485
FXSA20 KWBC 262002
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
302 PM EST THU FEB 26 2026
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/DATA/NCCF/COM/GFS/PROD/
FORECAST BULLETIN 26 FEBRUARY 2026 AT 2000 UTC:
HEAVY RAINFALL AND THUNDERSTORMS ARE EXPECTED TO IMPACT BRAZIL
THROUGHOUT THE FORECAST PERIOD. THIS IS DUE TO DEEP MOISTURE FROM
THE AMAZONIAN REGION BEING ADVECTED TOWARDS EASTERN BRAZIL, AND
LOW-LEVEL WINDS CONVERGING ALONG THE INTERIOR INTO EASTERN BRAZIL,
WITH A LOW-LEVEL TROUGH OVER THE SAO PAULO AND MINAS GERAIS
REGION. FURTHER SUPPORT FOR THE DEVELOPMENT OF THUNDERSTORMS AND
DEEP CONVECTION IS ANTICIPATED WITH THE PRESENCE OF MID-LEVEL
TROUGHS AND UPPER-LEVEL DIVERGENCE ACROSS THE REGION. HEAVY
RAINFALL WILL START OVER THE SERRA DO MAR AS A FRONTAL BOUNDARY
APPROACHES, INCREASING INSTABILITY, AND OVER ESPIRITO SANTO, MINAS
GERAIS, AND INTO THE MATO GROSSO REGION TODAY THROUGH FRIDAY.
ACCUMULATIONS ARE EXPECTED TO BE AROUND 25-50MM OVER SERRA DO MAR,
AND AROUND 50-100MM OVER ESPIRITU SANTO. AS THE LOW-LEVEL TROUGH
PROPAGATES NORTHWARD SLOWLY, PRECIPITATION WILL THEN INCREASE
FURTHER NORTH, IMPACTING MINAS GERAIS, SOUTHERN BAHIA, INTERIOR
NORDESTE, AND TOCANTINS WHERE LOW-LEVEL CONVERGENCE IS ANTICIPATED
TO INCREASE, AND MID-LEVEL TROUGHS WILL DEVELOP. ACCUMULATIONS
ARE EXPECTED TO BE AROUND 50-100MM OVER THE ESPRITO SANTO REGION
FROM FRIDAY THROUGH SATURDAY, AND AROUND 40-80MM OVER THE CENTRAL
BRAZIL REGION. FROM SATURDAY THROUGH SUNDAY, ACCUMULATIONS ARE
EXPECTED TO BE AROUND 40-80MM OVER SOUTHERN BAHIA INTO MINAS
GERAIS, WITH HIGHER ISOLATED TOTALS. DRY AIR WILL PERSIST OVER THE
BRAZILIAN NORDESTE, RESULTING IN A MINIMUM IN PRECIPITATION. A
DRYING TREND IS ALSO EXPECTED OVER SOUTHERN MATO GROSSO, THE
PANTANAL, AND THE BRAZILIAN PARANA BASIN AS DRY AIR IS ADVECTED
FROM FURTHER SOUTH, PARTICULARLY FROM SATURDAY THROUGH SUNDAY.
OTHER REGIONS OF INTEREST ARE THE AMAZON DELTA AND PORTIONS OF THE
BRAZILIAN NORTH COAST AS DEEP MOISTURE FROM THE ATLANTIC IS
ADVECTED INTO THE REGION. TOTALS IN THAT AREA WILL RANGE BETWEEN
20-45MM STARTING TODAY THROUGH SATURDAY, BUT HIGHER TOTALS ARE
ANTICIPATED FROM SATURDAY THROUGH SUNDAY.
OVER ECUADOR, DAILY RAINFALL IS ANTICIPATED DUE TO THE PRESENCE OF
DEEP MOISTURE, DIURNAL HEATING, AND LOCAL EFFECTS. ACCUMULATIONS
ARE EXPECTED TO BE RELATIVELY LOW, RANGING FROM 20-35MM, AS WEAK
LOW-LEVEL WINDS PERSIST THROUGHOUT THE FORECAST PERIOD. IN
PERU,DAILY RAINFALL IS EXPECTED MOSTLY OVER THE SELVA ALTA, WHERE
MOISTURE FROM THE AMAZONIAN REGION OF THE CONTINENT IS BEING
ADVECTED. AT UPPER LEVELS, ANTICYCLONIC FLOW DOMINATES, BUT THE
PRESENCE OF SHORTWAVE MID-LEVEL TROUGHS WILL LIKELY RESULT IN
ISOLATED THUNDERSTORMS.
BOLIVIA IS AN AREA OF INTEREST, PARTICULARLY TOWARDS THE END OF
THE FORECAST PERIOD, AS AN UPPER-LEVEL TROUGH APPROACHES CHILE AND
NORTHWESTERN ARGENTINA, INCREASING UPPER-LEVEL DIVERGENCE OVER
BOLIVIA. A MID-LEVEL SHORTWAVE TROUGH AND HIGH PRECIPITABLE WATER
AVAILABILITY WILL ENHANCE RAINFALL IN THE REGION.
A PLUME OF MOISTURE IS ANTICIPATED TO REACH SOUTHERN TO CENTRAL
CHILE ON FRIDAY, INCREASING PRECIPITATION FOR THE REGION THROUGH
SUNDAY. WITH AN UPPER-LEVEL TROUGH PASSING THROUGH THE REGION ON
FRIDAY AND AN UPPER-LEVEL JET REACHING THE AREA EARLY ON SATURDAY,
INSTABILITY IS ANTICIPATED FROM FRIDAY THROUGH SUNDAY. DAILY
ACCUMULATIONS OF 20-35MM ARE EXPECTED STARTING ON FRIDAY MORNING
THROUGH THE END OF THE FORECAST PERIOD.
RIVERA-TORRES...(WPC)
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