SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
155 PM EDT FRI JUL 05 2024

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SOUTH AMERICAN DISCUSSION FOR JULY 5TH AT 17 UTC: THE ANTARCTIC
INCURSION IN THE SOUTHERN CONE CONTINUES MOVINT INTO THE SOUTH
ATLANTIC. THIS IS CONSISTENT WITH A POLAR SURFACE HIGH EXTENDING
FROM CENTRAL/NORTHERN ARGENTINA ALONG PATAGONIA INTO TIERRA DEL
FUEGO AND THE DRAKE PASSAGE...INCLUDING FAIR WEATHER CONDITIONS IN
THESE REGIONS ON FRIDAY. TO THE EAST...AS COLD SOUTHWESTERLY WINDS
ARE STILL EXPECTED ALIONG THE COAST OF ARGENTINA ALTHOUGH
PRECIPITATION IS EXPECTED TO BE LIGHT AND ISOLATED. ALSO ON
FRIDAY...A SYSTEM IN THE WESTERLIES IS FORECAST TO ARRIVE INTO
SOUTHERN CHILE IN LOS LAGOS AND AYSEN. MOISTURE CONVERGENCE WILL
FAVOR 05-10MM/DAY AND MAXIMA OF 15-30MM WITH THE RISK OF MOUNTAIN
SNOW. ACCUMULATIONS DECREASE THEREAFTER.

ANOTHER REGION OF INTEREST ARE CENTRAL PORTIONS OF THE
CONTINENT...AS A FRONT IS EXPECTED TO MEANDER AND UPPER JET
DYNAMICS ARE TO FAVOR PRECIPITATION IN THE COOL PORTION OF THE
FRONT. ON FRIDAY...THE FRONT IS EXPECTED ACROSS SOUTHERN SAO
PAULO-BRASIL INTO A LOW LOCATED IN SOUTHERN MATO GROSSO DO
SUL...SOUTHEAST BOLIVIA...SANTA CRUZ DE LA SIERRA. POST-FRONTAL
PRECIPITATION IS EXPECTED IN NORTHERN RIO GRANDE DO SUL/SANTA
CATARINA WHERE EXPECT MAXIMA OF 15-30MM AND LIGHTER AMOUNTS IN
AREAS NORTHWEST. ON SATURDAY...AN UPPER TROUGH AND DIVERGENT
ENTRANCE OF AN UPPER JET WILL FAVOR CYCLOGENESIS OVER SANTA
CATARINA/SOUTHERN PARANA IN BRASIL. THIS WILL INCREASE THE
RESIDENCE TIME OF CONVECTIVE CELLS...FAVORING AN INCREASE IN
24-HOUR RAINFALL TOTALS TO 15-20MM/DAY AND MAXIMA OF 30-60MM
EXTENDING FROM MISIONES-ARGENTINA INTO SANTA CATARINA IN BRASIL.
IN CENTRAL/SOUTHEAST PARAGUAY EXPECT MAXIMA OF 15-30MM. ON
SUNDAY...EXPECT THE HEAVIEST PRECIPITATION TO CLUSTER IN SOUTHEAST
PARANA AND EASTERN SANTA CATARINA WHERE EXPECT MAXIMA OF 25-50MM.
UNDER THE INFLUENCE OF FAVORABLE UPPER JET DYNAMICS...EXPECT
ISOLATED STRONG/HEAVY THUNDERSTORMS.

IN TROPICAL SOUTH AMERICA...MOIST PLUMES IN THE TRADES ARE
ARRIVING INTO NORTHEAST BRASIL. THROUGH EARLY SATURDAY THIS WILL
FAVOR AN INCREASE IN PRECIPITATION TO SUSTAIN MAXIMA OF 15-30MM
FROM SERGIME NORTH INTO RIO GRANDE DO NORTE. THIS PEAKS ON
SATURDAY THROUGH EARLY SUNDAY TO FAVOR MAXIMA OF
20-40MM...DECREASING AFTER.

NORTH OVER THE CONTINENT...MOST ACTIVITY IS EXPECTED WITH WAVES
PROPAGATING IN THE TRADES. THE HIGHER AMOUNTS ARE EXPECTED IN
COLOMBIA/VENEZUELA AND FAR NORTHWEST BRASIL WHERE EXPECT MAXIMA OF
20-45MM/DAY THROUGH EARLY SUNDAY...DECREASING THEREAFTER.

GALVEZ..(WPC)
PALAVECINO (SMN-ARGENTINA)
SARABIA (DMC-CHILE)