588  
FXSA20 KWBC 071453  
PMDSA  
 
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
952 AM EST WED FEB 07 2018  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/  
 
SYNOPSIS (VALID FROM FEB 07 AT 0000 UTC): AT 200 HPA...THE  
BOLIVIAN HIGH/SUBTROPICAL RIDGE CENTERS OVER EXTREME NORTHERN  
CHILE...AND EXTENDS FROM 80W TO 60-62W AND SOUTH TO LA SERENA IN  
CHILE. THE HIGH IS VENTILATING CONVECTION MOSTLY ALONG THE  
ALTIPLANO...WHERE CONVECTIVE INSTABILITY AND MOISTURE AVAILABILITY  
REMAIN HIGH. TO THE EAST...A LARGE AND ELONGATED TROUGH EXTENDS  
FROM PARANA/SAO PAULO IN BRASIL NORTH ACROSS MATO GROSSO INTO  
WESTERN PARA. THIS TROUGH IS INTERACTING WITH THE WEAKENING SOUTH  
ATLANTIC CONVERGENCE ZONE...AND WITH A POOL OF CONVECTIVE  
INSTABILITY IN THE INTERIOR OF THE BRAZILIAN NORDESTE...WHERE  
ORGANIZED DEEP CONVECTION IS OCCURRING. LESS ORGANIZED CONVECTION  
IS OCCURRING ALONG THE NET...WHICH EXTENDS ALONG 10S-05W FROM  
NORTHERN MATO GROSSO INTO NORTHERN PERU.  
 
THE UPPER JET ANALYSIS SHOWS THE SOUTHERN POLAR FORMING AT 44S  
115W ALONG A 136KT MAXIMA AT 46S 104W...47S 91W...A 154KT MAXIMA  
AT 49S 83W...55S 71W...A 148KT MAXIMA AT 63S 59W...64S 43W...A  
142KT MAXIMA AT 60S 32W...EXITING AT 49S 26W. THE NORTHERN POLAR  
JET FORMS AT 41S 120W ALONG 43S 103W...45S 86W...51S 69W...A 125KT  
MAXIMA AT 58S 58W...59S 41W...44S 33W. ANOTHER BRANCH FORMS AT 49S  
64W ALONG 53S 59W...EXITING AT 54S 49W. THE SUBTROPICAL JET FORMS  
AT 178S 49W ALONG 23S 43W...32S 37W...A 132KT MAXIMA AT 36S  
28W...36S 18W...35S 08W.  
 
AT 500 HPA...A LARGE AND DEEP TROUGH IS LOCATED OVER THE  
BELLINGSHAUSEN SEA/EASTERN PACIFIC...CENTERING ON A LOW AT 64S  
82W. THE TROUGH EXTENDS TO THE NORTH INTO 50S...WHERE A TIGHT BELT  
OF WEST-NORTHWESTERLY WINDS LIES. TO THE EAST...A RIDGE EXTENDS IN  
THE SOUTH ATLANTIC ALONG 50W-30W AND TO THE SOUTH OF 40S. A SHORT  
WAVE TROUGH LIES TO THE WEST OF THIS RIDGE WHILE EXITING CENTRAL  
PATAGONIA. IN THE NORTHERN STREAM...A HIGH CENTERS OVER THE  
EASTERN PACIFIC AT 26S 85W...AND EXTENDS A RIDGE INTO LA SERENA IN  
CHILE...AND THE BUENOS AIRES PROVINCE IN ARGENTINA. A BROAD BUT  
ILL-DEFINED TROUGH LIES TO THE EAST...EXTENDING OVER MOST OF  
SOUTHERN BRASIL.  
 
AT LOW LEVELS...A FRONT EXTENDS ALONG 57S 56W...A 986 HPA LOW AT  
55S 65W...52S 63W...50S 68W... A 994 HPA LOW AT 47S 78W...47S  
76...A 1006 HPA LOW AT 47S 79W...44S 79W. A FRONT EXTENDS ALONG A  
994 HPA LOW AT 49S 64W...46S 61W...A 998 HPA LOW AT 43S 62W...40S  
62W...A 1002 HPA LOW AT 36S 66W...33S 69W. THUNDERSTORMS WERE  
OCCURRING IN THE WARM SIDE OF THIS BOUNDARY ACROSS LA PAMPA/SAN  
LUIS AND THE SOUTHERN BUENOS AIRES PROVINCE. OVER THE PACIFIC...A  
1021 HPA HIGH CENTERS AT 34S 83W. A 1017 HPA HIGH CENTERS AT 50S  
42W OVER THE SOUTH ATLANTIC. TO THE NORTH...A WEAKENING SOUTH  
ATLANTIC CONVERGENCE ZONE EXTENDS FROM 27S 36W ALONG 18S 63W...12S  
51W...06S 60W.  
 
POMIER...SENAMHI (BOLIVIA)  
BALBINO...INMET (BRASIL)  
GALVEZ...WPC (USA)  

 
 
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