301
FXSA20 KWBC 171859
PMDSA
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
159 PM EST TUE FEB 17 2026
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/DATA/NCCF/COM/GFS/PROD/
FORECAST BULLETIN 17 FEBRUARY 2026 AT 1900 UTC:
IN THE HIGH MID-LATITUDES...
ON MONDAY MORNING, THE AXIS OF A MID-TO-UPPER LEVEL SHORTWAVE
TROUGH WILL BE PROPAGATING ACROSS SOUTHERN AND AUSTRAL CHILE. AT
THE SURFACE, A DECAYING OCCLUDED FRONT WILL BE MOVING INLAND AND
THERE WILL BE AN INCREASE IN MOISTURE CONVERGENCE ACROSS SOUTHERN
CHILE. MEANWHILE, THE AFFILIATED COLD FRONT WILL BE MOVING ACROSS
CENTRAL CHILE. THIS FRONT WILL BE ACCOMPANIED BY A LONG FETCH
MOISTURE PLUME THAT IS ANTICIPATED TO DECAY BY EARLY WEDNESDAY
MORNING. ALSO, FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT,
EXPECT NORTHWEST TO WESTERLY LOW LEVEL WINDS ACROSS THIS REGION.
THIS WIND PATTERN WILL ENHANCE MOISTURE CONVERGENCE. MODERATE
RAINFALL ACCUMULATIONS ARE EXPECTED ACROSS THE TWO AFOREMENTIONED
REGIONS ON TUESDAY. BY WEDNESDAY NIGHT, A JET STREAK MAX WILL BE
MOVING INTO THE CONTINENT AND IT WILL SUSTAIN UPPER DIVERGENCE
ACROSS SOUTHERN AND AUSTRAL CHILE. A SURFACE FRONTAL SYSTEM WILL
BE PRESENT AT THE SURFACE AND IT WILL BE ACCOMPANIED WITH A
LONG-FETCH MOISTURE PLUME AS WELL. THIS FRONTAL SYSTEM IS
ANTICIPATED TO MOVE INLAND STARTING LATE WEDNESDAY AFTERNOON. LOW
LEVEL WINDS WILL BE EXCEEDING 40 KNOTS THROUGH MID-DAY THURSDAY,
FURTHER ENHANCING LOW LEVEL MOISTURE CONVERGENCE AND OROGRAPHIC
LIFT. ON THURSDAY, STILL EXPECT ONSHORE FLOW INTO NORTHERN AUSTRAL
CHILE WITH PRECIPITABLE WATER VALUES EXCEEDING 30MM THROUGH FRIDAY
MORNING. THUS, ELEVATED DAILY TOTAL RAINFALL MAXIMA ARE
ANTICIPATED FOR THURSDAY AND FRIDAY ACROSS THE NORTHERN REGIONS OF
AUSTRAL CHILE.
IN THE LOWER MID-LATITUDES...
AN UPPER JET STREAK MAX WILL BE INTENSIFYING STARTING WEDNESDAY
THROUGH EARLY THURSDAY MORNING AND IT WILL CONTINUE TO DRIVE THE
DYNAMIC REGIME ACROSS NORTH-CENTRAL ARGENTINA AND URUGUAY. THERE
WILL BE A ZONAL UPPER LEVEL WIND PATTERN AS WELL FOR THIS PERIOD.
MEANWHILE AT THE LOW LEVELS, EXPECT A TROUGH TO GAIN DEFINITION ON
TUESDAY NIGHT FROM THE SOUTHERN CHACO REGION INTO THE MESOPOTAMIA
REGION IN ARGENTINA. MOISTURE POOLING WILL PERSISTENT ACROSS THIS
BOUNDARY AND IT WILL LEAD TO PRECIPITABLE WATER VALUES EXCEEDING
38MM. THIS TROUGH WILL REMAIN IN THE REGION THROUGH THURSDAY.
THEREAFTER, EXPECT THE LOW LEVEL TROUGH TO BEGIN MOVING NORTHWARD
INTO FAR NORTHERN ARGENTINA AND LOSING ITS STRUCTURE THEREAFTER IN
RESPONSE TO THE EASTWARD PROPAGATION OF AN UPPER LEVEL TROUGH INTO
THE REGION. THE PRESENCE AND PROPAGATION OF THE UPPER TROUGH WILL
LEAD TO THE WEAKENING OF THE UPPER JET STREAK MAX. WITH RESPECT TO
RAINFALL, MODERATE ACCUMULATIONS ARE LIKELY FROM TUESDAY MORNING
THROUGH WEDNESDAY MORNING ACROSS CORDOBA AND WESTERN LA
PAMPA-BUENOS AIRES. FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING, THE HIGHEST ACCUMULATIONS WILL OCCUR ACROSS CORDOBA,
SANTA FE, AND THE MESOPOTAMIA REGIONS OF ARGENTINA. MODERATE TOTAL
PRECIPITATION MAXIMA IS STILL LIKELY ACROSS THE MESOPOTAMIA AND
NORTHWEST ARGENTINA REGIONS FROM THURSDAY MORNING THROUGH FRIDAY
MORNING.
IN THE SUBTROPICS...
