868
FXSA20 KWBC 252017
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
316 PM EST WED FEB 25 2026
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/DATA/NCCF/COM/GFS/PROD/
FORECAST BULLETIN 25 FEBRUARY 2026 AT 2000 UTC:
LOW-LEVEL MOISTURE CONVERGENCE AND AN UPPER-LEVEL DIVERGENCE WILL
CONTINUE TO BRING PRECIPITATION OVER THE PACIFIC COAST OF ECUADOR
AND NORTHWESTERN PERU TODAY THROUGH THURSDAY WITH TOTALS RANGING
FROM 20-40MM. OVER THE NORTHERN PERUVIAN ANDES IN PERU, A MAXIMUM
PRECIPITATION OF 30MM IS ANTICIPATED FROM TODAY THROUGH THURSDAY.
VARIOUS FACTORS WILL CONTRIBUTE TO THE DEVELOPMENT OF CONVECTIVE
ACTIVITY IN THE AREA, INCLUDING UPPER-LEVEL DIFFLUENCE, AND THE
PRESENCE OF A SHORTWAVE TROUGH AT MID-LEVELS. AT LOW-LEVELS, DEEP
MOISTURE AND A TROUGH WILL PROVIDE ENOUGH INSTABILITY TO PRODUCE
RAINFALL. UPPER-LEVEL DIVERGENCE, AND LOW-LEVEL MOISTURE
CONVERGENCE WILL ENHANCE RAINFALL ACTIVITY OVER THE WESTERN AMAZON
BASIN, PARTICULAR OVER PERU AND BRAZIL. PRECIPITATION IS ALSO
EXPECTED TODAY THROUGH THURSDAY OVER SOUTHERN SELVA ALTA WITH
MID-LEVEL TROUGHING IN THE REGION.
OVER BOLIVIA, AN UPPER-LEVEL TROUGH IS EXPECTED TO CONTINUE
PROVIDING UPPER-LEVEL SUPPORT FOR THE DEVELOPMENT OF CONVECTIVE
ACTIVITY IN THE AREA TODAY THROUGH THURSDAY. MID-LEVEL TROUGHING,
DEEP MOISTURE AND THE CONVERGENCE OF LOW-LEVEL WINDS WILL BRING
RAINFALL OVER THE SOUTHWEST AMAZON REGION IN BOLIVIA. MAXIMA
PRECIPITATION IS EXPECTED TO HAPPEN OVER THE YUNGAS REGION, WHERE
A LOW-LEVEL TROUGH WILL INCREASE LOW-LEVEL MOISTURE CONVERGENCE.
ACCUMULATIONS ARE EXPECTED TO RANGE BETWEEN 50-100MM STARTING
TODAY THROUGH THURSDAY MORNING.
HEAVY PRECIPITATION AND CONVECTIVE ACTIVITY IS EXPECTED OVER THE
AMAZON DELTA, INTERIOR NORDESTE INTO BAHIA REGION DUE TO THE
PRESENCE OF DEEP MOISTURE AND THE CONVERGENCE OF LOW-LEVEL WINDS.
