Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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668 FXSA20 KWBC 141838 PMDSA SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 138 PM EST THU NOV 14 2024 GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/ SOUTH AMERICAN FORECAST BULLETIN FOR 14 NOV 2024 AT 1830 UTC: IN THE NORTHERN PORTION OF SOUTH AMERICA...THE UPPER RIDGE/BOLIVIAN HIGH CONTINUES TO MEANDER OVER THE WESTERN PORTION AND EXTENDS INTO CENTRAL PORTIONS OF BRASIL. IN THE SOUTHERN PORTIONS OF BRASIL...A TROUGH IN THE UPPER LEVELS...EXPECTED TO DISSIPATE BY THURSDAY AND BEING REPLACED BY ANOTHER TROUGH BY FRIDAY...ENHANCED BY THE STRENGTHENING UPPER RIDGE OVER THE NORTH SOUTH AMERICA REGION. IN THE LOWER LEVELS THE EASTERLY TRADE WINDS ARE CONVERGING ALONG WEST AND CENTRAL BRASIL...WHERE THE AMOUNT OF PRECIPITABLE WATER IS EXCEEDING 50MM IN THE MAJORITY OF THE AREA. THESE CONDITIONS WILL FAVOR INCREASED MOISTURE CONVERGENCE OVER BRASIL...IN TURN FAVORING HEAVY PRECIPITATION ON THURSDAY. AS THE TRADE WINDS CONTINUE PROPAGATING THE LOW LEVEL TROUGHS FURTHER WEST...SIMILAR CONDITIONS ARE EXPECTED TO CONTINUE INTO WEST BRASIL...AND WILL PERSIST IN THE SOUTHERN PORTIONS OF THE COUNTRY. ALONG THE CORDILLERA IN PERU AND BOLIVIA INTERACTIONS WITH THE TERRAIN WILL FAVOR MODERATE PRECIPITATION IN THE HIGHER ELEVATIONS. ON SATURDAY...THE CONDITIONS CONTINUE MOVING TO THE WEST AND THE HEAVIER PRECIPITATION IS EXPECTED IN PERU...NORTH BOLIVIA...AND WEST/SOUTH BRASIL. IN SOUTHERN BRASIL...THE UPPER TROUGH STRENGTHENS AND FAVOR THE RISK OF MARGINAL RISK OF SEVERE WEATHER. IN TERMS OF PRECIPITATION...ON EXPECT MAXIMA OF 35-70MM FROM MINAS GERAIS TO PARA-BRASIL...WHILE MAXIMA OF 25-50MM ARE EXPECTED FROM MATO GROSSO TO WEST PARA AND EAST AMAZONAS. THESE REGIONS COULD SEE ISOLATED AMOUNTS THAT ARE HIGHER. IN THE WESTERN SIDE OF THE CONTINENT EXPECT MAXIMA OF 20-45MM IN CENTRAL PERU AND NORTH PERU/ECUADOR AND INTO SOUTH COLOMBIA. ON FRIDAY...THE MAXIMA OF 40-80MM AR EXPECTED FROM SOUTH PARA INTO MATO GROSSO...AND AS SOUTH AS GOIAS. MAXIMA OF 30-60MM ARE EXPECTED IN AMAZONAS-BRASIL...RONDONIA...AND WEST PARA...INTO SAO PAULO. OTHER REGIONS THAT WILL SEE MODERATE AMOUNTS ARE CENTRAL PERU WITH MAXIMA OF 20-45MM...AND SOUTH PERU INTO WEST BOLIVIA WITH MAXIMA OF 20-35MM. ON SATURDAY...GENERALIZED MAXIMA OF 30-70MM ARE EXPECTED FROM AMAZONAS-BRASIL THROUGH MATO GROSSO...AND INTO SAO PAULO. THE POSSIBILITY FOR HIGHER AMOUNTS OF PRECIPITATION ARE EXPECTED. IN THE SOUTHERN SECTION OF THE CONTINENT...A FRONTAL BOUNDARY HAS ENTERED CHILE AND ARGENTINA AND WILL EXTEND INTO THE ATLANTIC OCEAN BY THURSDAY EVENING. AN ASSOCIATED ATMOSPHERIC RIVER IS EXPECTED TO BRING PRECIPITABLE WATER AMOUNTS THAT ARE HIGHER THAN 25-30MM IN LOS LAGOS AND NORTH AYSEN...WHERE IT WILL INTERACT WITH THE TERRAIN. ENHANCED BY THE UPPER LEVEL JET IN THE REGION...EXPECT MAXIMA OF 25-50MM IN THE AFOREMENTIONED REGION ON THURSDAY. FROM THE WESTERN COAST OF LOS LAGOS TO SOUTH AYSEN EXPECT MAXIMA OF 20-35MM WITH A RISK OF THUNDERSTORM ACTIVITY. ON FRIDAY...A DECREASE IN PRECIPITATION IS EXPECTED WHEN THE AMOUNT OF AVAILABLE MOISTURE DECREASES IN LOS LAGOS AND AYSEN. IN MAGALLANES...A MOISTURE PLUME IS ENTERING THE REGION THAT WILL FAVOR MAXIMA OF 20-35MM ON FRIDAY. ON SATURDAY...THE ENTRANCE OF A FRONTAL BOUNDARY WILL FAVOR MAXIMA OF 20-35MM WHILE A WEAK JET IS EXPECTED TO ASSIST WITH THE ENHANCED DIVERGENCE OVER THE REGION. CASTELLANOS...(WPC) $$