081
FXSA20 KWBC 061927
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
227 PM EST WED NOV 06 2024
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 06 NOV 2024 AT 1930 UTC:
IN THE NORTHERN SECTOR OF THE CONTINENT...A POTENT UPPER RIDGE
EXTENDS OVER PERU...BOLIVIA...AND WEST BRASIL ON WEDNESDAY. THE
RIDGEÂBEGINS TO WEAKEN SLIGHTLY OVER THE DAY...ALLOWING FOR AN
UPPER TROUGH TO EXTEND INTO PORTIONS OF NORTH BOLIVIA AND SOUTH
PERU. IN THE LOWER LEVELS OF THE ATMOSPHERE...MOISTURE IS BEING
ADVECTED FROM THE NORTH AND IS EXPECTED TO CONVERGE ALONG THE
MOUNTAIN REGIONS IN PERU AND BOLIVIA. THE PRESENCE OF THE UPPER
TROUGH AND LOW LEVEL MOISTURE CONVERGENCE WILL PROVIDE VENTILATION
FOR DEEP CONVECTION IN REGIONS OF SOUTH PERU AND INTO NORTH
BOLIVIA. SIMILARLY...REGIONSÂOF MOISTURE CONVERGENCE AND THE
PRESENCE OF LOW LEVEL TROUGHS WILL CONTINUE OVER BRASIL...WHERE
INCREASED AMOUNTS OF PRECIPITATION TOTALSÂARE EXPECTED. THE
AVAILABLE MOISTURE IN THE REGION MAY NOT BE FULLY CAPTURED BY
MODEL GUIDANCE IN THE CENTRAL AND NORTH REGIONS OF SOUTH AMERICA.
PRECIPITATION TOTALS ARE EXPECTED TO BE HEAVY...WITH LOCALIZED
HIGHER AMOUNTS POSSIBLE ON WEDNESDAY. IN SOUTH BRASIL...A FRONTAL
BOUNDARYÂIS MAKING ITS WAY INTO RIO GRANDE SO SUL AND SANTA
CATARINA BY WEDNESDAY EVENING...WHERE ADDITIONAL PRECIPITATION IS
EXPECTED. ON THURSDAY...THE UPPER TROUGH CONTINUES ITS NORTH AND
EASTWARD MOVEMENT INTO EAST BOLIVIA AND SOUTH BRASIL...FAVORING
THE DEVELOPMENT OF LOWER PRESSURES IN THE LOWER LEVELS. FROM SOUTH
PERU...NORTH BOLIVIA...AND INTO SOUTH BRASIL. THIS TROUGHING IS
EXPECTED TO REFLECT IN THE 700 HPA AND 850 HPA LEVELS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE INTO FRIDAY...WITH A STRONGER
SIGNATURE IN THE LOWER LEVELS. THIS IS EXPECTED TO DEVELOP INTO
THE SOUTH ATLANTIC CONVERGENCE ZONE ON FRIDAY. WITH THE INCREASED
AMOUNTS OF MOISTURE CONVERGENCE ALONG THE SACZ AND ENHANCEMENT
FROM THE UPPER LEVEL CONDITIONS...HEAVY PRECIPITATION IS EXPECTED
IN PERU...BOLIVIA...AND SOUTH BRASIL FROM THURSDAY AND INTO
SATURDAY MORNING. IN TERMS OF PRECIPITATION...ON WEDNESDAY...THE
NORTH-CENTRAL REGION OF BRASIL CAN EXPECT MAXIMA OF
25-50MM...EXTENDING INTO NORTH BOLIVIA...AND SOUTH PERU. LOCALIZED
HIGHER AMOUNTS ARE POSSIBLE. HEAVY PRECIPITATION IS EXPECTED IN
SOUTH BOLIVIA WITH MAXIMA OF 25-50MM. MODEL GUIDANCE IS NOT
CAPTURING THE CURRENT SITUATION IN EAST PARAGUAY MATO GROSSO DO
SUL...WHERE A SLIGHT RISK OF SEVERE WEATHER IS PRESENT ACCORDING
TO SATELLITE IMAGERY. HEAVY PRECIPITATION HAS ALREADY BEEN
