895  
FXSA20 KWBC 061348  
PMDSA  
 
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
847 AM EST TUE FEB 06 2018  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/  
 
SYNOPSIS (VALID FROM FEB 06 AT 0000 UTC): AT 200 HPA...THE  
SUBTROPICAL RIDGE/BOLIVIAN HIGH IS MEANDERING WESTWARD WHILE  
CENTERING OVER ANTOFAGASTA IN CHILE. THE HIGH IS VENTILATING DEEP  
CONVECTION ALONG THE ANDES FROM CENTRAL CHILE/CENTRAL ARGENTINA  
INTO CENTRAL PERU. A DEEP AND LONG-WAVE TROUGH EXTENDS TO THE EAST  
OF THE RIDGE...ALONG SANTA CATARINA/PARANA...MATO GROSSO DO SUL  
AND NORTHWESTERN MATO GROSSO IN BRASIL. THIS UPPER TROUGH IS STILL  
SUSTAINING THE PRESENCE OF A WEAKENING SOUTH ATLANTIC CONVERGENCE  
ZONE AND VENTILATING STRONG CONVECTION. THE SACZ EXTENDS ALONG  
MINAS GERAIS...NORTHERN MATO GROSSO...CENTRAL  
AMAZONAS...CENTRAL/NORTHERN PERU. ACTIVE DIURNAL CONVECTION IS  
ALSO OCCURRING IN THE INTERIOR OF THE BRAZILIAN NORDESTE...WHERE  
DEEP-LAYER INSTABILITY STRETCHES FROM BAHIA INTO CEARA.  
 
AT 250 HPA...THE SOUTHERN POLAR LIES ALONG 56S 119W...A 145KT  
MAXIMUM AT 53S 116W...50S 106W...A 146KT MAXIMUM AT 56S 84W...62S  
60W...56S 47W...58S 20W...A 153KT MAXIMUM AT 55S 11W...AND 49S  
02W. THE NORTHERN POLAR LIES ALONG 47S 120W...A 148KT MAXIMUM AT  
49S 101W...52S 87W...A 147KT MAXIMUM AT 55S 75W...55S  
61W...EXITING AT 52S 54W. IT REFORMS AT 51S 47W...ALONG 53S  
27W...A 146KT MAXIMUM AT 48S 09W...AND 48S 02W. A FINGER OF THE  
NORTHERN POLAR LIES TO THE NORTH...WITH ENTRANCE AT 44S  
85W...ALONG 40S 82W...EXITING AT 45S 79W. THE SUBTROPICAL JET HAS  
ITS ENTRANCE AT 36S 81W...ALONG 41S 69W...38S 58W...31S  
56W...EXITING AT 20S 58W. IT REFORMS AT 20S 47W...ALONG 28S  
40W...35S 30W...34S 18W...AND 34S 01W. AT 200 HPA...THE  
SUBEQUATORIAL JET HAS A FINGER THAT EXTENDS ALONG 04N 104W...05N  
100W...EXITING AT 05N 95W. AT 150 HPA...A FINGER TO THE SOUTH  
EXTENDS ALONG 06S 113W...06S 105W...09S 95W...EXITING AT 13S 87W.  
 
AT 500 HPA...BROAD TROUGH EXTENDS OVER THE SOUTHEAST  
PACIFIC/BELLINGSHAUSEN SEA...WITH AXIS ANCHORING ON A CLOSED LOW  
NEAR 65S 93W. A SHORT WAVE TROUGH TO THE NORTH IS STREAMING  
TOWARDS SOUTHERN CHILE WHILE CENTERING ON A CLOSED LOW AT 44S 83W.  
THESE ARE PRESSING AGAINST A SKEWED RIDGE TO THE EAST THAT EXTENDS  
FROM NORTHWEST ARGENTINA...ACROSS PATAGONIA-DRAKE PASSAGE TO THE  
ANTARCTIC PENINSULA. EAST OF THIS RIDGE...A SHORT WAVE TROUGH ON  
THE SOUTHERN STREAM EXTENDS BETWEEN 50W-25W AND TO THE SOUTH OF  
50S. A SHORT WAVE TROUGH TO THE NORTH TRAILS THIS AXIS...CENTERING  
ON A CYCLONIC MAXIMA AT 45S 47W. FARTHER NORTH...A LOW AMPLITUDE  
TROUGH EXTENDS ACROSS SOUTHEAST BRASIL TO MATO GROSSO.  
 
AT LOW LEVELS...BROAD TROUGH ON THE SOUTHEAST PACIFIC CENTERS ON  
AN OCCLUDED 942 HPA LOW AT 63S 93W. THIS EXTENDS A FRONT ALONG A  
962 HPA LOW AT 65S 75W...60S 69W...57S 72W...53S 80W...A 986 HPA  
LOW AT 52S 86W...45S 94W...AND 42S 109W. ANOTHER FRONT TO THE  
NORTH AND EAST EXTENDS FROM AN OCCLUDED 970 HPA LOW AT 59S 29W...A  
970 HPA LOW AT 57S 24W...49S 29W...47S 43W...A 1002 HPA LOW AT 48S  
50W...44S 55W...45S 62W...A 1002 HPA LOW AT 49S 70W...46S  
71W...46S 74W...A 1002 HPA LOW AT 44S 81W...39S 78W...32S  
86W...31S 96W...TO A 1008 HPA LOW AT 33S 100W. ALSO OVER THE  
ATLANTIC...A RIDGE ON THE NORTHERN STREAM CENTERS ON A 1017 HPA  
HIGH AT 36S 41W. AN OLD FRONT TO THE NORTH LIES ALONG A 1014 HPA  
LOW AT 32S 11W...31S 15W...32S 21W...A 1014 HPA LOW AT 34S  
27W...31S 29W...30S 33W...TO 26S 46W.  
 
BALBINO...INMET (BRASIL)  
POMIER...SENAMHI (BOLIVIA)  
DAVISON/GALVEZ...WPC (USA)  

 
 
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