THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


SOUTH AMERICAN SYNOPSIS




SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
933 AM EDT FRI SEP 19 2014

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

SYNOPSIS (VALID FROM SEPTEMBER 19 AT 00UTC): AT 200 HPA...OVER
NORTHERN SOUTH AMERICA...A LOW AMPLITUDE RIDGE EXTENDS ACROSS
PARA/AMAZONAS IN BRASIL TO PERU. THIS RIDGE ALSO BRANCHES TO THE
SOUTHEAST ACROSS MATO GROSSO TO SAO PAULO IN BRASIL.
THIS...IN-TURN...FAVORS THE NORTHWARD AMPLIFICATION OF A TROUGH
ALONG THE NORTHEAST COAST OF BRASIL. RIDGE ALOFT IS VENTING
ISOLATED TO SCATTERED CONVECTION OVER THE CONTINENT TO THE NORTH
OF 10S...MOST INTENSE WAS CLUSTERING ACROSS PARA. OTHER ACTIVITY
WAS DOTTING THE SIERRA OF PERU AND THE ALTIPLANO OF BOLIVIA.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH ENTRANCE AT
68S 80W...ALONG 62S 73W...EXITING AT 57S 65W. IT REFORMS AT 47S
67W...ALONG 49S 59W...A 133KT MAXIMUM AT 49S 46W...50S
34W...EXITING AT 53S 24W. THE NORTHERN POLAR LIES ALONG 34S
120W...36S 110W...42S 100W...A 131KT MAXIMUM AT 42S 91W...EXITING
AT 35S 79W. IT REFORMS AT 35S 57W...ALONG 37S 50W...A 142KT
MAXIMUM AT 34S 39W...EXITING AT 31S 29W. THE SUBTROPICAL JET HAS
ITS ENTRANCE AT 18S 82W...ALONG 21S 74W...24S 65W...RIO GRANDE DO
SUL...A 127KT MAXIMUM AT 30S 39W...EXITING AT 21S 27W.

AT 500 HPA...A LONG WAVE TROUGH EXTENDS ALONG 115W/120W TO 30S. AN
INDUCED RIDGE TO THE EAST EXTENDS NORTH-TO-SOUTH ALONG 90W TO THE
POLAR ICE CAP. DOWNSTREAM FROM THIS AXIS...A LOW AMPLITUDE TROUGH
ON THE SOUTHERN STREAM EXTENDS BETWEEN 70W-20W AND TO THE SOUTH OF
50S...WHILE CENTERING ON A CLOSED LOW AT 64S 37W. SHORT WAVE
PERTURBATIONS POPULATE THE NORTHERN STREAM FLOW...WITH ONE ALONG
80W TO 30S AS ANOTHER PULLS ACROSS NORTHERN ARGENTINA. THE LATTER
PROVIDES DYNAMICAL SUPPORT TO ORGANIZED DEEP CONVECTION ACROSS
PARAGUAY-SOUTHERN BRASIL.

AT LOW LEVELS...A RIDGE ON THE SOUTHERN STREAM CENTERS ON A 1017
HPA HIGH AT 52S 83W. AN ELONGATED POLAR FRONT LIES TO THE
NORTH...ORIGINATING ON AN OCCLUDED 1006 HPA LOW AT 45S 67W...THEN
ALONG A 1010 HPA LOW AT 44S 62W...42S 66W...43S 71W...43S 74W...A
1010 HPA LOW AT 41S 77W...38S 79W...35S 84W...35S 89W...37S
93W...40S 96W...A 1006 HPA LOW AT 41S 100W...AND 38S 102W. ANOTHER
FRONT TO THE NORTH ORIGINATES ON AN OCCLUDED 1006 HPA LOW AT 39S
19W...ALONG A 1006 HPA LOW AT 42S 10W...39S 12W...A 1010 HPA LOW
AT 37S 16W...30S 19W...25S 27W...24S 40W...SAO PAULO...27S
53W...30S 54W...A 1010 HPA LOW AT 30S 56W...CORRIENTES-SOUTHEAST
PARAGUAY TO CHACO PARAGUAYO/SOUTHERN BOLIVIA. THIS SUSTAINS
ORGANIZED DEEP CONVECTION ACROSS MID SECTIONS OF SOUTH AMERICA. A
RIDGE TO THE SOUTH CENTERS ON TWO 1025 HPA HIGHS...WITH ONE AT 26S
33W AND THE OTHER AT 36S 39W.

JALFIN...SMN (ARGENTINA)
CAROCA...DMC (CHILE)
DAVISON...WPC (USA)




Last Updated: 933 AM EDT FRI SEP 19 2014