749
FXSA20 KWBC 121313
PMDSA
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
913 AM EDT TUE AUG 12 2008
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
SYNOPSIS (VALID FROM 00Z AUG 12). UPPER LEVEL ANALYSIS SHOWS A
DUAL BARRELED RIDGE OVER THE EASTERN PACIFIC AND NORTHERN SOUTH
AMERICA. AT 200 HPA A CLOSED CELL OF THE SUBTROPICAL RIDGE
CENTERS ON A HIGH NEAR 13S 90W. AN OPEN CELL EXTENDS WEST ALONG
10S 30W...07S 50W...TO WESTERN AMAZONIA BRASIL/NORTHERN JUNGLE OF
PERU. A COL ALONG 74W SEPARATES THESE RIDGES. THE RIDGE ALOFT IS
VENTING DEEP CONVECTION ACROSS AMAZONIA-PARA IN WESTERN
BRASIL...WITH CONVECTION BUILDING IN CLUSTERS.
THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS ALONG
69S 108W...67S 92W...EXITING AT 59S 86W. IT REFORMS AT 49S 90W...
ALONG 46S 76W...EXITING AT 40S 67W. IT REFORMS AT 40S 58W...
CROSSING A 145KT MAXIMUM AT 46S 44W...50S 25W...38S 16W...AND 38S
06W. THE NORTHERN POLAR HAS ITS ENTRANCE AT 47S 122W...ALONG 45S
109W...44S 38W...EXITING AT 36S 71W. IT REFORMS AT 32S
66W...CROSSING BUENOS AIRES/RIO DE LA PLATA...EXITING AT 38S 47W.
THE SUBTROPICAL JET LIES ALONG 23S 120W...28S 99W...30S 89W...26S
74W...EXITING AT 23S 55W. IT REFORMS AT 21S 43W...26S 28W...28S
15W...AND 30S 04W.
AT 500 HPA...A RIDGE ON THE SOUTHERN STREAM ORIGINATES ON A
CLOSED HIGH NEAR 42S 120W. NORTH OF THIS RIDGE...AN ELONGATED
NORTHERN STREAM TROUGH IS STRUNG ALONG CLOSED LOWS NEAR 34S
105W...32S 117W...AND 25S 125W. FARTHER EAST...UNDER THE
INFLUENCE OF THE SOUTHERN STREAM RIDGE...A SHORT WAVE TROUGH IS
SURGING NORTH ACROSS THE DRAKE PASSAGE...WHILE ANOTHER EXTENDS
FROM A LOW AT 53S 83W TO 50S 104W. A HIGH AMPLITUDE TROUGH
EXTENDS ALONG 60S 50W...50S 60W...LA PAMPA IN ARGENTINA TO 30S
70W. THE TROUGH IS FOCUSING ITS SHORT WAVE ENERGY ACROSS CENTRAL
PROVINCES IN ARGENTINA/BUENOS AIRES. A SKEWED RIDGE TO THE EAST
LIES ALONG 30S 30W...50S 25W...TO 60S 10W.
A RIDGE OVER THE PACIFIC CENTERS ON TWO 1039 HPA HIGHS...WITH ONE
NEAR 45S 120W AND THE OTHER AT 55S 111W. A TROUGH OVER THE
SOUTHERN CONE SUPPORTS A POLAR FRONT THAT EXTENDS FROM AN
OCCLUDED 988 HPA LOW AT 51S 84W...ALONG A 988 HPA LOW AT 55S
75W...PATAGONIA...PUERTO MONTT CHILE...A 1006 HPA LOW AT 45S
77W...TO 42S 90W. SCATTERED CLOUD COVER WITH EMBEDDED RAINFALL
WAS NOTED OVER SOUTHERN CHILE BETWEEN TEMUCO-PUERTO MONTT. A
RIDGE TO THE NORTH CENTERS ON TWO 1027 HPA HIGHS...ONE NEAR 33S
83W AND THE OTHER AT 36S 73W. AN ELONGATED FRONT TO THE EAST
ORIGINATES ON A 982 HPA LOW AT 57S 40W...ALONG A 1010 HPA TRIPLE
POINT LOW AT 50S 32W...45S 44W...A 1006 HPA LOW AT 42S 51W...RIO
DE LA PLATA-CORDOBA TO NORTHERN MENDOZA. THIS SYSTEM TRIGGERED A
SQUALL LINE OVER URUGUAY/LOWER MESOPOTAMIA VALLEY. A SECONDARY
FRONT EXTENDS ALONG A 1002 HPA LOW AT 45S 58W-SOUTHERN BUENOS
AIRES PROVINCE...TO 35S 65W. A BROAD RIDGE OVER THE CENTRAL
ATLANTIC CENTERS ON A 1039 HPA HIGH AT 38S 27W. AN ELONGATED
FRONT TO THE NORTH LIES ALONG 26S 24W...25S 32W...A 1022 HPA LOW
AT 27S 37W...SAO PAULO-MATO GROSSO DO SUL-SOUTHERN PARAGUAY TO
NORTHWEST ARGENTINA.
GUZMAN...SENAMHI (BOLIVIA)
URRA...DMC (CHILE)
DAVISON...HPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page