Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXSA20 KWBC 311328
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
927 AM EDT MON AUG 31 2015

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

SYNOPSIS (VALID FROM AUG 31 AT 0000 UTC): AT 200 HPA...A SKEWED
RIDGE EXTENDS ACROSS PERU TO NORTHERN CHILE...WHERE IT THEN
BRANCHES TO THE SOUTHEAST ACROSS NORTHERN ARGENTINA/SOUTHERN
BRASIL TO THE WESTERN ATLANTIC. THE RIDGE ALOFT UNDERCUTS A TROUGH
TO THE NORTH...AS THE LATTER EXTENDS FROM 34S 30W...ALONG 20S
40W...TO NORTHERN BOLIVIA. IN THIS PATTERN...SCATTERED DEEP
CONVECTION CLUSTERS ACROSS AMAZONAS IN BRASIL TO NORTHERN JUNGLE
OF PERU.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET EXTENDING
ALONG 60S 120W...A 123KT MAXIMA AT 64S 90W...EXITING AT 56S 72W.
ANOTHER BRANCH FORMS AT 46S 72W ALONG 44S 51W...39S 29W...45S 15W.
THE NORTHERN POLAR JET EXTENDS ALONG 39S 120W...A 127KT MAXIMA AT
30S 113W...22S 105W...A 133KT MAXIMA AT 23S 99W...A 157KT MAXIMA
AT 35S 80W...A 171KT MAXIMA AT 40S 60W...A 148KT MAXIMA AT 37S
40W...EXITING AT 34S 22W. THE SUBTROPICAL JET FORMS AT 17S 100W
ALONG 24S 88W...30S 80W...33S 69W...32S 56W...EXITING AT 27S 46W.
IT REFORMS AT 17S 31W ALONG 23S 19W.

AT 500 HPA...TIGHT BELT OF UPPER LATITUDE WESTERLIES DOMINATE THE
FLOW OVER THE SOUTHEAST PACIFIC TO THE SOUTH OF 50S...WITH SHORT
WAVE PERTURBATIONS STREAMING TOWARDS THE ANTARCTIC PENINSULA.
UNDER INFLUENCE OF A RIDGE ALONG 80W...A TROUGH AMPLIFIED ACROSS
THE ANTARCTIC PENINSULA TO PATAGONIA IN ARGENTINA. MEANWHILE...A
TROUGH ON THE NORTHERN STREAM EXTENDS FROM 43S 83W...ALONG 38S
90W...30S 100W...TO 18S 108W. THIS IS FOCUSING SHORT WAVE ENERGY
ACROSS CENTRAL CHILE INTO ARGENTINA.

THE SURFACE ANALYSIS SHOWS A 982 HPA LOW AT 60S 65W EXTENDING A
FRONT ALONG 59S 67W...59S 60W...55S 57W...50S 59W...A 1006 HPA LOW
AT 48S 63W...46S 63W...44S 70W...43S 76W. RAINFALL WAS OCCURRING
IN PARTS OF SOUTHERN CHILE. TO THE EAST...A 1010 HPA LOW AT 35S
27W EXTENDS A FRONT ALONG 33S 36W...33S 46W...A 1010 HPA LOW AT
34S 78W...33S 61W...32S 65W...A 1014 HPA LOW AT 39S 68W...37S
72W...33S 78W...30S 85W.

ROMERO...DMC (CHILE)
FARINA...DMH (PARAGUAY)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.