195
FXSA20 KWBC 041920
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
219 PM EST MON NOV 04 2024
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 04 NOV 2024 AT 1920 UTC:
A POTENT BOLIVIAN HIGH IS SITUATED OVER PERU...CENTRAL
BRASIL...AND INTO BOLIVIA...REACHING NORTH PARAGUAY ON MONDAY.
THIS HIGH PRESSURE SYSTEM IS FAVORING A BLOCKING PATTERN OF UPPER
LEVEL TROUGHS THAT ARE PROPAGATING OVER REGIONS OF SOUTHERN SOUTH
AMERICA. IN THE LOWER LEVELS...THE PRESENCE OF MOISTURE IN THE
CENTRAL REGIONS OF THE CONTINENT WILL FAVOR SCATTERED
THUNDERSTORMS IN BRASIL...WHERE THE TRADE WINDS ARE CONVERGING.
THE MOISTURE TRANSPORT FROM THE TROPICAL REGIONS IN NORTH SOUTH
AMERICA IS REACHING FROM COLOMBIA/VENEZUELA TO NORTH PARAGUAY
ALONG THE ANDES MOUNTAINS OVER THE NEXT SEVERAL DAYS. IT IS
EXPECTED THAT THE MOISTURE WILL CONVERGE ALONG THE MOUNTAIN RANGE
FAVORING DEEP CONVECTION ALONG THE REGION AND CONVERGE SOUTHWARD
INTO NORTH ARGENTINA WITH A FRONTAL BOUNDARY ON MONDAY. OVER THE
NEXT SEVERAL DAYS THE MOIST TRANSPORT IS EXPECT TO INCREASE THE
AMOUNT OF AVAILABLE MOISTURE AND INTERACT WITH THE PRESENCE OF AN
UPPER LEVEL TROUGH THAT WILL ASSIST IN ADVANCING A FRONTAL
BOUNDARY INTO REGIONS OF BOLIVIA...PARAGUAY...AND SOUTH BRASIL BY
WEDNESDAY. THE IN ADDITION...THE UPPER RIDGE WILL BEGIN TO WEAKEN
AND ALLOW FOR THE UPPER TROUGHS TO REACH FURTHER NORTH INTO SOUTH
PERU...SOUTH BOLIVIA...AND THE PARAGUAY/BRASIL BORDER REGION. THE
DIVERGENT SIDE OF THE UPPER TROUGH WILL FAVOR DEEP CONVECTION IN
THE CENTRAL PORTIONS OF THE CONTINENT.
IN TERMS OF PRECIPITATION...ON MONDAY EXPECT MAXIMA OF 30-60MM
WITH A SLIGHT RISK OF SEVERE WEATHER IN THE CHACO REGION OF
ARGENTINA...AND MAXIMA OF 25-50MM IN SOUTH BOLIVIA/NORTH PARAGUAY.
MAXIMA OF 30-60MM ARE EXPECTED FROM GOIAS TO SAO PAULO WHERE A
REGION IS CONVERGING WITH INCREASED AMOUNT OF MOISTURE. SCATTERED
MAXIMA OF 20-45MM ARE EXPECTED ELSEWHERE IN BRASIL WHERE VARIOUS
REGIONS OF MOISTURE CONVERGENCE ARE ALSO EXPECTED...AND HIGHER
AMOUNTS OF ISOLATED MAXIMA ARE EXPECTED. ON TUESDAY...THE FRONTAL
BOUNDARY IS EXPECTED TO ADVANCE INTO BOLIVIA...ALONG PARAGUAY AND
INTO SANTA CATARINA/RIO GRANDE DO SUL. THIS WILL TRIGGER MAXIMA OF
30-60MM IN CENTRAL BOLIVIA...AND MAXIMA OF 25-50MM IN SOUTH
BOLIVIA. THE CHACO REGION OF ARGENTINA CAN FAVOR MAXIMA OF 20-45MM
WITH MARGINAL RISK OF SEVERE WEATHER. ALONG THE FRONTAL BOUNDARY
IN SOUTH PARAGUAY/PARANA EXPECT MAXIMA OF 20-35MM WITH MARGINAL
RISK OF SEVERE WEATHER. SCATTERED SHOWERS CONTINUE IN BRASIL WHERE
EXPECT MAXIMA OF 30-60MM IN GOIAS AND MINAS GERAIS WITH THE
CONTINUED PRESENCE OF TROUGHS AND INCREASED MOISTURE CONVERGENCE.
