THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


SOUTH AMERICAN SYNOPSIS




SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
947 AM EST FRI JAN 19 2018

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

SYNOPSIS (VALID FROM JAN 19 AT 0000 UTC): THE 200 HPA ANALYSIS
SHOWS THE BOLIVIAN HIGH CENTERS ON A HIGH OVER SOUTHWESTERN
BOLIVIA AND EXTENDS A ZONAL AXIS FROM 20S 100W...ACROSS NORTHERN
CHILE/SOUTHERN BOLIVIA...INTO SAO PAULO-BRASIL. THE HIGH IS
VENTILATING CONVECTION ALONG ITS PERIPHERY...ESPECIALLY ACROSS
MATO GROSSO DO SUL-PARANA-SAO PAULO...WHERE INSTABILITY REMAINS
HIGH...AND OVER THE ALTIPLANO AND PERUVIAN CENTRAL ANDES. THE
CAVADO DO NORDESTE IS ELONGATED AND EXTENDS FROM BAHIA INTO A LOW
IN SOUTHERN PARA. THIS IS VENTILATING CONVECTION ALONG ITS
NORTHERN PERIPHERY IN INTERACTION WITH THE NET...MOSTLY ACROSS
CENTRAL/NORTHERN PARA AND MARANHAO IN BRASIL.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET EXTENDING
ALONG A 124KT MAXIMA AT 60S 120W...EXITING AT 47S 112W. IT REFORMS
AT 50S 108W ALONG 54S 99W...A 152KT MAXIMA AT 59S 87W...A 170KT
MAXIMA AT 59S 73W...EXITING AT 58S 64W. ANOTHER FINGER REFORMS AT
62S 51W EXITING AT 53S 43W. THE NORTHERN POLAR JET EXTENDS ALONG
46S 120W...45S 110W...47S 104W...A 152KT MAXIMA AT 50S 97W...A
152KT MAXIMA AT 56S 81W...51S 63W. IT REFORMS AT 50S 57W EXITING
AT 43S 48W. IT REFORMS AT 42S 42W...ALONG A 137KT MAXIMA AT 46S
33W...EXITING AT 43S 18W. THE SUBTROPICAL JET FORMS AT 39S 116W
ALONG 43S 105W...48S 93W...50S 78W...EXITING AT 43S 69W. ANOTHER
BRANCH FORMS AT 30S 85W ALONG 30S 70W...32S 54W...EXITING AT 36S
41W. IT REFORMS AT 38S 38W ALONG 41S 30W...EXITING AT 39S 20W. THE
SUBEQUATORIAL JET EXTENDS ALONG 01S 108W ALONG 05N 88W.

AT 500 HPA...A LONG WAVE PATTERN IS PRESENT WITH A TROUGH THAT
CENTERS ON A LOW AT 66S 108W AND EXTENDS AN AXIS NORTH ALONG
120W-100W AND TO THE SOUTH OF 38S. TO THE EAST...A RIDGE EXTENDS
ALONG 90W-75W AND FROM 35S SOUTH INTO 48S. A SHORT WAVE TROUGH
EXTENDS FROM CENTRAL ARGENTINA INTO A LOW OFF THE COAST OF CENTRAL
CHILE LOCATED AT 33S 72W. THIS WAS AIDING ISOLATED THUNDERSTORMS
IN CUYO. A LONG WAVE TROUGH EXTENDS TO THE EAST FROM 60S 38W ALONG
43S 45W...INTO EASTERN PARANA-BRASIL. THIS IS AIDING WITH
CONVECTIVE DEVELOPMENT OVER SAO PAULO AND PARANA-BRASIL.

AT LOW LEVELS...A 982 HPA OCCLUDED LOW CENTERS AT 60S 61W AND
EXTENDS A FRONT ALONG A 998 HPA LOW AT 52S 59W...49S 59W...A 1006
HPA LOW AT 45S 65W...NORTHERN PATAGONIA AT 40S 69W...42S 74W...AND
AN ILL-DEFINED BOUNDARY INTO A 1018 HPA LOW AT 45S 78W...43S 86W.
TWO 1027 HIGHS CENTER OVER THE EASTERN PACIFIC AT 32S 99W AND AT
37S 84W. A 1013 HPA HIGH CENTERS OVER BAHIA BLANCA. A FRONT
EXTENDS ALONG A 998 HPA LOW AT 49S 38W...44S 40W...39S 47W...BAHIA
DE SAN BOROMBON...35S 65W. A TRAIN OF HIGHS EXTENDS ZONALLY NORTH
OF THIS BOUNDARY...CENTERING ON A 1013 HPA HIGH AT 34S 54W...32S
60W...AND A 1015 HPA HIGH AT 31S 63W. A 1002 HPA LOW AT 37S 40W
EXTENDS A FRONT ALONG 35S 39W...31S 41W...29S 45W...PORTO
ALEGRE...URUGUIAIANA...NORTHERN CHACO IN ARGENTINA. THUNDERSTORMS
WERE OCCURRING WELL TO THE NORTH OF THIS BOUNDARY ACROSS SAO PAULO
AND PARANA IN BRASIL.

OVIEDO...SHN (ARGENTINA)
POMIER...SENAMHI (BOLIVIA)
DAVISON...WPC (USA)




Last Updated: 947 AM EST FRI JAN 19 2018