A FEATURE OF INTEREST IS A FRONTAL SYSTEM THAT IS OCCLUDING OFF
THE COAST OF RIO DE LA PLATA. A COLD FRONT WILL EXTEND INTO
SOUTHEASTERN BRASIL DURING THE DAY ON THURSDAY. BY WEDNESDAY
NIGHT, THIS FRONT WILL BE LOCATED NEAR THE STATES OF CATARINA AND
SAO PAULO. ON FRIDAY NIGHT, THE COLD FRONT WILL EXTEND INTO SAO
PAULO AND RIO DE JANEIRO. THE MOST SIGNIFICANT MOISTURE POOLING
AND MOISTURE CONVERGENCE WILL BE IN THE VICINITY OF THIS FRONTAL
SYSTEM. AT THE SAME TIME, EXPECT THE STRENGTHENING OF THE BOLIVIAN
HIGH, A SUBTROPICAL UPPER LEVEL RIDGE, AND MID-LEVEL DIFFLUENCE.
THE PRESENCE OF THE UPPER RIDGE WILL SUPPORT UPPER DIVERGENCE
ACROSS SOUTHEASTERN BRASIL FOR THE NEXT THREE DAYS. WITH RESPECT
TO PRECIPITATION ACCUMULATIONS ASSOCIATED WITH THIS FRONTAL
SYSTEM, EXPECT MODERATE TO HEAVY TOTAL PRECIPITATION MAXIMA. THE
AREA WITH THE GREATEST PRECIPITATION IMPACTS WILL ALSO SHIFT
NORTHEASTWARD WITH PASSING DAYS. FROM TUESDAY MORNING THROUGH
WEDNESDAY MORNING, THE AREA WITH GREATEST IMPACT WILL BE CONFINED
TO THE SOUTH REGIONS OF BRASIL. BY WEDNESDAY MORNING THROUGH
THURSDAY MORNING, THE HIGHEST ACCUMULATIONS WILL BE LOCATED ACROSS
MINAS GERAIS AND SAO PAULO. FROM THURSDAY MORNING THROUGH FRIDAY
MORNING, THE AREA WITH THE GREATEST PRECIPITATION IMPACTS WILL BE
RIO DE JANEIRO AND MINAS GERAIS.
ELSEWHERE, THROUGH WEDNESDAY MORNING, THERE WILL BE A SIGNIFICANT
INCREASE IN PRECIPITABLE WATER ACROSS THE AMAZON DELTA AND THE
BRAZILIAN NORTH COAST DUE TO THE PRESENCE OF THE INTERTROPICAL
CONVERGENCE ZONE AND THE NEAR EQUATORIAL TROUGH (NET). THERE WILL
BE A PRESENCE OF UPPER DIVERGENCE IN THIS REGION AS WELL THAT WILL
ASSIST IN THE UPWARD DEVELOPMENT OF CONVECTION. THESE CONDITIONS
WILL FAVOR ENHANCED PRECIPITATION ACCUMULATIONS FROM TUESDAY
MORNING THROUGH WEDNESDAY MORNING. THEREAFTER, EASTERLY TO
NORTHEASTERLY LOW LEVEL WINDS WILL PERSIST ACROSS THE REST OF THE
AMAZON BASIN, WHICH WILL HELP IN KEEPING THE REGION MOIST.
IN SOUTHEASTERN PERU, AN INVERTED UPPER LEVEL TROUGH WILL BE
PRESENT IN THE REGION THROUGH WEDNESDAY MORNING WHICH WILL SUPPORT
UPPER DIVERGENCE ACROSS THE SELVA ALTA AND THE SOUTHWEST AMAZON.
THERE WILL ALSO BE MID-LEVEL SHORTWAVE TROUGHS TRAVERSING THE
REGION FOR THIS PERIOD. THUS, EXPECT ENHANCED TOTAL PRECIPITATION
MAXIMA FOR TUESDAY AND DECREASING IN MAGNITUDE THEREAFTER.
MEANWHILE, ACROSS THE NORTHWEST AND CENTRAL AMAZON BASIN, AN UPPER
LEVEL DIFFLUENT PATTERN WILL BE PRESENT ACROSS THIS REGION THROUGH
THURSDAY MORNING AND IT WILL PROMOTE UPPER DIVERGENCE. DAILY
RAINFALL ACCUMULATIONS ARE EXPECTED TO BE THE MOST INTENSE ON
TUESDAY AND DECREASING THEREAFTER AS WELL.
IN THE PACIFIC COASTS OF COLOMBIA AND ECUADOR, THERE WILL BE A
CHANGE IN THE LOW LEVEL WINDS STARTING WEDNESDAY, WHERE THE
DIRECTION WILL BE FROM THE WEST. THIS PATTERN WILL PROMOTE
OROGRAPHIC ENHANCEMENT AND MOISTURE CONVERGENCE THAT WILL LEAD TO
MODERATE TO HEAVY TOTAL PRECIPITATION MAXIMA FOR TUESDAY AND
WEDNESDAY. NOTE THAT MID-LEVEL WIND SPEEDS WILL INCREASE SLIGHTLY
AFTER THURSDAY ACROSS SOUTHERN PERU, WHICH MAY INCREASING SPEED
SHEAR IN THE REGION.
TINOCO-MORALES...(WPC)
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