Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
 
South American Synoptic Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1317Z May 04, 2015)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product


SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
917 AM EDT MON MAY 04 2015

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

SYNOPSIS (VALID FROM MAY 04 AT 00UTC): AT 200 HPA A SHORT WAVE
RIDGE EXTENDS ACROSS NORTHWEST SOUTH AMERICA WHILE ANCHORING ON A
CLOSED HIGH OVER CENTRAL JUNGLE OF PERU. A TROUGH TO THE EAST
STRETCHES ALONG 30S 27W...15S 40W TO NORTHEAST BRASIL. THE LATTER
IS ENHANCING CONVECTIVE DEVELOPMENT ALONG THE NORTH COAST OF
BRASIL INTO THE AMAZON DELTA REGION. RIDGE ALOFT...MEANWHILE...IS
VENTING DEEP CONVECTION ACROSS PERU-AMAZONAS IN BRASIL.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH ENTRANCE AT
58S 102W...ALONG 63S 99W...EXITING AT 67S 98W. IT REFORMS AT 66S
79W...ALONG 60S 76W...54S 74W...50S 69W...EXITING AT 49S 63W. THE
NORTHERN POLAR HAS ITS ENTRANCE AT 32S 56W...ALONG 36S 51W...A
142KT MAXIMUM AT 40S 46W...EXITING AT 51S 37W. THE SUBTROPICAL JET
HAS ITS ENTRANCE AT 21S 97W...ALONG 27S 72W...A 124KT MAXIMUM AT
26S 58W...28S 52W...EXITING AT 37S 41W.

AT 500 HPA...IN A SPLIT FLOW PATTERN...A RIDGE DOMINATES THE
SOUTHERN STREAM FLOW...AS IT EXTENDS FROM 60S 90W TO THE
BELLINGSHAUSEN SEA. THE TROUGH TO THE NORTH EXTENDS FROM A LOW AT
53S 90W TO 45W. A SHORT WAVE TROUGH TO THE NORTH EXTENDS BETWEEN
110W-90W AND TO THE SOUTH OF 15S...WHILE CENTERING ON A CLOSED LOW
AT 27S 105W. A HIGH AMPLITUDE TROUGH DOMINATES FLOW OVER THE
WESTERN ATLANTIC...AS IT EXTENDS BETWEEN 70W-45W AND TO THE SOUTH
OF 20S. THE TROUGH IS FOCUSING SHORT WAVE ENERGY ACROSS MID
SECTIONS OF SOUTH AMERICA...WHERE IT SUSTAINS ORGANIZED DEEP
CONVECTION.

AT LOW LEVELS...A RIDGE OVER THE EASTERN PACIFIC CENTERS ON A 1025
HPA HIGH AT 36S 85W. A SUBTROPICAL LOW TO THE NORTH-NORTHWEST
CENTERS ON A 1002 HPA LOW AT 26S 104W. EAST OVER THE
ATLANTIC...BROAD TROUGH DOMINATES THE FLOW...WITH A POLAR FRONT
THAT EXTENDS ALONG A 974 HPA LOW AT 57S 42W...53S 43W...A 978 HPA
LOW AT 51S 47W...48S 41W...A 1002 HPA LOW AT 40S 45W...31S
50W...PARAGUAY TO SOUTHERN BOLIVIA. THIS SUSTAINS A SQUALL LINE
ACROSS SOUTHERN STATES OF BRASIL TO MATO GROSSO DO SUL.

CHARPENTIER...DMC (CHILE)
SCHNEIDER...INMET (BRASIL)
UNSIHUAY...UNALM (PERU)
DAVISON...WPC (USA)