316
FXSA20 KWBC 221926
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
325 PM EDT TUE OCT 22 2024
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 22 OCT 2024 AT 1930 UTC:
IN THE NORTHERN SECTOR OF SOUTH AMERICA...A SEGREGATED UPPER LOW
IS CENTERED IN WESTERN MATO GROSSO DO SUL AND IS MEANDERING OVER
EAST PARAGUAY AND INTO SOUTH MATO GROSSO AND SOUTH GOIAS. TO THE
NORTH AND EAST OF THE SEGREGATED LOW...A RIDGE OVER CENTRAL
BRASIL...WHERE INTERACTIONS WITH THE LOW IS FAVORING DIVERGENCE
ALOFT. TO THE EAST...A SHORT WAVE TROUGH IS DEVELOPING OVER
CENTRAL PERU...EXPECTED TO ENHANCE CONVECTION OVER THE FOOTHILLS
OF THE ANDES MOUNTAIN AND INTO SECTORS IN THE AMAZON BASIN. IN THE
LOWER LEVELS...THE CONVERGENCE OF MOISTURE OBSERVED IN WESTERN
AMAZONAS-BRASIL AND EAST PERU IS EXPECTED TO TRIGGER THE
CONVECTION THAT WILL BE ENHANCED BY THE UPPER TROUGH. DUE TO THE
CONVERGENT CONDITIONS IN THE UPPER ATMOSPHERE ASSOCIATED WITH THE
MADDEN-JULIAN OSCILLATION...THE THUNDERSTORMS WITH HEAVY
PRECIPITATION IS EXPECTED TO REMAIN ISOLATED TO SCATTERED ON
TUESDAY. FROM SOUTHERN COLOMBIA TO NORTH BOLIVIA...EXPECT
GENERALIZED MAXIMA OF 20-45MM WITH A CHANCE OF HIGHER
PRECIPITATION LOCALLY. IN CENTRAL EAST PERU EXPECT MAXIMA OF
30-60MM. OTHER REGIONS OF BRASIL EXPECT GENERALIZED MAXIMA OF
15-20 WITH HIGHER AMOUNTS POSSIBLE. ON WEDNESDAY...THE UPPER
TROUGH IS PERU IS EXPECTED TO INTERACT WITH RIDGING ALOFT THAT IS
RETROGRADING INTO PERU...WHERE IN THE LOWER LEVELS...MOISTURE
CONVERGENCE IS EXPECTED TO CONTINUE OVER THE REGION. TO THE
EAST...DRIER AIR IS BEING ADVECTED INTO CENTRAL BRASIL IN THE
LOWER LEVELS. THE EXCEPTION IS IN AMAPA AND PARA-BRASIL WHERE THE
TRADE WINDS ARE ADVECTING MOISTURE ALONG THE COASTS OF THE
AFOREMENTIONED BRASIL STATES. IN WEST AND CENTRAL BRASIL...THE
MOISTURE IS MOVING INTO THE REGION AND TROUGHS IN THE LOWER LEVELS
ARE FAVORING PRECIPITATION. THERE IS A DECREASE EXPECTED ON
WEDNESDAY...WHERE THE SEGREGATED LOW BEGINS TO WEAKEN. IN TERMS OF
PRECIPITATION...MAXIMA OF 20-45MM IN PERU...MAXIMA OF 20-35MM FROM
SOUTH COLOMBIA TO AMAZONAS-BRASIL...AS WELL AS FROM SOUTH GOIAS TO
SOUTH BRASIL. INTO THURSDAY...A NEW UPPER LEVEL TROUGH IS EXPECTED
TO APPROACHED THE WESTERN COAST OF PERU...YET A RIDGE IS EXPECTED
IN PLACE IN WESTERN BRASIL. MINIMAL INTERACTION IS EXPECTED AT
THIS TIME...HOWEVER...THE AMOUNT OF AVAILABLE MOISTURE IN PERU IS
EXPECTED TO PERSIST INTO THURSDAY. BY THIS TIME...A POTENT UPPER
TROUGH IS EXPECTED TO ENTER SOUTH BRASIL BY THURSDAY MORNING. A
FRONTAL BOUNDARY IS EXPECTED TO ARRIVE IN THE SAME LOCATION BY
THURSDAY EVENING. THIS WILL TRIGGER HEAVY PRECIPITATION IN
SOUTHERN BRASIL FROM SOUTH GOIAS/MINAS GERAIS...TO NORTH RIO
GRANDE SO SUL...WHERE EXPECT MAXIMA OF 30-60MM. MATO GROSSO DO SUL
CAN EXPECT MAXIMA OF 20-45MM...WHILE OTHER REGIONS OF SOUTH AND
CENTRAL BRASIL CAN EXPECT MAXIMA OF 20-35MM.
TO THE SOUTH...A SEGREGATED LOW IS MAKING ITS WAY INTO THE
CONTINENT TO THE WEST OF NORTH-CENTRAL CHILE...WHERE THE DIVERGENT
SIDE OF THE ASSOCIATED UPPER JET IS ENTERING THROUGH SAN
JUAN-ARGENTINA AND NORTH MENDOZA. AN INCREASE IS PRECIPITABLE
WATER IN CENTRAL ARGENTINA WILL FAVOR HEAVY PRECIPITATION OF
35-70MM WITH A MODERATE RISK OF SEVERE WEATHER. A MARGINAL RISK OF
SEVERE WEATHER AND MAXIMA OF 15-25MM ARE EXPECTED IN SAN
JUAN-ARGENTINA AND MENDOZA. ON WEDNESDAY...THE LOW IS EXPECTED TO
CONTINUE TO MOVE FURTHER EAST...WHILE A COUPLE-JET EFFECT IS
EXPECTED IN EAST-CENTRAL ARGENTINA AND EXTEND INTO URUGUAY BY THE
END OF THE FORECAST DAY. THE INCREASED AMOUNT OF AVAILABLE
MOISTURE CAN FAVOR MAXIMA OF 50-100MM IN URUGUAY...BUENOS
AIRES...AND ENTRE RIOS-ARGENTINA. FROM NORTHEAST ARGENTINA...ALONG
SANTA FE...AND SOUTHWARD INTO NORTH LA PAMPA REGION...THE EFFECTS
OF THE DIVERGENCE ALOFT AND THE AVAILABLE MOISTURE WILL FAVOR
MAXIMA OF 25-50MM. BY THURSDAY...THE SEGREGATED LOW TURNED UPPER
LEVEL TROUGH BECOMES NEGATIVELY TILTED OVER URUGUAY AND INTO SOUTH
BRASIL. A DECREASE IN MOISTURE IS EXPECTED...AND SUCH A MAXIMA OF
20-35MM IS EXPECTED IN
URUGUAY...CORRIENTES/MISIONES-ARGENTINA...AND PORTIONS OF SOUTH
PARAGUAY.
CASTELLANOS...(WPC)
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