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 1307Z Apr 17, 2014)
 
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
907 AM EDT THU APR 17 2014

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

SYNOPSIS (VALID FROM 17 APRIL 00UTC): AT 200 HPA...OVER NORTHERN
SOUTH AMERICA...A WEAK CELL OF THE SUBTROPICAL RIDGE IS ALL THAT
REMAINS OVER AMAZONAS IN WESTERN BRASIL...WITH A SECONDARY CELL
MEANDERING OVER BAHIA/MINAS GERAIS. THE SUBEQUATORIAL RIDGE TO THE
NORTH IS SLOWLY BECOMING THE DOMINANT FEATURE AS IT EXTENDS ACROSS
THE TROPICAL ATLANTIC TO THE GUIANAS. THIS IS VENTING ITCZ RELATED
CONVECTION ALONG THE NORTH COAST OF BRASIL INTO NORTHERN
PARA/SOUTHERN GUIANAS.

AT 250 HPA THE JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS
ALONG 63S 120W...62S 113W...A 142KT MAXIMUM AT 60S 109W...55S
101W...53S 90W...52S 80W...EXITING AT 47S 72W. THE JET REFORMS AT
45S 67W...ALONG 46S 59W...EXITING AT 50S 52W. ANOTHER BRANCH OF
THE SOUTHERN POLAR HAS ITS ENTRANCE AT 52S 49W...ALONG 57S
40W...56S 20W...AND A 135KT MAXIMUM AT 52S 06W. THE NORTHERN POLAR
HAS ITS ENTRANCE AT 49S 104W...ALONG 48S 95W...41S 83W...A 126KT
MAXIMUM AT 37S 75W...36S 69W...39S 62W...A 132KT MAXIMUM AT 44S
53W...46S 41W...EXITING AT 43S 33W. THE SUBTROPICAL JET LIES ALONG
29S 120W...34S 114W...39S 108W...39S 94W...EXITING AT 35S 83W. IT
REFORMS AT 23S 71W...ACROSS ASUNCION...24S 57W...SAO
PAULO...EXITING AT 25S 39W. IT HAS A FINGER OVER THE ATLANTIC THAT
EXTENDS BETWEEN 38S 53W AND 41S 43W.

AT MID LEVELS...PROGRESSIVE SHORT WAVE TROUGH ON THE SOUTHERN
STREAM NOW EXTENDS ALONG 100W TO 47S. A HIGHER AMPLITUDE TROUGH TO
THE EAST EXTENDS NORTH ACROSS CHILE/WESTERN ARGENTINA TO
28S...WHILE A THIRD PERTURBATION NOW EXTENDS ALONG 55W TO 455S.
THESE ARE THEN PRESSING AGAINST A RIDGE OVER THE ATLANTIC THAT
EXTENDS SOUTH ALONG 40W TO 63S.

THE SURFACE ANALYSIS SHOWS A RIDGE ON THE NORTHERN STREAM OVER THE
EASTERN PACIFIC THAT CENTERS ON A 1025 HPA HIGH AT 35S 89W. POLAR
FRONTS ARE STREAMING TO THE SOUTH OF THIS AXIS...WITH ONE THAT
EXTENDS FROM A 970 HPA LOW AT 61S 87W...ALONG A 978 HPA LOW AT 58S
82W...53S 82W...48S 90W...AND 48S 101W. ANOTHER FRONT LIES TO THE
EAST...ORIGINATING ON AN OCCLUDED 966 HPA LOW AT 62S 65W...A 978
HPA LOW AT 59S 54W...54S 51W...A 986 HPA LOW AT 52S 50W...44S
48W...BUENOS AIRES PROVINCE TO MENDOZA IN ARGENTINA. AN OLD FRONT
TO THE NORTH LIES ALONG A 1020 HPA LOW AT 36S 24W...32S 26W...27S
34W...25S 41W...27S 47W...TO 30S 49W. A RIDGE TO THE SOUTH CENTERS
ON TWO 1025 HPA HIGHS...WITH ONE AT 39S 31W AND THE OTHER AT 41S
23W.

ITA...SENAMHI (PERU)
FERNANDES...INMET (BRASIL)
DAVISON...WPC (USA)