SIMILARLY...EXPECT GENERALIZED MAXIMA OF 20-45MM IN PARA...EAST
AMAZONS-BRASIL...AND NORTH MATO GROSSO. CENTRAL PERU WILL SEE AN
INCREASE IN PRECIPITATION AS MOISTURE CONVERGES ALONG THE ANDES.
THE REGION CAN EXPECT MAXIMA OF 20-35MM. BY WEDNESDAY...THE
FRONTAL BOUNDARY IS WEAKENED...WHILE THE REMNANTS ARE FAVORING
MAXIMA OF 30-60MM FROM MATO GROSSO DO SUL TO SAO PAULO...AS WELL
AS FROM SOUTH PERU INTO CENTRAL BOLIVIA. SIMILAR AMOUNTS ARE
EXPECTED IN SOUTH BOLIVIA INTO EXTREME NORTH SALTA-ARGENTINA.
GENERALIZED MAXIMA OF 20-35MM ARE EXPECTED IN BRASIL WITH THE
PRESENCE OF TROUGHS IN THE TRADE WINDS. SIMILAR AMOUNTS ARE
EXPECTED IN CENTRAL PERU.
IN THE SOUTHERN PORTION OF THE CONTINENT...THE PRESENCE OF A WIDE
UPPER TROUGH WITH VARIOUS SHORT WAVE TROUGHS EMBEDDED IN THE
SYSTEM ARE PROPAGATING OVER CHILE AND ARGENTINA ON MONDAY. A
SHORTWAVE TROUGH ENTERS THE SUR AND AUSTRAL REGIONS OF
CHILE...ASSISTING WITH LIFT AS AN ATMOSPHERIC RIVER IS EXPECTED TO
ENTER THE SOUTHERN REGION OF CHILE AS WELL. INCREASED AMOUNT OF
PRECIPITABLE WATER ON MONDAY WILL FAVOR PRECIPITATION TOTALS OF
20-35MM FROM AYSEN TO NORTH MAGALLANES WITH A RISK OF THUNDERSTORM
ACTIVITY. LOCALIZED HIGHER AMOUNTS COULD BE EXPECTED AS THE
DYNAMIC IS FAVORABLE OVER THE REGION ON MONDAY. ON TUESDAY...THE
ATMOSPHERIC RIVER CONTINUES ITS MOVEMENT NORTHWARD AND A DECREASE
IN THE AVAILABLE MOISTURE ASSOCIATED WITH IT IS ALSO FAVORING A
SLIGHT DECREASE IN PRECIPITATION FOR TUESDAY. EXPECT MAXIMA OF
15-30MM FROM SOUTH LOS LAGOS TO AYSEN WHILE NORTH MAGALLANES CAN
EXPECT MAXIMA BELOW 10MM WITH A RISK OF THUNDERSTORMS. TO THE
EAST...THE PRESENCE OF THE ASSOCIATED FRONTAL BOUNDARY IN SANTA
CRUZ-ARGENTINA WILL FAVOR MAXIMA BELOW 15MM WITH A MARGINAL RISK
OF SEVERE WEATHER. THE CROSSING OF THE SHORT WAVE TROUGHS IN THE
UPPER LEVELS WILL FAVOR FRONTOGENESIS OVER REGIONS OF LA
PAMPA-ARGENTINA WHICH CAN EXPECT MAXIMA BELOW 15MM. ON
WEDNESDAY...THE ATMOSPHERIC RIVER IS EXPECTED TO WEAKEN AND MOVE
FURTHER NORTH. MAXIMA IN THE SOUTHERN CONE OF THE CONTINENT IS
ASSOCIATED WITH A WEAK FRONTAL SYSTEM FAVORING MAXIMA OF 15MM WITH
MOUNTAIN SNOW.
CASTELLANOS...(WPC)
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