THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


SOUTH AMERICAN SYNOPSIS




SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
926 AM EDT MON APR 24 2017

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

SYNOPSIS (VALID FROM APRIL 24 AT 0000 UTC): THE 200 HPA ANALYSIS
SHOWS A CELL OF THE SUBTROPICAL RIDGE ENVELOPING CONTINENTAL AREA
TO THE NORTH OF 20S WHILE ANCHORING ON A CLOSED HIGH AT 10S 60W.
THE RIDGE IS VENTING DIURNAL CONVECTION OVER THE CONTINENT TO THE
NORTH OF 13S...WITH MOST ACTIVE CLUSTERING ALONG THE NORTH COAST
OF BRASIL-AMAPA-PARA-AMAZONAS AND RORAIMA...AS WELL AS ACROSS THE
PERUVIAN JUNGLE/NORTHERN BOLIVIA AND MOST OF ECUADOR.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH ENTRANCE AT
45S 56W...THEN ALONG 42S 40W...46S 29W...50S 19W...AND 57S 07W.
THE NORTHERN POLAR LIES ALONG 40S 126W...A 178KT MAXIMUM AT 45S
122W...49S 117W...A 152KT MAXIMUM AT 50S 110W...48S 99W...44S
90W...EXITING AT 43S 78W. IT REFORMS AT 39S 61W...THEN ALONG A
126KT MAXIMUM AT 40S 50W...40S 41W...EXITING AT 41S 31W. THE
SUBTROPICAL JET LIES ALONG A 172KT MAXIMUM AT 41S 120W...45S
112W...44S 100W...41S 89W...EXITING AT 38S 79W. IT REFORMS AT 31S
70W...THEN ALONG 33S 61W...34S 47W...32S 35W...35S 27W...EXITING
AT 43S 14W. A BRANCH TO THE NORTH HAS ITS ENTRANCE AT 28S
78W...THEN ALONG 28S 69W...29S 61W...30S 53W...EXITING AT 29S 44W.

AT 500 HPA A LONG WAVE RIDGE EXTENDS FROM 31S 105W...ALONG 50S
105W...TO 60S 110W. THIS IS INDUCING THE NORTHWARD AMPLIFICATION
OF A SHORT WAVE TROUGH ALONG A CLOSED LOW NEAR 57S 82W...45S
90W...TO 40S 93W. AS IT PUSHES TOWARDS THE SOUTHERN CONE THE
LATTER IS PHASING WITH A SHORT WAVE TROUGH OVER CENTRAL
CHILE/ARGENTINA. FARTHER EAST...BROAD TROUGH DOMINATES THE FLOW
OVER THE SOUTH ATLANTIC...ENVELOPING AREA BETWEEN 50W-00W AND
SOUTH OF 35S.

AT LOW LEVELS...A RIDGE ON THE NORTHERN STREAM OVER THE EASTERN
PACIFIC CENTERS ON A 1029 HPA HIGH AT 36S 102W. SOUTH OF THIS
AXIS...BROAD TROUGH EXTENDS OVER THE SOUTHEAST PACIFIC/SOUTHERN
CONE OF SOUTH AMERICA...WHILE CENTERING ON AN OCCLUDED 994 HPA LOW
AT 56S 83W. IT EXTENDS A FRONT FROM A 994 HPA LOW AT 50S 79W...A
998 HPA LOW AT 52S 74W...48S 69W...45S 73W...A 1006 HPA LOW AT 44S
78W...41S 77W...37S 84W...37S 90W...A 1022 HPA LOW AT 40S
92W...AND 39S 96W. THIS SUSTAINS SCATTERED RAINFALL ACROSS
SOUTHERN CHILE. AN OCCLUDED 994 HPA LOW AT 47S 37W EXTENDS A FRONT
ALONG A 1002 HPA LOW AT 49S 35W...45S 32W...39S 36W...37S
45W...36S 52W...A 1014 HPA LOW AT 36S 59W...33S 64W...31S 70W...TO
A 1020 HPA LOW AT 29S 79W. THIS FAVORS SCATTERED CONVECTION ACROSS
THE BUENOS AIRES PROVINCE. A RIDGE TO THE SOUTH CENTERS ON A 1019
HPA HIGH AT 48S 55W...WHILE ONE TO THE NORTH CENTERS ON A 1021 HPA
HIGH AT 31S 43W. AN OLD FRONT TO THE NORTH LIES ALONG A 1014 HPA
LOW AT 29S 31W...24S 33W...19S 38W... ESPIRITO SANTO/SOUTHERN
MINAS GERAIS TO MATO GROSSO. THIS TRIGGERED ISOLATED DEEP
CONVECTION OVER MINAS GERAIS/ESPIRITO SANTO.

ABDEMUR...FAA (ARGENTINA)
ESPINOLA...DNM (PARAGUAY)
DAVISON/GALVEZ...WPC (USA)




Last Updated: 926 AM EDT MON APR 24 2017