Prognostic Meteorological Discussion
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SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
928 AM EST THU FEB 11 2016

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

SYNOPSIS (VALID FROM FEB 11 AT 0000 UTC): NORTH OVER THE
CONTINENT...AT 200 HPA...BROAD CELL OF THE SUBTROPICAL RIDGE
EXTENDS ACROSS MID SECTIONS OF SOUTH AMERICA...DOMINATING FLOW TO
THE SOUTH OF 13S WHILE ANCHORING ON A CLOSED HIGH OVER CHACO
PARAGUAYO. AN ELONGATED TROUGH LIES TO THE NORTH...WITH AXIS WEST
ALONG 10S TO AMAZONAS IN BRASIL. THE RIDGE ALOFT IS VENTING DEEP
CONVECTION ACROSS PERU-BOLIVIA-PARAGUAY TO SAO PAULO IN BRASIL.
THE TROUGH...MEANWHILE...IS ENHANCING EQUATORIAL CONVECTION ACROSS
NORTHERN PARA-AMAZONAS TO NORTHERN PERU/SOUTHERN COLOMBIA.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET FORMING AT
55S 87W ALONG A 133KT MAXIMA AT 57S 80W...59S 66W...A 152KT MAXIMA
AT 54S 53W...A 131KT MAXIMA AT 47S 45W...45S 36W...A 134KT MAXIMA
AT 56S 29W. THE NORTHERN POLAR JET FORMS AT 42S 99W ALONG 49S
85W...52S 69W...42SX 48W...40S 40W...46S 28W. THE SUBTROPICAL JET
FORMS AT 27S 81W ALONG 35S 66W...32S 48W...31S 36W...EXITING AT
33S 22W.

AT 500 HPA...A RIDGE EXTENDS FROM 45S 120W...ALONG 55S 110W...TO
65S 100W. THIS IS INDUCING THE NORTHWARD AMPLIFICATION OF A TROUGH
FROM 63S 83W...ALONG 50S 98W...40S 100W...TO 33S 102W. AS IT NEARS
THE CONTINENT IT IS DISPLACING A SHORT WAVE TROUGH TO THE
EAST...AS THE LATTER EXTENDS INTO CENTRAL CHILE/CUYO IN ARGENTINA.
THIS IS PROVIDING DYNAMICAL SUPPORT TO CONVECTION ACROSS CENTRAL
PROVINCES IN ARGENTINA. FARTHER EAST...A RIDGE EXTENDS
NORTH-TO-SOUTH ALONG 65W TO THE DRAKE PASSAGE. OVER THE
ATLANTIC...MEANWHILE...BROAD TROUGH DOMINATES THE FLOW BETWEEN
55W-15W AND TO THE SOUTH OF 25S...WITH AXIS ANCHORING ON A CLOSED
LOW NEAR 60S 37W.

A 974 HPA OCCLUDED LOW CENTERS AT 61S 81 EXTENDS A FRONT ALONG63S
85W...63S 75W...A 982 HPA LOW AT 58S 68W...54S 69W...54S 76W...A
998 HPA LOW AT 53S 83W...50S 83W...49S 88W...A 998 HPA LOW AT 53S
82W. A 1021 HPA HIGH CENTERS OVER THE EASTERN PACIFIC AT 37S 84W.
A 1017 HPA HIGH CENTERS AT 39S 54W OVER THE SOUTH ATLANTIC. A 1006
HPA LOW AT 34S 28W EXTENDS A FRONT ALONG 29S 33W...27S 38W...26S
49W...30S 59W. THUNDERSTORMS WERE OCCURRING AHEAD OF THIS SYSTEM
IN SOUTHEASTERN BRASIL.

ENRIQUEZ...INAMHI (ECUADOR)
LOPEZ...SMN (ARGENTINA)
GALVEZ/DAVISON...WPC (USA)

$$





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