THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


SOUTH AMERICAN SYNOPSIS




SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
927 AM EDT THU MAR 23 2017

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SYNOPSIS (VALID FROM MARCH 23 AT 0000 UTC): AT 200 HPA...THE
SUBTROPICAL HIGH WAS LOCATED OVER MATO GROSSO IN BRASIL. THE HIGH
ANCHORS A RIDGE OVER THE CONTINENT TO THE NORTH OF 30S AND WEST OF
40W. EAST OF THIS AXIS...A TROUGH EXTENDS NORTH ALONG 37W/38W TO
00N. THE TROUGH IS ENHANCING CONVECTION ALONG THE NORTH COAST OF
BRASIL...WHILE THE RIDGE VENTS DIURNAL CONVECTION ACROSS
CENTRAL-WESTERN BRASIL-BOLIVIA AND PERU. MOST ACTIVE CONVECTION
CLUSTERED ON THE NORTH COAST OF PERU AS ENHANCED BY THE EASTERN
PACIFIC ITCZ.

AT 250 HPA...THE SOUTHERN POLAR HAS ITS ENTRANCE AT 64S 69W...THEN
ALONG 54S 49W...53S 42W...EXITING AT 56S 33W. THE NORTHERN POLAR
LIES ALONG 44S 120W...A 120KT MAXIMUM AT 47S 112W...51S 98W...50S
82W...53S 66W...EXITING AT 49S 53W. THE SUBTROPICAL JET HAS ITS
ENTRANCE AT 22S 90W...THEN ALONG 23S 84W...27S 77W...28S 65W...29S
56W...29S 48W...EXITING AT 24S 37W.

AT 500 HPA...IN A TIGHT BELT OF MID LATITUDE WESTERLIES...AN
AMPLIFYING TROUGH EXTENDS ALONG 118W/120W TO 40S. A SHORT WAVE
RIDGE ALONG 95W SEPARATES THE LATTER FROM A SHORT WAVE TROUGH OFF
THE SOUTH COAST OF CHILE. FARTHER EAST...ANOTHER SHORT WAVE TROUGH
ON THE SOUTHERN STREAM FLOW EXTENDS ALONG 44W/45W TO 45S. SHORT
WAVE PERTURBATIONS ALSO POPULATE THE NORTHERN STREAM FLOW...WITH
ONE OFF THE CENTRAL COAST OF CHILE FOCUSING SHORT WAVE ENERGY
ACROSS CENTRAL/NORTHERN PROVINCES OF ARGENTINA. THESE PROVIDE THE
DYNAMICAL SUPPORT TO CONVECTIVE DEVELOPMENT ACROSS MID SECTIONS OF
SOUTH AMERICA. ANOTHER OVER THE ATLANTIC EXTENDS BETWEEN 35W-25W
TO 20S.

AT LOW LEVELS...BROAD RIDGE ON THE NORTHERN STREAM OVER THE
EASTERN PACIFIC ANCHORS ON TWO 1023 HPA HIGHS...WITH ONE AT 30S
108W AND THE OTHER AT 38S 89W. PROGRESSIVE FRONT TO THE SOUTH
EXTENDS FROM AN OCCLUDED 986 HPA LOW AT 58S 85W...THEN ALONG A 994
HPA LOW AT 58S 74W...54S 70W...52S 72W...50S 74W...A 1014 HPA LOW
AT 49S 81W...43S 84W...41S 94W...A 1010 HPA LOW AT 45S 104W...41S
103W...AND 39S 111W. FARTHER EAST...OVER THE SOUTH ATLANTIC...AN
OCCLUDING 982 HPA LOW AT 61S 42W EXTENDS A FRONT ALONG 55S
39W...51S 44W...A 1014 HPA LOW AT 49S 49W...46S 53W...TO 47S 60W.
AN ELONGATED FRONT TO THE NORTH LIES ALONG A 1014 HPA LOW AT 49S
35W...46S 36W...44S 40W...A 1014 HPA LOW AT 47S 46W...43S
51W...43S 58W...TO NORTHERN PATAGONIA IN ARGENTINA. A RIDGE TO THE
NORTH...CENTERS ON TWO HIGHS...A 1025 HPA AT 39S 37W AND A 1027
HPA AT 42S 13W. NORTH OF THIS RIDGE...AN OCCLUDING 1006 HPA LOW AT
32S 25W EXTENDS A FRONT ALONG A 1008 HPA LOW AT 33S 24W...THEN
ALONG 30S 22W...28S 23W...A 1010 HPA LOW AT 26S 25W...19S
29W....15S 38W...MINAS GERAIS TO CHACO PARAGUAYO. DEEP CONVECTION
WAS BUILDING TO THE NORTH OF THIS FEATURE. A PREFRONTAL SHEAR
EXTENDS ACROSS NORTHERN BAHIA...FAVORING SCATTERED COASTAL
CONVECTION.

ABDEMUR...FAA (ARGENTINA)
TEPES...DMC (CHILE)
GALVEZ/DAVISON...WPC (USA)




Last Updated: 927 AM EDT THU MAR 23 2017