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FXSA20 KWBC 011302
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
901 AM EDT TUE SEP 01 2015

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

SYNOPSIS (VALID FROM SEP 01 AT 0000 UTC): THE ANALYSIS AT 200 HPA
SHOWS A CLOSED HIGH OF THE SUBTROPICAL RIDGE OVER THE NORTH COAST
OF PERU. THIS HIGH EXTENDS A RIDGE ALONG THE COAST TO NORTHERN
CHILE...THEN SOUTHEAST ACROSS NORTHERN ARGENTINA-URUGUAY. THE
RIDGE UNDERCUTS A TROUGH TO THE NORTH...AS THE LATTER EXTENDS
ALONG 20S 30W...13S 50W...TO RONDONIA/ACRE IN WESTERN BRASIL.
UNDER INFLUENCE OF THE UPPER TROUGH...SCATTERED DEEP CONVECTION IS
BUILDING ACROSS AMAZONAS-ACRE-RONDONIA INTO CENTRAL/NORTHERN
JUNGLE OF PERU AND NORTHERN PORTIONS OF BOLIVIA.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS ALONG
59S 120W...A 148KT MAXIMUM AT 63S 90W...A 127KT MAXIMUM AT 60S
65W...EXITING AT 58S 57W. IT REFORMS AT 47S 59W...ALONG 41S
47W...39S 29W...38S 14W...AND 49S 01W. THE NORTHERN POLAR LIES
ALONG 39S 120W...41S 115W...35S 107W...19S 102W...A 130KT MAXIMUM
AT 26S 90W...36S 77W...A 152KT MAXIMUM AT 38S 70W...A 169KT
MAXIMUM AT 36S 50W...A 130KT MAXIMUM AT 34S 30W...A 126KT MAXIMUM
AT 33S 20W...EXITING AT 37S 04W. THE SUBTROPICAL JET HAS ITS
ENTRANCE AT 14S 104W...ALONG 20S 90W...32S 75W...33S 59W...EXITING
AT 26S 39W. THE SUBTROPICAL JET REFORMS AT 15S 30W...ALONG 20S
18W...23S 08W...AND 24S 00W.

THE 500 HPA ANALYSIS SHOWS A TIGHT BELT OF UPPER LATITUDE
WESTERLIES DOMINATING THE SOUTHEAST PACIFIC-ANTARCTIC PENINSULA. A
SKEWED RIDGE TO THE NORTH EXTENDS FROM 30S 102...ALONG 43S
100W...45S 80W...TIERRA DEL FUEGO TO 60S 50W. THIS RIDGE UNDERCUTS
A LONG WAVE TROUGH TO THE NORTH...AS THE LATTER EXTENDS ALONG 40S
80W...A LOW AT 37S 93W...30S 95W...TO 17S 103W. DOWNSTREAM FROM
THIS AXIS...A BROAD RIDGE EXTENDS ACROSS MID SECTIONS OF SOUTH
AMERICA TO CENTRAL ARGENTINA...WHILE FARTHER EAST A BROAD TROUGH
LIES BETWEEN 55W-00W AND TO THE SOUTH OF 25S.

AT LOW LEVELS...RIDGE OVER THE EASTERN PACIFIC DOMINATES THE
SOUTHERN STREAM FLOW...AS IT CENTERS ON TWO 1037 HPA HIGHS AT 43S
93W AND 44S 86W. THIS BRANCHES INTO A POLAR RIDGE OVER ARGENTINA
THAT ANCHORS ON A 1035 HPA HIGH AT 41S 65W. BROAD POLAR TROUGH TO
THE EAST DOMINATES THE FLOW OVER THE SOUTH ATLANTIC...WITH AN
ELONGATED FRONT EXTENDING ALONG A 1010 HPA LOW AT 39S 08W...35S
11W...32S 16W...32S 25W...35S 35W...A 1002 HPA LOW AT 38S
39W...34S 40W...33S 44W...A 1010 HPA LOW AT 33S 47W...RIO GRANDE
DO SUL/ NORTHERN URUGUAY TO NORTHWEST ARGENTINA.

ROMERO...DMC (CHILE)
FARINA...DMH (PARAGUAY)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

$$




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