460
FXSA20 KWBC 062014
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
314 PM EST MON JAN 06 2025
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 06 JAN 2025 AT 2015 UTC:
THE BOLIVIAN HIGH IS CENTERED OVER BOLIVIA AND IS EXTENDING AS FAR
SOUTH AS NORTH ARGENTINA AND INTO NORTH AND CENTRAL BRASIL. THIS
FEATURE IS EXPECTED TO MEANDER OVER THE REGION OVER THE NEXT THREE
DAYS AND INTERACT WITH AN UPPER TROUGH OVER EAST BRASIL. THIS
REGION OF BRASIL WILL SEE DIFFLUENCE IN THE MID TO UPPER LEVELS
DUE TO THE INTERACTION BETWEEN THE BOLIVIAN HIGH AND THE MID TO
UPPER LEVEL TROUGH. IN THE LOWER LEVELS IN NORTH AND EAST
BRASIL...TROUGHS ARE BEING ADVECTED SOUTH AND WESTWARD AND ARE
BEING INFLUENCED BY THE UPPER LEVEL VENTILATION. THIS IS
ACTIVATING DEEP CONVECTION IN BRASIL...WHERE SCATTERED HEAVY
PRECIPITATION IS EXPECTED OVER THE NEXT THREE DAYS IN CENTRAL
BRASIL. ON MONDAY...EXPECT MAXIMA OF 35-70MM FROM PARA TO MATO
GROSSO DO SUL/NORTH SAO PAULO. ON TUESDAY THERE IS LOW CONFIDENCE
IN MODEL GUIDANCE IN THE LOCATION AND AMOUNT OF PRECIPITATION IN
THE AFOREMENTIONED REGION. FOR NOW THE FORECAST AMOUNT IS OF
20-45MM WITH A POTENTIAL FOR LOCALIZED HIGHER AMOUNTS. ON
WEDNESDAY...CONDITIONS ARE CONSISTENT WHEN COMPARING THE MODEL
GUIDANCE...WHERE THE UPPER LEVEL DIVERGENCE WILL FAVOR DEEP
CONVECTION IN THE SAME REGION. EXPECT MAXIMA OF 30-60MM WITH A
CHANCE FOR HIGHER TOTALS LOCALLY.
IN SOUTHERN BRASIL...THE PRESENCE OF THE UPPER TROUGH BASE AND A
FRONTAL BOUNDARY AND PREFRONTAL TROUGHS ARE INTERACTING WITH THE
AVAILABLE MOISTURE BEING ADVECTED FROM THE NORTH. WITH THE
CONDITIONS REMAINING SIMILAR WITH THE UPPER LEVEL TROUGH OVER
SOUTH BRASIL OVER THE NEXT THREE DAYS...THE UPPER LEVEL SUPPORT IS
EXPECT TO FAVOR HEAVY PRECIPITATION. ON MONDAY EXPECT MAXIMA OF
30-60MM IN MINAS GERAIS...RIO DE JANEIRO...AND ESPIRITO SANTO. ON
TUESDAY...EXPECT MAXIMA OF 35-70MM FROM MATO GROSSO DO SUL TO RIO
DE JANEIRO AND ESPIRITO SANTO. ON WEDNESDAY...THE FRONTAL BOUNDARY
IS FAVORING WINDS FROM THE SOUTH INTO SOUTH SAO PAULO...WHERE
MOIST ONSHORE FLOW IS EXPECTED WEDNESDAY INTO THURSDAY. FROM THE
NORTH..MOISTURE CONTINUES TO PROPAGATE INTO SOUTHERN BRASIL. IN
THE MID TO UPPER LEVELS...AN EMBEDDED SHORTWAVE TROUGH IS EXPECTED
OVER SAO PAULO AND INTO RIO DE JANEIRO AT AROUND THE SAME TIME.
THIS WILL FAVOR CONDITIONS FOR DEEP CONVECTION AND HEAVY
PRECIPITATION OF MAXIMA OF 50-100MM IN ESPIRITO SANTO AND RIO DE
JANEIRO. MAXIMA OF 20-35MM ARE EXPECTED IN SAO PAULO. MINAS GERAIS
CAN ALSO EXPECT MAXIMA OF 40-80MM.
OVER BOLIVIA AND PERU...MOISTURE IS BEING ADVECTED INTO THE
REGION...CONVERGING AT THE ANDES MOUNTAINS. ON MONDAY...EXPECT
MAXIMA OF 30-60MM FROM CENTRAL-SOUTH PERU INTO BOLIVIA...AND
ACRE-BRASIL. MAXIMA OF 20-45MM ARE EXPECTED IN BOLIVIA. WHILE THE
MOUNTAIN REGIONS OF PERU AND BOLIVIA CAN EXPECT MAXIMA OF 15-30MM.
ON TUESDAY...MOIST AIR CONTINUES TO MOVE INTO THE REGION...AND
OROGRAPHIC LIFT FAVOR DEEP CONVECTION IN PERU AND BOLIVIA. EXPECT
MAXIMA OF 30-60MM IN SOUTH PERU AND CENTRAL BOLIVIA. SIMILAR
AMOUNTS ARE EXPECTED IN CENTRAL BOLIVIA AND SOUTH-CENTRAL PERU
WITH THE CONTINUED EFFECTS OF MOISTURE CONVERGING ALONG THE ANDES
AND THE OROGRAPHIC LIFT.
IN THE SOUTHERN PORTION OF THE CONTINENT...THE UPPER LEVEL TROUGHS
ARE STAYING SOUTHWARD AS THE BOLIVIAN HIGH IS EXTENDING SOUTHWARD
INTO ARGENTINA ON MONDAY. ON TUESDAY AND WEDNESDAY...THE BOLIVIAN
HIGH MEANDERS SLIGHTLY NORTHWARD AND THIS ALLOWS FROM AN UPPER
TROUGH TO ENTER THE SOUTH-CENTRAL REGIONS OF CHILE AND ARGENTINA.
THIS WILL ASSIST IN DESTABILIZING THE ATMOSPHERE AS WELL AS THE
ENTRANCE OF FRONTAL BOUNDARIES INTO THE REGION. ALTHOUGH THE
AMOUNT OF AVAILABLE MOISTURE IS EXPECTED TO BE ELEVATED... UPPER
LEVEL CONDITIONS ARE NOT AS FAVORABLE FOR VENTILATION AND THUS
PRECIPITATION VALUES ARE EXPECTED TO REMAIN BELOW MODERATE. ON
MONDAY...SOUTH AYSEN AND NORTH MAGALLANES CAN EXPECT MAXIMA OF
15-25MM...SIMILAR AMOUNTS ARE EXPECTED IN CENTRAL ARGENTINA WITH A
SLIGHT RISK OF SEVERE WEATHER. ON TUESDAY...SOUTH CHILE CAN EXPECT
MAXIMA BELOW 15MM. FROM MENDOZA TO SAN JUAN-ARGENTINA...EXPECT
MAXIMA OF 15-25MM WITH A MODERATE RISK OF SEVERE WEATHER WITH THE
PRESENCE OF THE UPPER LEVEL TROUGH. SIMILARLY ON
WEDNESDAY...NORTHWEST ARGENTINA CAN EXPECT MAXIMA OF 20-35MM WITH
A MODERATE RISK OF SEVERE WEATHER AS MOISTURE FROM THE NORTH IS
BEING ADVECTED. FRONTAL BOUNDARIES OVER SOUTH CHILE WILL FAVOR
MAXIMA OF 15-20MM WITH A RISK OF THUNDER ACTIVITY.
CASTELLANOS...(WPC)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page