SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
207 PM EST FRI FEB 07 2025

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

SOUTH AMERICAN FORECAST BULLETIN FOR 07 FEB 2025 AT 1900 UTC:

SHOWERS AND THUNDERSTORMS WILL BE OBSERVED OVER TROPICAL SOUTH
AMERICA OVER THE NEXT THREE DAYS. ALTHOUGH PORTIONS OF EASTERN
BRASIL WILL BE RELATIVELY DRY...DAILY THUNDERSTORMS ARE EXPECTED
ELSEWHERE IN BRASIL. PERU AND ECUADOR WILL HAVE A BETTER CHANCE OF
THUNDERSTORMS ON SATURDAY AND SUNDAY AS MOISTURE MOVES IN. THERE
WILL BE TWO ATMOSPHERIC RIVERS MOVING INTO SOUTHERN CHILE...ONE
TODAY AND ANOTHER ONE ON SUNDAY...WHICH WILL CAUSE AN INCREASE IN
MOISTURE AND SHOWER ACTIVITY OVER THE AREA...INCLUDING SOUTHERN
ARGENTINA. THE PROXIMITY OF THE ITCZ WILL CAUSE PERSISTENT
RAINFALL OVER PORTIONS OF NORTHERN BRASIL...NEAR AMAPA AND
NORTHERN PARA.

IN THE UPPER LEVELS...A STRONG LOW PRESSURE WILL CONTINUE TO MOVE
SOUTHWEST ACROSS EASTERN BRASIL. A SHORTWAVE TROUGH HAS ITS BASE
OVER WESTERN PERU AND A HIGH PRESSURE IS PRESENT OVER NORTHERN
CHILE INTO NORTHERN ARGENTINA. THIS HIGH PRESSURE WILL STRENGTHEN
AND MOVE NORTHWESTWARD INTO THE COAST OF SOUTHERN PERU AND
NORTHERN CHILE BY SUNDAY. STRONG WINDS IN THE UPPER LEVELS WILL
PERSIST OVER AUSTRAL SOUTH AMERICA. A DIFFLUENT PATTERN WILL
PERSIST OVER TROPICAL SOUTH AMERICA...WHICH WILL HELP WITH THE
THUNDERSTORM DEVELOPMENT EXPECTED OVER THE NEXT FEW DAYS.

IN THE MID LEVELS...THERE ARE ALSO RELATIVELY STRONG WINDS ACROSS
AUSTRAL SOUTH AMERICA...WHICH WILL PERSIST THROUGH THE
WEEKEND...THOUGH A SHORTWAVE TROUGH WILL MOVE THROUGH TONIGHT INTO
SATURDAY...THEN ANOTHER MID LEVEL TROUGH WILL MOVE IN ON SUNDAY
NIGHT IN MONDAY. THESE MID LEVEL TROUGHS WILL COINCIDE WITH THE
ATMOSPHERIC RIVERS...WHICH WILL HELP IN PROVIDING INSTABILITY AND
INCREASING THE CHANCES OF SHOWERS OVER THE AREA.

FROM TODAY INTO THE WEEKEND...THE AVAILABLE MOISTURE WILL BE BELOW
NORMAL ACROSS MUCH OF EASTERN BRASIL...FROM NEAR CEARA SOUTH INTO
RIO GRANDE DO SUL...WHILE AREAS OF MATO GROSSO AND GOIAS WILL HAVE
MUCH BELOW NORMAL MOISTURE DURING THE FORECAST PERIOD. OTHER AREAS
IN BRASIL WILL HAVE ABOVE NORMAL MOISTURE AS WELL. THE EASTERLY
WIND FLOW IN THE MID TO UPPER LEVELS WILL CAUSE THE RELATIVE
HUMIDITY TO INCREASE ACROSS PERU AND ECUADOR THIS
WEEKEND...CAUSING ABOVE NORMAL MOISTURE OVER THE AREA. OTHER AREAS
OF SOUTH AMERICA WILL HAVE A COMBINATION OF BELOW AND ABOVE NORMAL
MOISTURE...IN PARTICULAR URUGUAY WILL HAVE BELOW NORMAL MOISTURE
INTO THE WEEKEND...WHILE AND ATMOSPHERIC RIVER WILL BE MOVING INTO
SOUTHERN CHILE TODAY...INCREASING MOISTURE OVER THE AREA INTO
SOUTHERN ARGENTINA TODAY...DRYING UP FOR SATURDAY...THEN ANOTHER
ATMOSPHERIC RIVER WILL MOVE IN SUNDAY MORNING...INCREASING
MOISTURE INTO SOUTHERN ARGENTINA ONCE AGAIN. THIS RELATIVELY DEEP
MOISTURE MOVING INTO ARGENTINA ON SUNDAY WILL HELP THE DEVELOPMENT
OF THUNDERSTORMS OVER SOUTHERN PATAGONIA.


ALAMO...(WPC)