THE WEATHER PREDICTION CENTER

CAMP SPRINGS, MD


SOUTH AMERICAN SYNOPSIS



 
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER CAMP SPRINGS MD
907 AM EDT TUE MAY 05 2009
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/
 
SYNOPSIS (VALID FROM 00Z MAY 05). THE SUBEQUATORIAL RIDGE IS
INITIALIZED OVER THE TROPICAL ATLANTIC WITH AXIS AT 200 HPA
EXTENDING WEST ALONG 05N TO THE GUIANAS. A SECONDARY CELL OF THIS
RIDGE EXTENDS FROM PANAMA/COSTA RICA TO COLOMBIA. THE SUBTROPICAL
RIDGE TO THE SOUTH EXTENDS WEST FROM A HIGH AT 07S 27W INTO
NORTHEAST BRASIL...WHILE A WEAKER CELL EXTENDS OVER PARA/AMAZONAS
IN WESTERN BRASIL. THE LATTER CENTERS ON A CLOSED HIGH AT 04S
60W. SATELLITE IMAGERY SHOWS TWO ARES OF DEEP CONVECTION...BOTH
TO THE NORTH OF 10S...WITH ONE TO THE EAST OF 53W AND THE OTHER
TO THE WEST OF 60W. CONVECTION OVER SOUTHEAST BRASIL ASSOCIATES
WITH AN UPPER LEVEL TROUGH THAT EXTENDS FROM A LOW AT 30S 45W TO
MATO GROSSO DO SUL. THIS FAVORS MODERATE...LOCALLY HEAVY...DEEP
CONVECTION OVER SAO PAULO.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR WITH AXIS ALONG
51S 120W...56S 98W...PUNTA ARENAS CHILE...EXITING AT 54S 54W. IT
REFORMS AT 54S 50W...ALONG 49S 37W...49S 22W...EXITING AT 47S
15W. THE NORTHERN POLAR LIES ALONG 45S 120W...A 165KT MAXIMUM AT
51S 108W...A 177KT MAXIMUM AT 53S 89W...A 184KT MAXIMUM AT 52S
67W...LAS MALVINAS...EXITING AT 43S 46W. IT REFORMS AT 41S
49W...ALONG A 126KT MAXIMUM AT 41S 40W...A 136KT MAXIMUM AT 44S
32W...39S 15W...EXITING AT 32S 10W. FURTHERMORE...THE NORTHERN
POLAR HAS A FINGER THAT ENVELOPS AN UPPER LOW OVER BUENOS AIRES
PROVINCE...EXTENDING FROM 40S 59W...ALONG 33S 65W...EXITING AT
39S 57W. THE SUBTROPICAL JET HAS ITS ENTRANCE AT 32S 89W...ALONG
26S 81W...28S 70W...EXITING AT 30S 60W. IT REFORMS AT 17S
45W...ALONG 23S 31W...A 136KT MAXIMUM AT 22S 17W...AND 21S 05W.

AT 500 HPA A RIDGE EXTENDS SOUTH ALONG 90W TO 45S. A TROUGH LIES
TO THE SOUTH...CENTERING ON A CLOSED LOW AT 66S 90W. A TIGHT BELT
OF MID/UPPER LATITUDE WESTERLIES SEPARATES THESE AXES...AS IT
DOMINATES AREA BETWEEN 46S-60S...WITH SHORT WAVE PERTURBATIONS
STREAMING ACROSS TIERRA DEL FUEGO-PATAGONIA. ON THE NORTHERN
STREAM...A LOW NEAR 37S 63W EXTENDS A TROUGH TO THE NORTHWEST
ACROSS LA SERENA CHILE TO THE PACIFIC NEAR 26S 88W. FARTHER
EAST...A SHORT WAVE TROUGH EXTENDS FROM A LOW AT 57S 37W...ALONG
45S 40W...TO 40S 50W. 

OVER THE EASTERN PACIFIC...A RIDGE ON THE NORTHERN STREAM CENTERS
ON A 1033 HPA HIGH AT 38S 92W. A TROUGH ON THE SOUTHERN STREAM
CENTERS ON A 942 HPA LOW AT 61S 66W...WITH A POLAR FRONT ALONG A
966 HPA LOW AT 55S 55W...50S 59W...48S 63W...A 994 HPA LOW AT 49S
69W...46S 74W...49S 89W...TO A 1018 HPA LOW AT 49S 101W. THIS
FAVORS LIGHT RAINFALL ACROSS TIERRA DEL FUEGO AND EXTREME
SOUTHERN CHILE. A WEAK FRONT TO THE NORTH LIES ALONG A 990 HPA
LOW AT 49S 53W...44S 57W...A 998 HPA LOW AT 46S 62W...TO NORTHERN
PATAGONIA/LA PAMPA IN ARGENTINA. LIGHT RAINFALL WAS NOTED ALONG
THE SOUTHERN COAST OF BUENOS AIRES PROVINCE/EASTERN LA PAMPA. AN
ELONGATED FRONT TO THE EAST AND NORTH ORIGINATES ON AN OCCLUDED
966 HPA LOW AT 55S 37W...A 986 HPA TRIPLE POINT LOW AT 48S 28W...
45S 30W...44S 34W...A 998 HPA LOW AT 43S 38W...39S 42W...38S
47W...A 1010 HPA LOW AT 38S 54W...URUGUAY-NORTHWEST
ARGENTINA...27S 71W...AND 23S 84W. LIGHT RAINFALL WAS NOTED OVER
NORTHWEST ARGENTINA. A RIDGE TO THE NORTH CENTERS ON TWO 1021 HPA
HIGHS...WITH ONE AT 26S 37W AND THE OTHER 32S 30W.

SEABRA...INMET (BRASIL)
VAZQUEZ...DINAC (PARAGUAY)
DAVISON...WPC (USA)




Last Updated: 907 AM EDT TUE MAY 05 2009