076  
FXSA20 KWBC 102031  
PMDSA  
 
SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
331 PM EST MON FEB 10 2025  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/DATA/NCCF/COM/GFS/PROD/  
 
SOUTH AMERICAN FORECAST BULLETIN FOR 10 FEB 2025 AT 2030 UTC:  
 
IN THE CLIMATE SCALE, THE MADDEN-JULLIAN OSCILLATION PHASE WILL  
BECOME MORE DIVERGENT BEGINNING THIS WEEK THROUGH THE END OF THE  
WEEK. THIS WILL FAVOR MORE WIDESPREAD RAINFALL WHERE CONDITIONS  
ARE FAVORABLE FOR DEVELOPMENT.  
 
IN MID-LATITUDE SOUTH AMERICA...  
 
IN THE UPPER LEVELS, A POSITIVELY TITLED UPPER TROUGH WILL HELP  
INDUCE A CUT-OFF UPPER HIGH BY MID-DAY TUESDAY AROUND 99S51W AND  
IS EXPECTED TO BE OVER AUSTRAL CHILE BY WEDNESDAY EVENING. THIS  
PATTERN WILL YIELD TO THE ACCELERATION OF THE UPPER WINDS TO THE  
SOUTH AND WILL ENHANCE A PRE-EXISTING JET STREAK AFTER WEDNESDAY  
EVENING. IN ADDITION, A MID-LEVEL SHORTWAVE TROUGH, ACCOMPANIED  
VORTICITY ADVECTION, AND LOW LEVEL MOISTURE PLUME WILL YIELD TO  
MAXIMUM RAINFALL TOTALS OF 15-20MM FOR TUESDAY MORNING THROUGH  
WEDNESDAY MORNING AND TOTALS OF 20-35MM FOR WEDNESDAY MORNING  
THROUGH THURSDAY MORNING.  
 
IN NORTHERN ARGENTINA AND URUGUAY, A COLD FRONT IS CURRENTLY  
LOCATED ACROSS LA PAMPA AND BUENOS AIRES STATES AND WILL CONTINUE  
TO PROPAGATE NORTHWARDS. BY MONDAY EVENING, IT WILL BE LOCATED  
ACROSS CENTRAL ARGENTINA. BY TUESDAY EVENING, EXPECT THE FRONT TO  
BE ACROSS NORTHERN URUGUAY THROUGH NORTHWEST ARGENTINA. BY  
WEDNESDAY EVENING, THE FRONT WILL BE ACROSS NORTHERN ARGENTINA AND  
SOUTHERN BRASIL. A COMBINATION OF MID-LEVEL SHORTWAVE TROUGHS AND  
INCREASING MOISTURE CONVERGENCE WILL YIELD TO MAXIMUM RAINFALL  
TOTALS OF 30-60MM FOR TUESDAY MORNING THROUGH WEDNESDAY MORNING  
AND TOTALS OF 25 - 50MM FOR WEDNESDAY MORNING THROUGH THURSDAY  
MORNING.  
 
IN TROPICAL SOUTH AMERICA...  
 
IN THE UPPER LEVELS, THE BOLIVIAN HIGH IS CURRENTLY LOCATED OFF  
THE COAST OF CENTRAL CHILE. BY WEDNESDAY, IT WILL BEGIN  
RESTRUCTURING OVER NORTHERN CHILE AND SOUTHWEST BOLIVIA. ANOTHER  
FEATURE OF INTEREST IS AN UPPER CUT OFF LOW OVER SOUTH-CENTRAL  
BRASIL ON MONDAY AFTERNOON, WHICH IS EXPECTED TO MEANDER ACROSS  
THE REGION THROUGH THE NEXT THREE DAYS. THESE FEATURES WILL HELP  
ENHANCE UPPER LEVEL DIFFLUENCE AND DIVERGENCE ACROSS THIS REGION.  
ONE OF THE AREAS OF INTEREST IS THE WESTERN AMAZON BASIN, WHERE  
FAVORABLE MOISTURE CONVERGENCE AND UPPER LEVEL DYNAMICS WILL  
ASSIST IN ENHANCING RAINFALL TOTALS. ENHANCED UPPER LEVEL  
DIVERGENCE, LIMITED SHEAR, AND THE PROXIMITY TO THE NEAR  
EQUATORIAL JET (NET) WILL YIELD TO MAXIMUM RAINFALL TOTALS OF 30 -  
60MM THROUGH TUESDAY MORNING, 35 - 75MM FOR TUESDAY MORNING  
THROUGH WEDNESDAY MORNING, AND 30 - 60MM FOR WEDNESDAY MORNING  
THROUGH THURSDAY MORNING.  
 
IN ECUADOR, HEAVY PRECIPITATION IS ANTICIPATED DAILY THROUGH THE  
NEXT THREE DAYS. IN THE LOW-LEVELS, MOISTURE CONVERGENCE WILL BE  
MOST FAVORABLE TODAY THROUGH TUESDAY MORNING AS NORTHWEST FLOW  
CONTINUES TO AFFECT THE REGION. THOUGH THE WIND SPEEDS REMAIN LOW,  
LONG FETCH MOISTURE WILL CONTINUE TO BE DRIVEN INTO THE COAST OF  
ECUADOR THROUGH THURSDAY MORNING. ADDITIONALLY, WEAK MID-LEVEL  
WIND SPEEDS AND UPPER LEVEL DIVERGENCE ASSOCIATED WITH A  
SEMI-STATIONARY TROUGH, WITH AN AXIS ACROSS 04S 81W TO 17S 96W,  
WILL ENHANCE THE POTENTIAL FOR HIGHER RAINFALL TOTALS THROUGH THE  
FORECAST CYCLE. EXPECT THE HIGHEST MAXIMUM RAINFALL TOTALS TO  
OCCUR TODAY THROUGH TUESDAY MORNING, WITH TOTALS OF 30 - 60MM AND  
DECREASING FOR TUESDAY MORNING INTO WEDNESDAY MORNING. BY  
WEDNESDAY MORNING THROUGH THURSDAY MORNING, AN INCREASE IN UPPER  
LEVEL EASTERLIES WILL YIELD TO AN INCREASE IN MAXIMUM RAINFALL  
TOTALS, WHICH ARE EXPECTED TO BE 30 - 60MM.  
 
IN NORTHERN SOUTH AMERICA, A SERIES OF LOW LEVEL TROUGHS, THE  
INTERTROPICAL CONVERGENCE ZONE (ITCZ), AND THE NET WILL BE THE  
MAIN DRIVING FORCE FOR PRECIPITATION THROUGH THE NEXT THREE DAYS.  
NOTE, A SECONDARY ITCZ WILL FORM OVER THE ATLANTIC BASIN AFTER  
TUESDAY MORNING AND WILL INFLUENCE PRECIPITATION PATTERNS IN THE  
AMAZON DELTA AND THE BRASILIAN NORTH COAST.  
 
MORALES...(WPC)  
CASTELLANOS...(WPC)  
 
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