Prognostic Meteorological Discussion
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FXSA20 KWBC 071928
PMDSA

SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
327 PM EDT MON OCT 07 2024

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

SOUTH AMERICAN FORECAST BULLETIN FOR 07 OCT 2024 AT 1930 UTC:

A POTENT TROUGH IN THE NORTHERN STREAM IS APPROACHING THE ANDES IN
CENTRAL AND NORTHERN CHILE. THE PRESENCE OF A ROBUST RIDGE TO THE
EAST IS LIMITING THE EASTWARD PROGRESSION OF THIS
SYSTEM...YILENDING TO A SLOW EVOLUTION. THE TROUGH IS LOWERING THE
PRESSURES IN REGIONS EAST OF THE ANDES...WHILE STIMULATING
SNOWFALL IN THE CORDILLERA IN CENTRAL CHILE. FURTHERMORE...A
DEVELOPING CUT OFF LOW IS STIMULATING PRECIPITATION IN PORTIONS OF
THE CUARTA AND QUINTA REGION IN CHILE. ON MONDAY...EXPECT AMOUNTS
OF 05-10MM/DAY AND ISOLATED MAXIMA OF 15-20MM IN THE CUARTA AND
QUINTA REGIONES...WHILE IN THE CORDILELRA EXPECT SNOWFALL AMOUNTS
OF 10-20CM/DAY. ON TUESDAY EXPECT SIMILAR AMOUNTS FROM VALPARAISO
INTO THE CUARTA REGION WHILE IN THE CORDILLERA EXPECT 15-30CM/DAY.
AMOUNTS ARE EXPECTED TO DECREASE THEREAFTER.

EAST OF THE ANDES...A FRONT EXTENDS ACROSS SOUTHERN BRASIL INTO
SOUTH PARAGUAY AND NORTHERN ARGENTINA. LIFT ENHANCED BY THE
APPROACHING UPPER TROUGH IS STIMULATING THE DEVELOPMENT OF
THUNDERSTORMS AND A FEW AREAS OF HEAVY PRECIPITATION. THROUGH
EARLY TUESDAY...EXPECT 15-20MM/DAY AND MAXIMA OF 30-60MM FROM
NORTH-CENTRAL ARGENTINA INTO RIO GRANDE DO SUL IN BRASIL INCLUDING
A SLIGHT RISK OF SEVERITY. IN INTERIOR PORTIONS OF NORTHERN
ARGENTINA EXPECT MAXIMA OF 15-30MM WITH A MARGINAL RISK OF
SEVERITY. IN INTERIOR PORTIONS OF CENTRAL ARGENTINA EXPECT MAXIMA
OF 20-35MM AND A RISK OF HEAVY THUNDESTORMS. ON TUESDAY...ENHANCED
SOUTHEASTERLY WINDS WILL CONTINUE TO ENHANCE MOISTURE CONVERGENCE
IN INTERIOR PORTIONS OF NORTH-CENTRAL ARGENTINA...WHERE EXPECT
MAXIMA OF 30-60MM. IN SANTA CATARINA...NORTHERN RIO GRANDE DO SUL
INTO CENTRAL PARAGUAY AND NORTHEAST ARGENTINA EXPECT MAXIMA OF
20-45MM WITH A MARGINAL RISK FOR SEVERITY. ALONG THE EASTERN
CORDILELRA IN SOUTHERN BOLIVIA AND FAR NORTHERN ARGENTINA EXPECT
10-15MM/DAY AND ISOLATED MAXIMA OF 20-40MM. ON
WEDNESDAY...EXPECTTHE FOCUS FOR THE STRONGEST CONVECTION AND
LARGEST RAINFALL ACCUMULATION TO CLUSTER IN NORTHERN RIO GRANDE DO
SUL AND PARANA IN BRASIL. ECHO TRAINING ALONG A SURFACE FRONT WILL
LIKELY ENHANCE ACCUMULATION. EXPECT 15-30MM/DAY AND MAXIMA OF
40-80MM. IN CENTRAL PARAGUAY AND MATO GROSSO DO SUL IN BRASIL
EXPECT MAXIMA OF 20-45MM...WHILE FRONTAL CONVECTION ACROSS CENTRAL
AND SOUTHEAST BOLIVIA WILL FAVOR MAXIMA OF 20-35MM.

ALSO OF INTEREST...ONSHORE FLOW ALONG A SURFACE FRONT IN SOUTHEAST
BRASIL WILL DEVELOP MODERATE PRECIPITATION IN ESPIRITO SANTO AND
EASTERN RIO DE JANEIRO ON WEDNESDAY...WHERE EXPECT MAXIMA OF
20-40MM.

IN THE SOUTHERN CONE...SEVERAL SURFACE FRONTS ARE EXPECTED TO
FAVOR INTERMITTENT PRECIPITATION...ALTHOUGH MODERATE AMOUNTS ARE
EXPECTED TO REMAIN WEST OF THE ANDES AND OCCUR IN AN ISOLATED
MANNER IN AREAS SOUTH OF 50S. EXPECT THE LARGEST ACCUMULATION TO
DEVELOP ON WEDNESDAY...PRIMARILY IN ASSOCIATION WITH A TIGHTENING
OF THE PRESSURE GRADIENT. THIS WILL FAVOR AMOUTNS OF 10-15MM/DAY
AND MAXIMA OF 20-40MM IN AYSEN AND NORTHERN MAGALLANES.

GALVEZ...(WPC)
$$