SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1030 AM EDT THU MAY 23 2013

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

SYNOPSIS (VALID FROM 00 UTC MAY 23): A CELL OF THE SUBTROPICAL
RIDGE WAS ESTABLISHING OVER NORTHERN PERU...WHILE A TROUGH
EXTENDED OVER EASTERN AMAZONAS IN BRASIL. STRONGEST CONVECTION WAS
OCCURRING OVER NORTHERN PERU/CENTRAL AMAZONAS IN BRASIL. TO THE
EAST...A CELL OF THE SUBTROPICAL RIDGE EXTENDED INTO THE AMAZON
DELTA. STRONGEST CONVECTION WAS OCCURRING OFF THE COASTS OF AMAPA
IN ASSOCIATION WITH ARRIVING TROPICAL WAVE.

THE JET ANALYSIS SHOWS THE SOUTHERN POLAR JET FORMING AT 51S 84W
ALONG A 142KT MAXIMA AT 52S 66W...131KT MAXIMA OVER THE
MALVINAS/FALKLANDS...EXITING AT 53S 46W. THE NORTHERN POLAR
EXTENDED ALONG 33S 120W...39S 104W...A 122KT MAXIMA AT 43S
84W...EXITING AT 44S 61W. THE SUBTROPICAL JET FORMED AT 16S 91W
ALONG 24S 78W...A 126KT MAXIMA AT 27S 61W...A 131KT MAXIMA AT 26S
50W...A 147KT MAXIMA AT 25S 40W...A 130KT MAXIMA AT 22S 30W.

AT 500 HPA...THE MID-LEVEL ANALYSIS SHOWS A WELL ESTABLISHED
TROUGH IN THE SOUTHERN STREAM CENTERING OVER THE ANTARCTIC
PENINSULA/BELLINGSHAUSEN SEA. A TIGHT BELT OF WESTERLIES EXTENDED
OVER SOUTHERN CHILE/PATAGONIA. A  NORTHERN STREAM TROUGH EXTENDED
FROM CENTRAL CHILE TO THE NORTHWEST TO A LOW AT 20S 90W. OVER THE
SOUTH ATLANTIC...A BROAD TROUGH WAS EXITING ALONG 20W WHILE STILL
FOCUSING ITS ENERGY ACROSS SOUTHEASTERN BRASIL.

THE SURFACE ANALYSIS SHOWS A 996 HPA LOW AT 48S 72W EXTENDING A
FRONT ALONG 46S 77W...41S 74W...A 1010 HPA LOW AT 41S 78W...36S
80W. A 1014 HPA LOW AT 45S 47W EXTENDED A FRONT ALONG 38S
48W...35S 56W...EASTERN BUENOS AIRES PROVINCE. A 1021 HPA POLAR
HIGH CENTERED OVER SOUTHERN CORDOBA IN ARGENTINA. A 1014 HPA HIGH
AT 28S 44W EXTENDED A FRONT ALONG PARANA IN BRASIL. A 1010 HPA LOW
AT 26S 09W EXTENDED A FRONT ALONG 19S 16W...17S 30W...20S
40W...SOUTHERN MINAS GERAIS...SOUTHERN MATO GROSSO DO
SUL...EASTERN BOLIVIA. WIDESPREAD RAINFALL WAS OCCURRING ALONG
THIS BOUNDARY OVER AND EAST OF PARAGUAY INTO SOUTHEASTERN BRASIL.

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