110
FXSA20 KWBC 211858
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
257 PM EDT MON OCT 21 2024
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 21 OCT 2024 AT 1900 UTC:
OF NOTE OVER THE NEXT SEVERAL DAYS...THE MADDEN-JULIAN OSCILLATION
IS EXPECTED TO REMAIN IN ITS CONVERGENT PHASE OVER THE
AMERICAS...PRESENTING MORE ISOLATED PRECIPITATION. HOWEVER...SOME
SYNOPTIC CONDITIONS OVER THE CONTINENT WILL FAVOR HEAVY
PRECIPITATION OVER THE NEXT SEVERAL DAYS.
ON MONDAY IN NORTHERN SOUTH AMERICA...THE UPPER LEVELS ARE SHOWING
A GENERALIZED RIDGING OVER THE REGION OF THE AMAZON IN PERU AND
WEST BRASIL...WITH A SHORT WAVE TROUGH PRESENT IN SOUTHERN PERU.
IN THE LOWER LEVELS...A PRESENCE OF LARGE AMOUNT OF AVAILABLE
MOISTURE IS EXPECTED TO CONVERGE DUE TO THE ADVECTION FROM THE
NORTH AND EAST. THE UPPER TROUGH WILL INTERACT WITH THE LOW LEVEL
CONVERGENCE ALONG THE ANDES MOUNTAINS IN PERU...WHERE EXPECT
MAXIMA OF 25-50MM IN NORTH-CENTRAL PERU. IN AMAZONAS-BRASIL...AND
INTO SOUTH PERU AND NORTH BOLIVIA...EXPECT MAXIMA OF 20-35MM. IN
BOLIVIA...THE SALLJ IS EXPECTED TO TRANSPORT MOISTURE INTO CENTRAL
PORTIONS OF THE COUNTRY AND FAVOR MAXIMA OF 25-50MM WITH A RISK OF
HEAVY THUNDERSTORM. ON TUESDAY...THE CONTINUED MOISTURE ADVECTION
IN THE AMAZON IS EXPECTED AS IT FLOWS FURTHER WEST AND FAVORS
MOISTURE CONVERGENCE ALONG THE ANDES MOUNTAINS IN PERU. THE UPPER
LEVEL TROUGH MEANDERS IN SOUTHERN PERU...WHILE INTERACTING WITH
THE MOISTURE CONVERGENCE IN THE LOWER LEVELS OF THE ATMOSPHERE.
FROM AMAZONAS-BRASIL...INTO ACRE...AND EASTERN PERU...EXPECT
MAXIMA OF 25-50MM. CENTRAL PERU CAN EXPECT MAXIMA OF 20-45MM. BY
WEDNESDAY...THE UPPER LEVEL TROUGH OVER PERU IS EXPECTED TO
WEAKEN...AS WELL AS THE AVAILABLE MOISTURE IN THE REGION IS
EXPECTED TO DECREASE. THESE CONDITIONS WILL FAVOR A DECREASE IN
TOTALS TO GENERALIZED MAXIMA OF 15-35MM FROM WESTERN BRASIL...TO
PERU...AND EXTREME NORTH BOLIVIA.
IN SOUTHERN BRASIL...A CUTOFF LOW IS PRESENT IN THE UPPER
LEVELS...IN ADDITION TO THE PASSING OF SHORTWAVE TROUGHS IN THE
MID LEVELS. OVER THE NEXT THREE DAYS...THIS UPPER TROUGH IS
EXPECTED TO MEANDER OVER SOUTHERN BRASIL AND PARAGUAY...BUT WILL
WEAKEN AND DECREASE THE DYNAMICS OVER THE REGION BY WEDNESDAY. IT
IS EXPECTED TO INTERACT WITH A POTENT RIDGE TO ITS EAST..FAVORING
DEEP CONVECTION. ON MONDAY...UPPER LEVEL DIVERGENCE ASSOCIATED
WITH THE UPPER TROUGH WILL FAVOR VENTILATION AND DEEP CONVECTION
FROM SOUTH PARA...TO GOIAS AND NORTH MINAS GERAIS. A GENERALIZED
MAXIMA OF 25-50MM IS EXPECTED...WITH LOCALIZED HIGHER AMOUNTS
POSSIBLE. IN THE SURROUNDING REGIONS EXPECT MAXIMA OF 20-35MM. ON
TUESDAY... THE UPPER RIDGE IS EXPECTED TO MOVE WESTWARD...WHILE IN
THE LOWER LEVELS...DRY AIR IS BEING ADVECTED INTO EASTERN BRASIL.
