Prognostic Meteorological Discussion
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SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1015 AM EST MON JAN 23 2017

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

SYNOPSIS (VALID FROM JANUARY 23 AT 0000 UTC): AT 200 HPA...THE
SUBTROPICAL RIDGE NOW EXTENDS BETWEEN 100W-60W WHILE CENTERING ON
A CLOSED HIGH OVER THE EASTERN PACIFIC NEAR 22S 83W. SHORT WAVE
PERTURBATIONS STREAM TO THE SOUTH AND AMPLIFY TO THE EAST...WITH
ONE ENTERING CENTRAL CHILE/CUYO IN ARGENTINA AS A HIGHER AMPLITUDE
TROUGH EXTENDS FROM SOUTHERN BRASIL TO MATO GROSSO. THE LATTER IS
ENHANCING CONVECTIVE DEVELOPMENT ACROSS SOUTHEAST-CENTRAL
BRASIL...WHILE THE FORMER IS ENHANCING CONVECTIVE ACTIVITY ACROSS
CENTRAL/NORTHERN PROVINCES IN ARGENTINA.

AT 250 HPA...THE JET ANALYSIS SHOWS THE SOUTHERN POLAR LIES ALONG
64S 120W...64S 102W...60S 92W...53S 96W...EXITING AT 48S 105W. IT
REFORMS AT 47S 96W...THEN ALONG A 133KT MAXIMUM AT 49S 90W...A
138KT MAXIMUM AT 51S 80W...53S 70W...EXITING AT 52S 54W. THE
NORTHERN POLAR HAS ITS ENTRANCE AT 49S 109W...THEN ALONG 41S
120W...32S 122W...30S 115W...A 131KT MAXIMUM AT 32S 111W...A 146KT
MAXIMUM AT 38S 103W...46S 90W...49S 73W...48S 57W...45S 41W...47S
29W...49S 18W...44S 12W...EXITING AT 40S 10W. THE SUBTROPICAL JET
HAS ITS ENTRANCE AT 28S 111W...THEN ALONG 35S 102W...40S
93W...EXITING AT 40S 83W. IT HAS A FINGER THAT LIES BETWEEN 41S
55W AND 42S 35W.

AT 500 HPA...A RIDGE EXTENDS FROM A HIGH NEAR 40S 136W...ALONG 53S
110W TO 63S 90W. THE RIDGE UNDERCUTS A TROUGH TO THE EAST AND
NORTH THAT EXTENDS FROM 60S 80W...ALONG 48S 100W...A LOW AT 43S
11W...30S 120W...TO 20S 125W. BROAD CELL OF THE SUBTROPICAL RIDGE
TO THE NORTH...MEANWHILE...CENTERS ON A CLOSED HIGH AT 27S 87W.
OVER THE ATLANTIC...IN A TIGHT BELT OF MID LATITUDE
WESTERLIES...PROGRESSIVE PERTURBATIONS ARE STREAMING AWAY FROM THE
CONTINENT...WITH ONE PULLING ALONG 35W AND SOUTH OF 40S.

AT LOW LEVELS...AN ELONGATED FRONT LIES ALONG A 1002 HPA LOW AT
54S 49W...49S 53W...49S 63W...A 1002 HPA LOW AT 51S 69W...48S
72W...49S 76W...A 998 HPA LOW AT 52S 79W...47S 84W...44S 92W...TO
A 1002 HPA LOW AT 43S 103W. ANOTHER TO THE NORTH LIES ALONG A 990
HPA LOW AT 49S 24W...45S 26W...43S 31W...A 1014 HPA LOW AT 42S
34W...40S 38W...37S 46W...36S 56W...BUENOS AIRES...RIO
NEGRO...PUERTO MONTT CHILE...A 1018 HPA LOW AT 44S 76W...41S
77W....38S 80W...37S 88W...40S 94W...TO A 1010 40S 97W. THE
CONTINENT SEPARATES TWO RIDGES ON THE NORTHERN STREAM FLOW...WITH
THE WESTERNMOST ANCHORING ON A 1023 HPA HIGH AT 32S 86W AND THE
EASTERNMOST ON A 1021 HPA HIGH AT 43S 51W.

DURAN...SMN (ARGENTINA)
TEPES...DMC (CHILE)
DAVISON...WPC (USA)
$$




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