SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
927 AM EDT MON MAY 06 2013

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

SYNOPSIS (VALID FROM 00 UTC MAY 06): AT 200 HPA...SHOWS THE
SUBTROPICAL JET EXTENDING INTO NORTHEASTERN BRASIL-SOUTHERN PARA.
THIS WAS INTERACTING WITH ACTIVE ATLANTIC ITCZ TO ENHANCE
CONVECTION ACROSS THE NORTHERN COAST OF BRASIL INTO AMAPA/THE
GUIANAS AND CENTRAL/NORTHERN PARA. TO THE WEST...A BROAD UPPER
TROUGH EXTENDED ACROSS THE EASTERN PACIFIC WHILE A WEAK RIDGE
EXTENDED ACROSS NORTHERN AMAZONAS IN BRASIL. BEST UPPER DIVERGENCE
EXTENDED IN THE PERIPHERY OF RIDGE AND BETWEEN RIDGE AND
TROUGH...VENTING DEEP CONVECTION ACROSS SOUTHEASTERN
COLOMBIA/WESTERN AMAZONAS AND SOUTHERN PERU.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET EXTENDING
ALONG A 133KT MAXIMA AT 49S 102W...53S 100W...53S 87W...EXITING AT
51S 76W. IT REFORMS AT 52S 63W ALONG 55S 54W...EXITING AT 51S 44W.
THE NORTHERN POLAR EXTENDED ALONG A 132KT MAXIMA AT 33S 123W...A
133KT MAXIMA AT 43S 111W...A 138KT MAXIMA AT 47S 100W...46S
85W...A 136KT MAXIMA AT 43S 73W...47S 58W...37S 53W...EXITING AT
30S 52W. IT REFORMS AT 31S 49W...A 156KT MAXIMA AT 35S 42W...A
148KT MAXIMA AT 38S 30W. THE SUBTROPICAL JET EXTENDED ALONG 40S
100W...40S 87W...EXITING OVER CONCEPCION IN CHILE. IT REFORMS AT
21S 64W ALONG NORTHERN PARAGUAY...A 139KT MAXIMA OVER CURITIBA IN
BRASIL...31S 41W...35S 30W...A 129KT MAXIMA AT 35S 20W.

AT 500 HPA...SHORT WAVE TROUGH IN THE SOUTHERN STREAM IS CROSSING
THE CONTINENT WHILE EXTENDING FROM A LOW IN THE DRAKE PASSAGE TO
ISLA CHILOE ACROSS PATAGONIA. THIS TROUGH WAS FOCUSING ITS ENERGY
ACROSS PATAGONIA/SOUTHERN CHILE. TO THE NORTHEAST...A RIDGE
EXTENDED FROM NORTHEASTERN ARGENTINA INTO THE BUENOS AIRES
PROVINCE/SOUTH ATLANTIC. A TROUGH EXTENDED FROM A LOW AT 38S 50W
TO RIO GRANDE DO SUL TO WESTERN MATO GROSSO. THIS TROUGH WAS
FOCUSING ITS ENERGY ACROSS SANTA CATARINA-PARANA-SAO PAULO-WESTERN
MATO GROSSO DO SUL IN BRASIL.

THE SURFACE ANALYSIS SHOWS A 962 HPA OCCLUDED LOW AT 59S 70W
EXTENDING A FRONT ALONG A 978 HPA LOW AT 54S 60W...48S 62W...A
1006 HPA LOW AT 43S 67W...40S 67W...37S 70W. A 1010 HPA LOW AT 41S
73W EXTENDED A FRONT ALONG 38S 76W...36S 83W. RAINFALL WAS BEING
REPORTED ACROSS SOUTHERN CHILE. A 1017 HPA HIGH CENTERED AT 29S
59W. A 990 HPA LOW AT 37S 22W EXTENDED A FRONT ALONG 31S 32W...A
1010 HPA LOW AT 25S 45W...22S 49W...A 1016 HPA LOW AT 21S
54W...SOUTHEASTERN BOLIVIA...TRINIDAD IN BOLIVIA. SHOWERS AND
ISOLATED THUNDERSTORMS WERE OCCURRING AHEAD OF THIS SYSTEM.

MAQUEDA...DINAC (PARAGUAY)
SILVA DE SOUZA...INMET (BRASIL)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)