MOST OF THE MOISTURE WILL MOVE WEST INTO SOUTHWEST BRASIL. A
DECREASE IS EXPECTED IN THE REGION...WHERE MAXIMA OF 20-35MM ARE
EXPECTED FROM PARANA...TO SOUTHERN GOIAS. BY WEDNESDAY...SOUTHERLY
FLOW DOMINATES IN SOUTHERN BRASIL...BUT THE INTERACTIONS OF THE
UPPER RIDGE AND THE UPPER LEVEL TROUGH WILL ENHANCE CONVECTION IN
THE REGION. EXPECT MAXIMA OF 20-35MM FROM SOUTH SAO PAULO...AND
RIO DE JANEIRO.
IN THE CENTRAL PORTION OF THE CONTINENT...A CUTOFF LOW MEANDERS TO
THE WEST OF CHILE...SLOWLY ENTERING THE CONTINENT AS A RIDGE IS
BLOCKING ITS PASSAGE ON MONDAY. IN THE MID LEVELS...A SERIES OF
SHORTWAVE TROUGHS AR EXPECTED TO ADVENT VORTICITY IN CENTRAL
ARGENTINA. THE UPPER DIVERGENCE ASSOCIATED WITH THE UPPER TROUGH
WILL FAVOR SOME ASCENT IN THE REGION...WHERE NORTH-CENTRAL
ARGENTINA CAN EXPECT MAXIMA OF 20-45MM WITH RISK OF HEAVY
THUNDERSTORMS. ON TUESDAY...THE UPPER LEVEL TROUGH IS BEGINNING TO
ENTER FURTHER INTO ARGENTINA...AS THE DIVERGENT SIDE WILL CONTINUE
TO FAVOR DEEP CONVECTION. IN THE LOWER LEVELS...THE PRESSURES ARE
EXPECT TO DECREASE AND THE DEVELOPMENT OF A FRONTAL BOUNDARY IS
EXPECTED IN ASSOCIATION WITH THE UPPER TROUGH. MOISTURE FROM THE
TROPICS IS BEGINNING TO ENTER THE REGION OF NORTH ARGENTINA...AND
INCREASE IN PRECIPITATION IS EXPECTED. MAXIMA OF 35-70MM IS
EXPECTED IN CENTRAL ARGENTINA...INTO BUENOS AIRES. TO THE
NORTHWEST IN ARGENTINA...EXPECT MAXIMA OF 20-35MM. BY
WEDNESDAY...THE UPPER TROUGH BEGINS TO SPEED UP AS IT CROSSES THE
ANDES MOUNTAINS REGION AND IS EXPECTED IN NORTH CENTRAL ARGENTINA.
MOISTURE IS EXPECTED TO CONTINUE TRANSPORTING FROM THE NORTH...AND
THE FRONTAL BOUNDARY IS BEGINNING TO ADVANCE TO THE NORTH AND EAST
OVER NORTH ARGENTINA AND INTO URUGUAY. EXPECT MAXIMA OF 50-100MM
IN BUENOS AIRES...ENTRE-RIOS-ARGENTINA...AND URUGUAY WITH A SLIGHT
RISK OF SEVERE WEATHER. FROM FORMOSA...TO LA PAMPA EXPECT MAXIMA
OF 25-50MM WITH A MARGINAL RISK OF SEVERE WEATHER.
CASTELLANOS...(WPC)
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