067
FXSA20 KWBC 261309
PMDSA
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
909 AM EDT TUE AUG 26 2008
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SYNOPSIS (VALID FROM 00Z AUG 26). THE SUBTROPICAL HIGH IS
INITIALIZED OVER THE CONTINENT...ENVELOPING AREA NORTH OF 20S AND
WEST OF 55W/60W...AND WITH A CLOSED CIRCULATION AT 200 HPA
CENTERING NEAR 15S 70W. THE HIGH ALSO RIDGES SOUTH-SOUTHEAST
ACROSS ARGENTINA TO THE MALVINAS/FALKLAND ISLANDS...WHICH IN-TURN
FAVORS THE NORTHWARD AMPLIFICATION OF A TROUGH ALONG 30S 40W...
20S 40W...TO 10S 50W. THE RIDGE/TROUGH PATTERN OVER THE CONTINENT
FAVORS ORGANIZED DEEP CONVECTION ON CONTINENTAL AREA NORTH OF 06S
AND WEST OF 50W. THIS REMAINS UNUSUALLY ACTIVE FOR THIS TIME OF
THE YEAR...AND IT IS QUITE REMINISCENT OF A MID OCTOBER PATTERN.
THE 250 HPA ANALYSIS SHOWS THE SOUTHERN POLAR WITH ENTRANCE AT
40S 107W...34S 92W...EXITING AT 43S 79W. IT REFORMS AT 63S
69W...ALONG 60S 44W...59S 30W...AND 61S 14W. THE NORTHERN POLAR
LIES ALONG 37S 120W...33S 109W...29S 96W...A 144KT MAXIMUM AT 28S
90W...30S 84W...A 144KT MAXIMUM AT 37S 72W...44S 63W...EXITING AT
44S 52W. IT REFORMS AT 40S 29W...ALONG 33S 16W...AND 35S 00W. THE
SUBTROPICAL JET LIES ALONG 28S 120W...A 144KT MAXIMUM AT 27S
110W...26S 86W...36S 61W...29S 45W...EXITING AT 22S 38W. IT
REFORMS AT 21S 34W...ALONG 26S 20W...AND A 148KT MAXIMUM AT 29S
04W.
AT 500 HPA...A BROAD TROUGH EXTENDS ACROSS THE EASTERN PACIFIC...
ENVELOPING AREA BETWEEN 110W-65W AND SOUTH OF 20S...WHILE
CENTERING ON A CLOSED LOW AT 46S 97W. THIS TROUGH IS FOCUSING ITS
SHORT WAVE ENERGY INTO CENTRAL/SOUTHERN CHILE. AN INDUCED RIDGE
TO THE WEST EXTENDS SOUTH FROM A HIGH NEAR 22S 57W...ACROSS RIO
DE LA PLATA TO THE MALVINAS. A SHORT WAVE TROUGH TO THE EAST
ANCHORS ON A LOW NEAR 35S 44W. ON THE SOUTHERN STREAM...A LOW
AMPLITUDE TROUGH EXTENDS BETWEEN 80W-00W AND SOUTH OF 55S/60S.
THE SURFACE ANALYSIS SHOWS A BROAD TROUGH OVER THE FAR EASTERN
PACIFIC...WITH AN OCCLUDED 984 HPA LOW AT 45S 96W. POLAR FRONTS
REVOLVE AROUND THIS AXIS...WITH ONE EXTENDING FROM A 1000 HPA LOW
AT 39S 84W...ALONG 30S 83W...TO 26S 90W. ANOTHER EXTENDS ALONG A
992 HPA TRIPLE POINT LOW AT 49S 77W...45S 72W...A 1000 HPA LOW AT
42S 75W...JUAN FERNANDEZ ISLAND...25S 85W...AND 20S 96W. A
THIRD...AND ELONGATED...FRONT EXTENDS ALONG A 1002 HPA LOW AT 51S
67W...A 1004 HPA LOW AT 51S 60W...A 1008 HPA LOW AT 48S 53W...46S
58W...A 1008 HPA LOW AT 45S 65W...NORTHERN PATAGONIA...A 1008 HPA
LOW AT NORTH OF TEMUCO CHILE...33S 75W...A 1012 HPA LOW AT 29S
78W...AND 21S 84W. THESE SYSTEMS COMBINE IN SUPPORT OF SCATTERED
RAINFALL ACROSS CENTRAL AND SOUTHERN CHILE. A THERMAL TROUGH OVER
CUYO IN WESTERN ARGENTINA CENTERS ON A 1008 HPA LOW AT 33S 66W.
FARTHER EAST...OFF THE COAST...A 1012 HPA LOW AT 34S 45W EXTENDS
A FRONT ALONG A 1016 HPA LOW AT 31S 41W...SOUTHERN SAO
PAULO/NORTHERN SANTA CATARINA-UPPER MESOPOTAMIA TO NORTHWEST
ARGENTINA. A RIDGE TO THE EAST CENTERS ON TWO HIGHS...A 1025 HPA
AT 38S 32W AND A 1025 HPA HIGH AT 30S 31W.
GUZMAN...SENAMHI (BOLIVIA)
URRA...DMC (CHILE)
DAVISON...HPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page