251
FXSA20 KWBC 301312
PMDSA
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
911 AM EDT WED JUL 30 2008
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SYNOPSIS (VALID FROM 00Z JUL 30). AT 200 HPA...A CELL OF THE
SUBTROPICAL RIDGE DOMINATES THE FLOW PATTERN OVER NORTHERN SOUTH
AMERICA. IT CENTERS ON A CLOSED HIGH AT 08S 59W...WITH MEAN AXIS
WEST ALONG 08S ACROSS WESTERN BRASIL-NORTHERN PERU TO THE EASTERN
TROPICAL PACIFIC. THE SATELLITE IMAGERY CONTINUES TO SHOW
UNUSUALLY ACTIVE CONVECTION ACROSS PARA-AMAZONAS IN WESTERN
BRASIL TO THE NORTHERN JUNGLE OF PERU. FURTHERMORE...A SHORT WAVE
TROUGH EXTENDS ALONG 30S 30W...10S 37W...TO RIO GRANDE DO NORTE.
THIS IS ENHANCING COASTAL CONVECTION ACROSS NORTHEAST BRASIL.
THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS ALONG
62S 120W...60S 98W...52S 86W...48S 71W...EXITING AT 46S 56W. THE
NORTHERN POLAR LIES ALONG 36S 120W...42S 110W...43S 99W...42S
83W...EXITING AT 39S 68W. IT REFORMS AT 30S 59W...THEN ALONG 35S
50W...A 144KT MAXIMUM AT 36S 42W...30S 22W...AND A 146KT MAXIMUM
AT 31S 08W. THE SUBTROPICAL JET HAS ITS ENTRANCE AT 17S
88W...ALONG 17S 78W...A 137KT MAXIMUM AT 25S 63W...CIUDAD DEL
ESTE...EXITING AT 23S 45W. IT REFORMS AT 22S 25W...ALONG 26S
11W...AND 30S 05W.
AT 500 HPA...A LOW AMPLITUDE RIDGE EXTENDS OVER THE EASTERN
PACIFIC...WITH AXIS SOUTH ALONG 100W/105W TO 55S. EAST OF THIS
RIDGE...A CLOSED LOW NEAR 63S 65W ANCHORS A LOW AMPLITUDE TROUGH
ACROSS THE DRAKE PASSAGE TO THE SOUTHERN CONE. THE TROUGH IS
FOCUSING ITS SHORT WAVE ENERGY INTO EXTREME SOUTHERN CHILE/
PATAGONIA. FARTHER NORTH...A TROUGH EXTENDS ACROSS THE BUENOS
AIRES PROVINCE IN ARGENTINA...CORDOBA TO NORTHERN MENDOZA. A
SHORT WAVE TROUGH IS LAGGING OFF THE NORTHERN COAST OF
BRASIL...WITH AXIS EXTENDING NORTHWEST FROM A LOW NEAR 24S 74W TO
17S 87W. THE SOUTHERN AND NORTHERN STREAM PERTURBATIONS ARE
PUSHING EAST AGAINST A SKEWED RIDGE THAT EXTENDS ALONG 30S
47W...50S 40W...60S 30W...TO 70S 30W.
THE SURFACE ANALYSIS SHOWS A TROUGH ON THE SOUTHERN STREAM FLOW
WITH AN OCCLUDED 966 HPA LOW AT 63S 62W...WITH A FRONT ALONG 65S
75W...A 970 HPA LOW AT 61S 67W...A 982 HPA TRIPLE POINT LOW AT
57S 65W...52S 66W...TO 48S 71W. A SECONDARY FRONT CLOSELY
FOLLOWS...ORIGINATING ON A 974 HPA LOW AT 59S 76W...ALONG 55S
77W...TO 55S 86W. A RIDGE TO THE WEST CENTERS ON A 1017 HPA HIGH
AT 50S 98W. AN ELONGATED POLAR FRONT LIES TO THE NORTH...
ORIGINATING ON A 1010 HPA OCCLUDED LOW AT 44S 86W...THEN ALONG A
1010 HPA TRIPLE POINT LOW AT 42S 81W...40S 86W...AND 40S 94W.
FARTHER EAST...AN ELONGATED FRONT LIES ALONG A 986 HPA LOW AT 62S
51W...A 994 HPA LOW AT 59S 45W...57S 42W...A 1006 HPA LOW AT 53S
45W...49S 44W...A 1018 HPA LOW AT 44S 54W...TO THE BUENOS AIRES
PROVINCE. A SECONDARY FRONT LIES OVER PATAGONIA. OVER THE CENTRAL
ATLANTIC...MEANWHILE...A 1029 HPA HIGH AT 44S 33W ANCHORS A BROAD
RIDGE. NORTH OF THIS RIDGE...AN OCCLUDING 1014 HPA LOW AT 31S 29W
EXTENDS A FRONT ALONG 28S 32W...28S 39W...A 1014 HPA LOW AT 32S
52W...PARAGUAY TO SOUTHEAST BOLIVIA. THIS SYSTEM SUPPORTS
ORGANIZED DEEP CONVECTION OVER SOUTHERN BRASIL...WITH STRATIFORM
PRECIPITATION OVER URUGUAY.
COLMAN...DMH (PARAGUAY)
GUZMAN...SENAMHI (BOLIVIA)
DAVISON...HPC (USA)
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