SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
934 AM EDT WED MAY 16 2018

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

SYNOPSIS (VALID FROM MAY 16 AT 0000 UTC): NORTH OVER THE
CONTINENT...AT 200 HPA...AN EAST TO WEST RIDGE TRAVERSES
BRASIL-PERU ALONG 07S...WITH AXIS CENTERING ON A CLOSED HIGH OVER
PARA. THE RIDGE ALOFT IS VENTING DIURNAL CONVECTION ACROSS
PARA-AMAZONAS-ACRE-RONDONIA IN BRASIL...THE CENTRAL/NORTHERN
JUNGLE OF PERU AND ECUADOR.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET EXTENDING A
BRANCH ALONG 73S 75W...A 123KT MAXIMA AT 67S 61W...60S
60W...EXITING AT 52S 57W. ANOTHER BRANCH EXTENDS ALONG 38S
120W...39S 112W...EXITING AT 38S 104W. IT REFORMS AT 40S 49W ALONG
A 126KT MAXIMA AT 42S 40W...45S 32W...46S 23W...A 134KT MAXIMA AT
45S 18W...EXITING AT 41S 09W. THE NORTHERN POLAR JET EXTENDS ALONG
33S 120W...33S 114W...A 126KT MAXIMA AT 31S 110W...31S 104W...A
132KT MAXIMA AT 32S 97W...35S 90W...40S 81W...A 131KT MAXIMA AT
40S 75W...38S 66W...A 123KT MAXIMA AT 36S 59W...36S 49W...A 170KT
MAXIMA AT 38S 42W...38S 36W...A 152KT MAXIMA AT 38S 31W...36S
22W...EXITING AT 31S 14W. THE SUBTROPICAL JET EXTENDS ALONG 30S
120W...28S 107W...28S 97W...34S 83W...EXITING AT 33S 69W. IT
REFORMS AT 28S 49W ALONG 32S 37W...33S 29W...A 130KT MAXIMA AT 31S
22W...27S 17W...EXITING AT 25S 12W.

AT 500 HPA...IN A HIGHLY AMPLIFIED SINUSOIDAL WAVE PATTERN...A
RIDGE ALONG 75W/80W SEPARATES TWO TROUGHS. THE WESTERNMOST EXTENDS
BETWEEN 105W-80W AND TO THE SOUTH OF 24S...WHILE THE ONE TO THE
EAST ENVELOPS AREA BETWEEN 70W-35W AND TO THE SOUTH OF 25S. THIS
IS FOCUSING SHORT WAVE ENERGY ACROSS URUGUAY TO THE SOUTHERN
STATES OF BRASIL. THIS IS PROVIDING THE DYNAMICAL SUPPORT TO
ORGANIZED DEEP CONVECTION ACROSS PARAGUAY-MISIONES IN ARGENTINA TO
MATO GROSSO DO SUL IN BRASIL.

THE SURFACE ANALYSIS SHOWS A 978 HPA OCCLUDED LOW AT57S 37W
EXTENDING A FRONT INTO A 978 HPA TRIPLE POINT LOW AT 57S 35W...53S
35W...48S 45W...47S 55W...52S 61W...54S 61W...A 1010 HPA LOW AT
55S 64W...54S 65W...54S 69W...56S 70W...A 1014 HPA LOW AT 60S
71W...60S 74W...62S 77W...65S 8W. A 1025 HPA HIGH CENTERS AT 55S
79W AND EXTEND A RIDGE NORTHEAST INTO A 1021 HPA HIGH AT 48S
72W...A 1025 HPA HIGH AT 41S 67W...AND THIS EXTENDS A RIDGE INTO
NORTHEASTERN ARGENTINA AND URUGUAY. A 1002 HPA OCCLUDED LOW
CENTERS AT 41S 52W AND EXTENDS AN OCCLUDED FRONT INTO THE CENTRAL
BUENOS AIRES PROVINCE. A FRONT EXTENDS ALONG A 990 HPA LOW AT 41S
37W...38S 38W...36S 40W...A 1002 HPA LOW AT 35S 43W...32S
46W...30S 51W...29S 54W...A 1010 HPA LOW AT 27S 56W...24S
58W...22S 63W. A 1017 HPA HIGH CENTERS AT 27S 51W. TO THE
NORTHEAST OF THIS HIGH...A TROUGH EXTENDS FROM 32S 46W ALONG 28S
49W...24S 51W. A FRONT EXTENDS OFF THE COAST OF EASTERN BRASIL
ALONG A 1018 HPA LOW AT 22S 16W...21S 19W...21S 21W...21S
29W...22S 38W.

BALBINO...INMET (BRASIL)
DIAZ...INUMET (URUGUAY)
DAVISON/GALVEZ...WPC (USA)