UPPER-LEVEL SUPPORT IS ALSO ANTICIPATED IN THIS AREA WITH
DIVERGENCE ALONG THE PERIPHERY OF AN UPPER-LEVEL HIGH LOCATED OVER
CENTRAL-WEST BRAZIL. RAINFALL IS ALSO EXPECTED TODAY THROUGH
THURSDAY OVER CENTRAL BRAZIL, PARANA BASIN AND SERRA DO MAR AS A
LOW-LEVEL TROUGH CONTINUES OVER THE REGION ENHANCING DIVERGENCE
AND A FRONTAL BOUNDARY APPROACHES INCREASING INSTABILITY. HEAVY
PRECIPITATION IS EXPECTED TO CONTINUE FROM THURSDAY THROUGH FRIDAY
OVER SERRA DO MAR, ESPIRITO SANTO AND CENTRAL BRAZIL AS A
LOW-LEVEL TROUGH CONTINUES ENHANCING LOW-LEVEL CONVERGENCE AND THE
FRONTAL BOUNDARY PROPAGATES SLOWLY. MID-LEVEL TROUGHS WILL PROVIDE
MORE SUPPORT FOR THUNDERSTORMS AND CONVECTIVE ACTIVITY. TOTALS ARE
ANTICIPATED TO EXCEED 50MM OVER RIO DE JANEIRO AND ESPIRITO SANTO
AND CENTRAL BRAZIL. FROM THURSDAY THROUGH FRIDAY, LOW-LEVEL
MOISTURE CONVERGENCE IS ANTICIPATED TO INCREASE OVER THE CENTRAL
AMAZON BASIN, AND THE EASTERN AMAZON BASIN IN BRAZIL. THIS WILL
INCREASE THE RAINFALL AND THUNDERSTORMS ACTIVITY AS UPPER-LEVEL
DIFFLUENCE PERSISTS IN THE AREA AND DIURNAL HEATING WILL FURTHER
SUPPORT THE DEVELOPMENT OF CONVECTIVE ACTIVITY. MOST OF NORTHERN
BRAZIL, HOWEVER, IS ANTICIPATED TO RECEIVE LOWER PRECIPITATION
TOTALS WITH THE ADVECTION OF DRY AIR AND THE PRESENCE OF LOW-LEVEL
JETS. FROM FRIDAY THROUGH SATURDAY, A STRONG MID-LEVEL TROUGH
REFLECTED AT LOWER LEVELS OVER THE RIO DE JANEIRO AND MINAS GERAIS
IN BRAZIL WILL INCREASE INSTABILITY IN THE REGION. WITH HIGH
PRECIPITABLE WATER AVAILABILITY AND UPPER-LEVEL DIVERGENCE EXPECT
HEAVY PRECIPITATION AND THUNDERSTORMS IN THE AREA. THE LOW-LEVEL
MOISTURE CONVERGENCE ENHANCED BY THE TROUGH WILL EXTEND INTO
CENTRAL BRAZIL, MATO GROSSO AND TOCANTINS, WHICH WILL SUPPORT
THUNDERSTORMS IN THE AREA.
THE PRESENCE OF A LOW-LEVEL TROUGH, LOW-LEVEL MOISTURE ADVECTION,
STRONG UPPER-LEVEL FLOW, AND MID-LEVEL SHORTWAVE TROUGHS ARE
ANTICIPATED TO BRING SOME PRECIPITATION OVER THE CHACO, AND
CORDOBA REGION IN ARGENTINA, PARTICULARLY FROM THURSDAY THROUGH
FRIDAY. AN UPPER-LEVEL TROUGH IS EXPECTED TO INCREASE DIVERGENCE
OVER THE CORDOBA AND LA PAMPA REGION FROM FRIDAY NIGHT THROUGH
SATURDAY MORNING, AND A SLIGHT RISK FOR SEVERE WEATHER IS
ANTICIPATED.
A PLUME OF MOISTURE, ASSOCIATED WITH AN ATMOSPHERIC RIVER, IS
EXPECTED TO REACH SOUTHERN AND CENTRAL CHILE BY THURSDAY. THIS
WILL INCREASE THE PRECIPITATION IN THE AREA, PARTICULARLY FROM
LATE THURSDAY THROUGH SATURDAY. WITH A FRONTAL BOUNDARY AT
LOW-LEVELS, AN UPPER-LEVEL JET, AND A MID-LEVEL TROUGH APPROACHING
THE REGION ON FRIDAY, THERE IS ENOUGH SUPPORT FOR THE DEVELOPMENT
OF RAINFALL IN THE AREA. A SLIGHT RISK FOR SEVERE WEATHER EXISTS
FOR FRIDAY AFTERNOON.
RIVERA-TORRES...(WPC)
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