OBSERVED ON WEDNESDAY IN REGIONS OF PARAGUAY...AS SUCH A MAXIMA OF
30-60MM WITH HIGHER AMOUNTS POSSIBLE COULD BE EXPECTED. SIMILAR
AMOUNTS COULD BE SEEN IN PARANA AND SANTA CATARINA-BRASIL. ON
THURSDAY...THE DEVELOPING SACZ EXTENDS FROM SOUTH PERU TO SANTA
CATARINA/PARANA-BRASIL. NORTH BOLIVIA/SOUTH PERU CAN EXPECT MAXIMA
OF 40-80MM...WHILE SOUTH BOLIVIA INTO NORTH ARGENTINA CAN EXPECT
MAXIMA OF 25-50MM. SOUTH BRASIL CAN EXPECT MAXIMA OF 35-70MM. ON
FRIDAY...A MAXIMA OF 50-100MM COULD BE SEEN IN RIO DE JANEIRO/SAO
PAULO AS THE FRONTAL BOUNDARY AND SACZ ARE PRESENT. MAXIMA OF
35-70MM ARE EXPECTED IN EAST PERU INTO EAST
AMAZONAS/ACRE-BRASIL...AS WELL AS FROM MATO GROSSO TO NORTH SAO
PAULO. HIGHER AMOUNTS ARE POSSIBLE AND MAXIMA WILL BE UPDATED AS
MORE CONFIDENCE IS GAINED THROUGH MODEL GUIDANCE.
IN THE SOUTHERN REGION OF THE CONTINENT...AN UPPER TROUGH IS
DOMINATING THE UPPER ATMOSPHERE WITH THE PRESENCE OF SHORT WAVE
TROUGHS EMBEDDED IN THE MID TO UPPER LEVELS. THESE SHORTWAVE
TROUGHS WILL FAVOR ASCENT OVER THE REGION...INCREASING THE CHANCE
FOR THUNDERSTORM ACTIVITY. HOWEVER...OVER THE NEXT SEVERAL
DAYS...MOISTURE IS LIMITED IN PORTIONS OF ARGENTINA. THE EXCEPTION
IS SOUTHERN CHILE...WHERE THE PRESENCE OF FRONTAL BOUNDARIES WITH
INCREASED MOISTURE WILL INTERACT WITH THE UPPER LEVEL DYNAMICS TO
INCREASE THE CHANCE OF PRECIPITATION OVER THE NEXT THREE DAYS.Â
ON WEDNESDAY...CENTRAL ARGENTINA CAN EXPECT MAXIMA OF 15MM WITH A
MARGINAL RISK OF SEVERE WEATHER WITH THE PASSING OF SHORT WAVE
TROUGHS IN THE AREA. IN SOUTHERN CHILE EXPECT MAXIMA OF 15-20MM IN
MAGALLANES. ON THURSDAY...AND INCREASED AMOUNT OF AVAILABLE
MOISTURE WILL FAVOR MAXIMA OF 15-30MM IN NORTH ARGENTINA...WHILE
MAXIMA BELOW 25MM WITH A MARGINAL RISK OF SEVERE WEATHER ARE
EXPECTED IN CENTRAL ARGENTINA. SIMILARLY...MAXIMA OF 20-35MM ARE
EXPECTED IN SOUTH AYSEN AND MAGALLANES WITH THE ENTRANCE OF A
FRONTAL BOUNDARY...AND LESS THAN 15MM ARE EXPECTED FROM SOUTH LOS
LAGOS TO NORTH AYSEN. ON FRIDAY...MOISTURE BEGINS TO DECREASE OVER
ARGENTINA AS THE SACZ TO THE NORTH IS ESTABLISHED. MAXIMA BELOW
15MM ARE EXPECTED WITH A SLIGHT RISK OF SEVERE WEATHER IS EXPECTED
IN CENTRAL ARGENTINA. HOWEVER...SOUTH CHILE CAN EXPECT ADDITIONAL
MOISTURE IN ASSOCIATION WITH THE PASSING OF TWO FRONTAL BOUNDARIES
FROM ARAUCANA TO NORTH AYSEN...WHERE EXPECT MAXIMA OF 20-40MM. TO
THE SOUTH...EXPECT MAXIMA BELOW 15MM WITH A RISK OF THUNDERSTORM
ACTIVITY.
CASTELLANOS...(WPC)
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