SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
901 AM EST WED NOV 18 2009
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
 
NOTE: DUE TO PRESSING OPERATIONAL REQUIREMENTS...THIS PRODUCT
WILL BE SUSPENDED UNTIL DECEMBER 02 2009. GRAPHICAL PRODUCTS...
HOWEVER...WILL BE ISSUED.

SYNOPSIS (VALID FROM 00Z NOV 18). A 200 HPA HIGH NEAR 18S 57W
ANCHORS A RIDGE OVER THE CONTINENT THAT EXTENDS WEST-TO-EAST
BETWEEN 08S-30S. AN ELONGATED TROUGH LIES TO THE NORTH...WITH
AXIS ALONG 05S 30W...NORTHERN COAST OF BRASIL TO A LOW JUST SOUTH
OF SURINAME. IN A CONVERGENT PATTERN ALOFT...LITTLE TO NO
CONVECTION IS OBSERVED OVER THE CONTINENT TO THE NORTH OF 08S AND
TO THE EAST OF 60W. MOST ACTIVE CONVECTION IS BUILDING ACROSS
MATO GROSSO-MINAS GERAIS/ESPIRITO SANTO...THE ALTIPLANO OF
BOLIVIA...AMAZONAS IN WESTERN BRASIL AND THE PERUVIAN/ECUADORIAN
JUNGLE.

THE 250 HPA JET ANALYSIS SHOWS A FINGER OF THE SOUTHERN POLAR
WITH AXIS ALONG 67S 113W...53S 107W...EXITING AT 46S 93W. IT
REFORMS AT 39S 82W...ALONG 44S 74W...45S 54W...A 158KT MAXIMUM AT
45S 48W...47S 37W...EXITING AT 37S 22W. THE NORTHERN POLAR HAS
ITS ENTRANCE AT 38S 119W...ALONG 38S 108W...A 152KT MAXIMUM AT
34S 98W...JUAN FERNANDEZ ISLAND...A 147KT MAXIMUM AT 34S
72W...BUENOS AIRES PROVINCE....40S 45W...29S 20W...AND 48S 01W.
THE SUBTROPICAL JET HAS ITS ENTRANCE AT 29S 106W...ALONG 26S
80W...LA SERENA CHILE...SOUTHERN URUGUAY...36S 44W...EXITING AT
27S 25W.

A 500 HPA RIDGE EXTENDS SOUTH ALONG 120W. THIS SUSTAINS THE
NORTHWARD AMPLIFICATION OF A SOUTHERN STREAM POLAR SURGE BETWEEN
95W-68W TO 43S. THIS IS PHASING WITH A NORTHERN STREAM VORTEX
THAT EXTENDS FROM 40S 77W TO 25S 80W. FARTHER EAST...A CLOSED LOW
TO THE EAST OF THE MALVINAS/FALKLAND ISLANDS SUSTAINS A LOW
AMPLITUDE TROUGH OFF THE COAST OF PATAGONIA. A SHORT WAVE RIDGE
ALONG 27W/30W SEPARATES THE LATTER FROM A HIGHER AMPLITUDE TROUGH
THAT EXTENDS ALONG 10W TO 20S.

A TROUGH OVER THE FAR EASTERN PACIFIC CENTERS ON AN OCCLUDED 978
HPA LOW AT 59S 88W. A POLAR FRONT TO THE EAST AND NORTH LIES
ALONG A 980 HPA LOW AT 58S 80W...56S 76W...54S 77W...A 986 HPA
LOW AT 51S 80W...46S 79W...TO 40S 88W. A WEAK/DYING OCCLUSION
MOVED OVER PATAGONIA WHERE IT FAVORS LIGHT RAINFALL. FARTHER
EAST...OVER THE ATLANTIC...A 974 HPA LOW AT 51S 55W EXTENDS A
FRONT ACROSS THE MALVINAS...53S 59W...A 990 HPA TRIPLE POINT LOW
AT 48S 43W...41S 43W...A 1006 HPA LOW AT 39S 46W...34S 50W...A
1006 HPA LOW OVER EASTERN URUGUAY...CORDOBA-MENDOZA IN ARGENTINA.
SCATTERED DEEP CONVECTION WAS BUILDING ALONG AND NORTH OF THIS
BOUNDARY...MOST INTENSE OVER URUGUAY/SOUTHERN BRASIL AND NEAR
CORDOBA. A 1011 HPA POLAR HIGH LIES TO THE SOUTH NEAR 37S 58W.
EAST OF THIS SYSTEM...A BROAD RIDGE OVER THE ATLANTIC CENTERS ON
A 1021 HPA HIGH AT 30S 34W. AN ELONGATED FRONT TO THE NORTH LIES
ALONG 22S 20W...20S 26W...18S 31W...VITORIA-SAO PAULO TO
PARANA/SANTA CARINA IN SOUTHERN BRASIL. 

FERNANDES...CHM (BRASIL)
GARCIA...SENAMHI (PERU)
DAVISON...HPC (USA)