793
FXSA20 KWBC 151307
PMDSA
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
906 AM EDT FRI AUG 15 2008
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SYNOPSIS (VALID FROM 00Z AUG 15). AT 200 HPA...A CELL OF THE
SUBTROPICAL RIDGE REMAINS OVER THE EASTERN PACIFIC...DOMINATING
AREA NORTH OF 25S AND WEST OF 70W...WITH A CLOSED HIGH NEAR 35S
90W. ANOTHER CELL EXTENDS ACROSS NORTHERN SOUTH AMERICA...WITH
MEAN AXIS WEST ALONG 08S/10S TO 70W. EXCEPT FOR WIDELY ISOLATED
CONVECTION OVER NORTHERN PERU-ECUADOR...ORGANIZED TROPICAL
CONVECTION NOW CONFINES TO NORTH OF THE EQUATOR ACROSS THE
GUIANAS-VENEZUELA AND COLOMBIA.
THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS ALONG
67S 109W...59S 97W...53S 78W...A 137KT MAXIMUM AT 55S 48W...57S
29W...AND 54S 09W. THE NORTHERN POLAR HAS A FINGER WITH AXIS
ALONG 57S 120W...A 145KT MAXIMUM AT 57S 102W...EXITING AT 50S
94W. THE NORTHERN POLAR REFORMS FARTHER NORTH WITH AXIS ALONG 30S
120W...34S 99W...EXITING NEAR 41S 73W. IT REFORMS BETWEEN 44S 74W
AND 45S 54W. THE NORTHERN POLAR REFORMS AGAIN FARTHER EAST NEAR
41S 38W...ALONG 40S 30W...44S 19W...AND A 143KT MAXIMUM AT 44S
08W. THE SUBTROPICAL JET LIES ALONG 24S 120W...A 140KT MAXIMUM AT
29S 100W...30S 80W...EXITING AT 23S 61W. IT REFORMS BETWEEN 23S
50W AND 27S 40W. THE SUBTROPICAL JET HAS ANOTHER FINGER WITH
ENTRANCE AT 31S 37W...CROSSING 37S 26W...AND 38S 10W.
AT 500 HPA...A RIDGE EXTENDS SOUTH FROM A HIGH NEAR 44S 115W TO
60S 120W. UNDER THE INFLUENCE OF THIS RIDGE THE SOUTHERN STREAM
IS SURGING ACROSS THE ANTARCTIC PENINSULA TO THE DRAKE PASSAGE/
TIERRA DEL FUEGO. ON THE NORTHERN STREAM...MEANWHILE...A LOW NEAR
44S 83W EXTENDS A TROUGH ALONG 37S 90W...35S 100W...TO 34S 110W.
THIS TROUGH IS FOCUSING ITS SHORT WAVE ENERGY ACROSS CENTRAL AND
SOUTHERN CHILE. OTHER NORTHERN STREAM VORTICES ARE MOVING ACROSS
NORTHWEST PROVINCES OF ARGENTINA-PARAGUAY-SOUTHERN BRASIL.
RIDGING TO THE NORTH PERSIST ACROSS CENTRAL AND NORTHERN BRASIL
TO MOST OF BOLIVIA/SOUTHERN PERU...SUSTAINING A SUBSIDENCE
INVERSION WHILE ALSO INHIBITING ORGANIZED CONVECTION.
AT LOW LEVELS...A RIDGE OVER THE SOUTH PACIFIC CENTERS ON A 1037
HPA HIGH AT 43S 115W. A BROAD TROUGH ON THE SOUTHERN STREAM
DOMINATES THE FLOW ACROSS THE ANTARCTIC PENINSULA TO TIERRA DEL
FUEGO IN SOUTHERN CHILE. FRONTS ARE REVOLVING AROUND THIS
AXIS...WITH ONE THAT EXTENDS FROM A 950 HPA LOW AT 65S
38W...ALONG A 962 HPA TRIPLE POINT LOW AT 61S 30W...SOUTH GEORGIA
ISLANDS...54S 51W...A 976 HPA LOW AT 55S 62W...52S 80W...AND 53S
101W. THIS FAVORS LIGHT SNOWFALL OVER EXTREME SOUTHERN CHILE/
ARGENTINA. NORTH OF THIS AXIS...A 994 HPA LOW AT 49S 69W EXTENDS
A FRONT NORTH ALONG THE COAST OF PATAGONIA...THEN SOUTHERN CUYO
NEAR 38S 69W...A 1002 HPA LOW AT 40S 75W...35S 78W...A 1006 HPA
LOW AT 35S 84W...AND 27S 95W. AN OCCLUDED 992 HPA LOW AT 43S 82W
ANCHORS A TROUGH OFF THE SOUTHERN COAST OF CHILE. THESE SYSTEMS
COMBINE IN SUPPORT OF ORGANIZED HEAVY RAINFALL ACROSS SOUTHERN
AND CENTRAL PORTIONS OF CHILE. ON THE NORTHERN STREAM...AN
ELONGATED FRONT LIES ALONG 38S 20W...33S 32W...A 1022 HPA LOW AT
30S 40W...SAO PAULO...A 1014 HPA LOW OVER SOUTHERN PARAGUAY TO
EASTERN BOLIVIA. SCATTERED DEEP CONVECTION WAS BUILDING OVER
SOUTHERN BRASIL.
GUZMAN...SENAMHI (BOLIVIA)
URRA...DMC (CHILE)
DAVISON...HPC (USA)
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