181
FXSA20 KWBC 141940
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
339 PM EDT WED AUG 14 2024
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SOUTH AMERICAN FORECAST BULLETIN FOR 14 AUG 2024 AT 1940 UTC:
ON WEDNESDAY...THE SOUTHERN CONE OF THE CONTINENT IS SEEING THE
PRESENCE OF A WIDE UPPER LEVEL JET....ASSOCIATED WITH THE COUPLING
OF THE NORTH AND SOUTH POLAR JETS...FROM CHILE INTO ARGENTINA. TO
THE NORTH OF THE JETS...A RIDGE IS PROPAGATING FROM NORTHERN
CHILE....ARGENTINA...AND SOUTH BRASIL/URUGUAY. THIS RIDGE IS
FAVORING DRIER CONDITIONS OVER THE REGION AND IT WILL BE PRESENT
INTO THURSDAY...UNTIL IT MOVES EAST OVER THE SOUTH ATLANTIC OCEAN.
A RIDGE PATTERN IS ALSO EXPECTED OVER THE TROPICAL SOUTH AMERICA
REGION...INHIBITING THE POSSIBILITY FOR HEAVIER PRECIPITATION IN
THE REGION. WHILE TROUGHS AND DISTURBANCES ALONG THE TRADES WILL
FAVOR AN INCREASE IN PRECIPITABLE WATER IN THE LOWE LEVELS OF THE
ATMOSPHERE. IN THE LOWER LEVELS...THE PRESENCE OF FRONTAL
BOUNDARIES IN CHILE AND EASTERN BRASIL WILL BE THE TRIGGERS FOR
PRECIPITATION IN THE AFOREMENTIONED REGIONS. INCREASED ONSHORE
FLOW WILL FAVOR MOISTURE CONVERGENCE IN EASTERN BAHIA-BRASIL AND
IN THE ZONA SURE AND NORTH ZONA AUSTRAL CHILE. THE IN TERMS OF
PRECIPITATIONS...FROM SOUTHERN COLOMBIA...TO AMAZONAS-BRASIL...AND
INTO SOUTHERN PARA...EXPECT GENERAL MAXIMA OF 15-30MM. DUE TO THE
STATIONARY FRONT IN EASTERN BAHIA...EXPECT MAXIMA OF 20-35MM. IN
SOUTHERN CHILE...MAXIMA OF 15-20MM ARE FORECAST.
INTO THURSDAY...THE COUPLING OF THE UPPER LEVEL JETS OVER CENTRAL
CHILE WILL FAVOR UPPER LEVEL DIVERGENCE AND ENHANCE THE
PRECIPITATION OVER THE REGION...WITH THE ENTRANCE OF THE COLD
FRONT IN MAGALLANES BY THURSDAY EVENING. THE AMOUNT OF AVAILABLE
MOISTURE ASSOCIATED WITH THE FRONT WILL TRIGGER MAXIMA OF 15-25MM.
TO THE NORTH...THE STATIONARY FRONT IN EAST BAHIA WILL BEGIN TO
WEAKEN...YET ONSHORE FLOW INTO THE BAHIA REGION ARE EXPECTED TO
FAVOR MAXIMA OF 15-20MM. A NOTICEABLE DECREASE IN PRECIPITATION IS
EXPECTED TO CONTINUE INTO FRIDAY FOR EAST BAHIA. IN NORTHERN SOUTH
AMERICA...DRIER AIR IS EXPECTED TO BE ADVECTED IN THE TRADE
WINDS...WHICH WILL REFLECT IN THE AMOUNTS OF PRECIPITATION FROM
SOUTHERN COLOMBIA INTO AMAZONAS-BRASIL AND WEST PARA. WITH THE
ASSISTANCE OF THE UPPER LEVEL RIDGE CONTINUING TO INHIBIT
CONVECTION OVER THE REGION...EXPECT GENERALIZED MAXIMA IN THE
RANGE OF 15-25MM.
ON FRIDAY...THE UPPER LEVEL JET OVER CENTRAL ARGENTINA IS
EXPANDING OVER THE REGION AND FAVORING THE ENHANCEMENT OF A
FRONTAL BOUNDARY THAT IS EXPECTED TO PROPAGATE FROM BUENOS
AIRES/WEST URUGUAY ON THURSDAY TO SOUTHERN BRASIL BY FRIDAY
EVENING. ALTHOUGH THERE IS SUPPORT FOR FURTHER ENHANCEMENT AND
VENTILATION ALOFT...THE ABSENCE OF AVAILABLE MOISTURE WILL INHIBIT
SIGNIFICANT PRECIPITATION. IN SOUTH AND CENTRAL CHILE THE PASSAGE
OF A COLD FRONT WILL FAVOR MAXIMA OF 15MM...AS THIS FRONT WILL NOT
BE ACCOMPANIED BY SIGNIFICANT AMOUNTS OF MOISTURE. SIMILARLY...IN
EASTERN BAHIA...DUE TO THE LOW AMOUNTS OF MOISTURE IN THE
REGION...AND BECAUSE THE FRONTAL BOUNDARY IS WEAKENING...MAXIMA
FOR REGION OF BAHIA ARE EXPECTED BELOW 10MM. FROM
COLOMBIA...ECUADOR...AND NORTH PERU...AS WELL AS...SOUTHERN
AMAZONAS-BRASIL...AND NORTH RONDONIA...EXPECT MAXIMA BELOW
15MM...DUE TO THE GENERALIZED DECREASE OF MOISTURE IN THE LOWER
LEVELS OF THE ATMOSPHERE.
ACOSTA...(WPC)
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