Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
 
South American Forecast Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1809Z Oct 27, 2014)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product


SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
209 PM EDT MON OCT 27 2014

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

MODEL DISCUSSION (VALID FROM OCTOBER 27 AT 00UTC): GLOBAL MODELS
AND ENSEMBLE MEMBERS CONTINUE IN EXCELLENT AGREEMENT REGARDING
FORECAST EVOLUTION. FORECAST CONFIDENCE IS HIGH.

UPPER TROUGH HAS ORGANIZED OVER SOUTHEASTERN BRASIL...AND IS
VENTILATING CONVECTION ACROSS PARTS OF ESPIRITO SANTO AND MINAS
GERAIS. EXPECTING ACTIVE CONVECTION TO PRODUCE LARGEST AMOUNTS
ACROSS ESPIRITO SANTO AND EASTERN MINAS GERAIS WITH MAXIMA OF
30-60MM/DAY THROUGH TUESDAY MORNING...AND 35-70MM/DAY BY TUESDAY
INTO WEDNESDAY MORNING. AMOUNTS ARE TO DECREASE AFTERWARDS.

OTHER REGION OF INTEREST WILL BE CENTRAL ARGENTINA. SEVERAL SHORT
WAVE TROUGHS ARE TO CROSS THE ANDES AND INTERACT WITH MOIST AND
UNSTABLE AIR MASS ACROSS CENTRAL PORTIONS OF ARGENTINA. A SHORT
WAVE VORTEX IS RAPIDLY CROSSING THE REGION TODAY. THIS WILL
INTERACT WITH SURFACE FRONT TO CONTINUE ENHANCING THUNDERSTORMS
AND PRECIPITATION BETWEEN VIEDMA AND MOST OF THE SOUTHERN BUENOS
AIRES PROVINCE...WHERE EXPECTING MAXIMA OF 25-50MM/DAY. FURTHER
NORTH...SCATTERED THUNDERSTORMS ALONG FRONTAL BOUNDARY ARE TO
PRODUCE MAXIMA OF 15-30MM/DAY THROUGH EARLY TUESDAY. NEW AND
LARGER UPPER TROUGH IS TO CROSS THE ANDES ON TUESDAY. THIS TROUGH
WILL INTERACT WITH LINGERING STATIONARY BOUNDARY ACROSS THE
CENTRAL BUENOS AIRES PROVINCE AND MOIST AIR MASS IN THE REGION TO
SUSTAIN STRONG CONVECTION. EXPECTING AFTERNOON THUNDERSTORMS
INTENSIFYING OVER THE EVENING/OVERNIGHT HOURS AND PRODUCING MAXIMA
OF 40-80MM/DAY THROUGH EARLY WEDNESDAY. CONVECTION WILL REACTIVATE
DURING THE DAY ON WEDNESDAY...WITH MODELS SHOWING STRONG
INSTABILITY DEVELOPING IN THE SOUTHERN CHACO INTO THE MESOPOTAMIA
REGION. THUS EXPECTING SEVERE THUNDERSTORMS TO CONTINUE DEVELOPING
WITH LARGEST AMOUNTS FROM ENTRE RIOS/CORRIENTES INTO
URUGUAY/WESTERN RIO GRANDE DO SUL...WITH MAXIMA OF 50-100MM/DAY.
ISOLATED HIGHER AMOUNTS ARE EXPECTED IN STRONGEST THUNDERSTORMS.
FURTHER INLAND EXPECTING MAXIMA OF 20-35MM/DAY IN PARTS OF
CORDOBA/SANTA FE AND SANTIAGO DEL ESTERO INTO EARLY THURSDAY.
DURING THURSDAY INTO FRIDAY...STRONGEST CONVECTION WILL
CONCENTRATE ACROSS THE UPPER MESOPOTAMIA REGION TO PRODUCE MAXIMA
OF 25-50MM/DAY FROM SOUTHEASTERN PARAGUAY INTO MISIONES AND THE
INTERIOR OF SOUTHERN BRASIL. LATER IN THE CYCLE...AS THE BOLIVIAN
HIGH RESTRUCTURES FROM SOUTHERN PERU INTO SOUTHERN
BOLIVIA...VENTILATION WILL INCREASE IN THE REGION.
FURTHERMORE...AN INTENSIFICATION OF THE CHACO LOW BY THURSDAY INTO
FRIDAY WILL LEAD TO THE ADVECTION OF MOISTURE AND INSTABILITY FROM
SOUTHWESTERN BRASIL INTO THE CHACO PARAGUAYO AND EASTERN BOLIVIA.
THIS PATTERN IS TO INCREASE THE COVERAGE OF THUNDERSTORMS IN THE
REGION WITH SCATTERED MAXIMA OF 20-45MM/DAY.

ACROSS CHILE...LARGEST AMOUNTS ARE EXPECTED BETWEEN TUESDAY AND
EARLY THURSDAY...WHERE ENHANCED CONVECTIVE INSTABILITY BEHIND A
STRONG COLD FRONT WILL LEAD TO MAXIMA OF 10-15MM/DAY FROM
TEMUCO/VALDIVIA TO THE SOUTH INTO THE AYSEN REGION.

CAROCA...DMC (CHILE)
DURAN...SENAHMI (PERU)
GALVEZ...WPC (USA)