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000
FXSA20 KWBC 291338
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
938 AM EDT WED JUL 29 2015

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

SYNOPSIS (VALID FROM JUL 29 AT 0000 UTC): THE 200 HPA ANALYSIS
SHOWS NEAR ZONAL WESTERLY FLOW ACROSS NORTHERN SOUTH
AMERICA...WITH DIURNAL CONVECTION CONFINING TO EQUATORIAL SOUTH
AMERICA. MOST ACTIVE IS BUILDING OVER NORTHERN
PARA-AMAZONAS-RORAIMA IN BRASIL...INTO SOUTHERN COLOMBIA-NORTHERN
PERU AND EASTERN ECUADOR. OVER NORTHEAST
BRASIL...MEANWHILE...TRADE WIND EASTERLY CONVERGENCE FAVORS
SHALLOW CONVECTION ACROSS THE NORTHEAST STATES OF BRASIL.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH ENTRANCE AT
46S 124W...THEN ALONG 43S 113W...EXITING AT 39S 103W. IT REFORMS
BETWEEN 37S 80W AND 41S 65W. IT REFORMS AT 47S 51W...ALONG 54S
32W...A 122KT MAXIMUM AT 49S 14W...EXITING AT 41S 03W. THE
NORTHERN POLAR LIES ALONG 37S 120W...31S 100W...A 145KT MAXIMUM AT
36S 71W...38S 60W...EXITING AT 49S 36W. THE SUBTROPICAL JET LIES
ALONG 31S 120W...A 152KT MAXIMUM AT 28S 107W...25S 96W...A 137KT
MAXIMUM AT 28S 85W...33S 62W...32S 49W...EXITING AT 28S 41W.

AT 500 HPA...THE MID LEVEL ANALYSIS SHOWS A BROAD/LONG WAVE TROUGH
DOMINATING FLOW OVER THE EASTERN PACIFIC...AS IT ENVELOPS AREA
BETWEEN 110W-70W AND TO THE SOUTH OF 20S...WITH SHORT WAVE
VORTICES STREAMINGA CROSS CENTRAL CHILE TO ARGENTINA. SHORT WAVE
RIDGE EXTENDS OVER MID SECTIONS OF SOUTH AMERICA...FAVORING A CAP
INVERSION AND FAIR WEATHER CONDITIONS.

AT LOW LEVELS...BROAD TROUGH DOMINATES FLOW ACROSS THE EASTERN
PACIFIC...WITH A POLAR FRONT EXTENDING FROM AN OCCLUDED 966 HPA
LOW AT 60S 100W...A 972 HPA TRIPLE POINT LOW AT 62S 101W...61S
94W...A 970 HPA LOW AT 58S 94W...57S 89W...54S 88W...A 978 HPA LOW
AT 53S 89W...49S 85W...41S 90W...AND 34S 102W. ANOTHER FRONT
EXTENDS FROM THE WESTERN ATLANTIC TO THE EASTERN PACIFIC...WITH AN
OCCLUDED 990 HPA LOW AT 58S 49W. THE FRONT LIES ALONG A 998 HPA
LOW AT 54S 39W...52S 38W...46S 47W...A 1010 HPA LOW AT 44S
52W...39S 51W...RIO DE LA PLATA-MENDOZA IN ARGENTINA...33S
71W...34S 76W...A 1014 HPA LOW AT 35S 80W...33S 82W...A 1010 HPA
LOW AT 32S 87W...28S 90W...AND 25S 96W. A RIDGE OVER THE PACIFIC
SPLITS IN TWO CELLS...WITH A 1017 HPA HIGH AT 26S 80W...WHILE A
1019 HPA HIGH LIES NEAR 37S 72W. A BROAD RIDGE OVER THE ATLANTIC
ANCHORS ON A 1033 HPA HIGH AT 36S 24W.

CHARPENTIER...DMC (CHILE)
ROMERO...DMC (CHILE)
DAVISON...WPC (USA)
$$





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