Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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916 FXSA20 KWBC 081839 PMDSA SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 139 PM EST FRI NOV 08 2024 GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/ NOTE: THE NEXT UPDATE TO THE SOUTH AMERICAN FORECAST BULLETIN WILL BE AVAILABLE ON 12 NOVEMBER 2024. SOUTH AMERICAN FORECAST BULLETIN FOR 08 NOV 2024 AT 1840 UTC: IN SOUTH AMERICA ON FRIDAY...THE NORTHERN REGION WILL BE IN THE PRESENCE OF THE MEANDERING UPPER HIGH PRESSURE SYSTEM...THAT EXTENDS FROM THE EAST PACIFIC...AND ELONGATES THROUGH CENTRAL BRASIL. THE TROUGHING PATTERN IN THE SOUTHERN REGION IS VERY PROGRESSIVE...AND ARE EXPECTED TO PROPAGATE QUICKLY OVER THE NEXT FEW DAYS. THE CURRENT TROUGH THAT EXTENDS ARE FAR NORTH AS CENTRAL BOLIVIA...AND SOUTH BRASIL IS ASSOCIATED WITH THE DEVELOPMENT OF THE SOUTH ATLANTIC CONVERGENCE ZONE (SACZ) THAT IS FAVORING DEEP CONVECTION FROM SOUTH BRASIL INTO WESTERN PORTIONS OF THE COUNTRY...INTO BOLIVIA...AND SOUTH PERU. THE ELEVATED AMOUNTS OF PRECIPITABLE WATER IS STRENGTHENING THE POSSIBILITY OF HIGHER PRECIPITATION OVER THE REGION. ON SATURDAY AND SUNDAY THE BOLIVIAN HIGH IS PRESENT AND EXTENDS FROM PERU INTO SOUTH CENTRAL BRASIL. THIS BLOCKING PATTERN IS EXPECTED TO THE POTENT AND ENHANCE THE JET TO THE SOUTH OVER ARGENTINA WITH THE APPROACHING WIDE TROUGH OVER THE SOUTHERN CONE OF THE CONTINENT. TO THE EAST IN BRASIL...THE UPPER TROUGH ASSOCIATED WITH THE SACZ DEVELOPMENT EXTENDS TROUGH THE SOUTH AND EASTERN PORTION OF THE COUNTRY...AS THE BOLIVIAN HIGH DOMINATES AND PUSHES INTO THE REGION IN THE BEGINNING OF NEXT WEEK. THE PRESENCE OF THE SACZ IS EXPECTED TO REMAIN OVER THE WEEKEND...WEAKENING ON SUNDAY INTO MONDAY AND EXPECTED MOSTLY IN THE EASTERN PORTION OF BRASIL. THE HEAVIER PRECIPITATION IS EXPECTED ALONG THE COASTS OF SAO PAULO...RIO DE JANEIRO...AND ESPIRITO SANTO...AS WELL AS INTO MINAS GERAIS OVER THE NEXT THREE DAYS. PRECIPITATION TOTALS OF 50-100MM ARE EXPECTED WITH POTENTIAL FOR HIGHER AMOUNTS LOCALLY. WITH THE SACZ OVER THE REGION...LOCALIZED HIGHER AMOUNTS ARE ALSO POSSIBLE FROM PERU THROUGH BOLIVIA...AND INTO WEST AND SOUTH BRASIL. IN THE SOUTHERN CONE OF THE CONTINENT...THE POTENT UPPER RIDGE FROM THE NORTH BEINGS TO EXTEND INTO PORTIONS OF NORTH CHILE AND ARGENTINA...ENHANCING THE UPPER JET OVER CENTRAL CHILE WITH THE PASSING UPPER TROUGH TO THE SOUTH. IN THE MID LEVELS...SHORT WAVE TROUGHS ARE EXPECTED TO PROPAGATE THROUGHOUT THE CENTRAL AND SOUTHERN REGION OF THE COUNTRY AND INTO PORTIONS OF CENTRAL ARGENTINA SATURDAY AND SUNDAY. WITH THE PASSING FRONTAL BOUNDARIES ACTING AS TRIGGERS...THE POTENTIAL FOR SEVERE WEATHER IS EXPECTED IN CENTRAL ARGENTINA ON FRIDAY AND SATURDAY...AND WILL PROPAGATE INTO NORTH ARGENTINA BY SUNDAY...WITH A SLIGHT RISK OF SEVERE WEATHER. WITH THE SACZ WEAKENING IN BOLIVIA AND WEST BRASIL...AND INCREASING MOISTURE IN THE REGION FROM THE NORTH...EXPECT PRECIPITATION AMOUNTS TO INCREASE BY SUNDAY. IN SOUTHERN CHILE...THE ENTRANCE OF FRONTAL BOUNDARIES WILL FAVOR THE INCREASE OF MOISTURE IN THE REGION AND PRECIPITATION IS EXPECTED OVER THE NEXT THREE DAYS WITH THE ASSISTANCE FROM THE UPPER JET DYNAMICS. CASTELLANOS...(WPC) $$