OVER SANTA
CATARINA-BRASIL...WHERE EXPECT MAXIMA OF 20-35MM. ELSEWHERE IN THE
CENTRAL PORTION OF THE CONTINENT...MAXIMA ARE EXPECTED TO REMAIN
BELOW 20MM. BY SATURDAY...ANOTHER MID TO UPPER LEVEL TROUGH IS
EXPECTED FROM CHILE INTO URUGUAY. THE DIVERGENT SIDE OF THE
TROUGH...WILL FAVOR THE DYNAMICS FOR MAXIMA OF 25-50MM IN PARANA
AND SANTA CATARINA IN BRASIL...AS WELL AS EAST PARAGUAY. LOWER
AMOUNTS OF 20-35MM ARE EXPECTED IN SOUTHERN SANTA CATARINA INTO
RIO GRANDE DO SUL. THE DECREASE IN PRECIPITATION CONTINUES IN THE
MOUNTAIN REGIONS OF PERU...WHERE EXPECT MAXIMA BELOW 15MM.

IN THE SOUTHERN PORTION OF THE CONTINENT...A BLOCKING PATTERN
CONTINUES TO FAVOR DRIER CONDITIONS IN CHILE AND ARGENTINA. AS
SUCH...MUCH OF THE FRONTAL PASSAGES ARE REMAINING TO THE SOUTH OF
THE CONTINENT AND ARE EXPECTED TO MAKE IT INTO THE TIERRA DEL
FUEGO AND DRAKE PASSAGE REGION BY SATURDAY. HOWEVER...DUE TO THE
LOW MOISTURE CONTENT AND LACK OF FAVORABLE DYNAMICS IN THE UPPER
LEVELS...MAXIMA OF 15MM ARE EXPECTED ON FRIDAY AND SATURDAY.
OTHERWISE...EXPECT DRY CONDITIONS OVER THE NEXT THREE DAYS.

IN TROPICAL SOUTH AMERICA...THE PROPAGATION OF TROUGHS AND
TROPICAL WAVES ALONG THE ITCZ/NET IS EXPECTED TO FAVOR
PRECIPITATION IN THE REGION. EXPECT MAXIMA OF 20-40MM IN VENEZUELA
AND COLOMBIA ON THURSDAY. MAXIMA OF 30-60MM IS EXPECTED OVER SOUTH
COLOMBIA AND EAST ECUADOR. NORTH PERU CAN EXPECT MAXIMA OF
20-35MM. ON SATURDAY...VENEZUELA AND ECUADOR/NORTH PERU CAN EXPECT
MAXIMA OF 20-40MM.

ACOSTA..(WPC)