343  
FXSA20 KWBC 081430  
PMDSA  
 
SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
930 AM EST FRI DEC 08 2017  
 
GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/  
 
SYNOPSIS (VALID FROM DEC 08 AT 0000 UTC): AT 200 HPA...A ROBUST  
SUBTROPICAL RIDGE/BOLIVIAN HIGH CENTERS OVER MATO GROSSO IN  
BRASIL. THE HIGH IS VENTILATING CONVECTION ACROSS MOST OF TROPICAL  
SOUTH AMERICA...BUT ESPECIALLY IN EASTERN BRASIL...WHERE  
DEEP-LAYER INSTABILITY REMAINS IN PLACE. STRONGEST CONVECTION IS  
ORGANIZING IN ASSOCIATION WITH LOW-LEVEL TROUGHS ACROSS  
CENTRAL/EASTERN BRASIL...AND INTO MATO GROSSO DO SUL/PANTANAL.  
ALSO...SHORT-LIVED DIURNAL CONVECTION IS OCCURRING IN THE PERUVIAN  
AND BOLIVIAN ANDES.  
 
THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET EXTENDING  
ALONG 56S 120W...57S 99W...EXITING AT 59S 90W. IT REFORMS AT 61S  
80W...EXITING AT 50S 58W...IT REFORMS AT 49S 51W...ALONG 50S 27W.  
THE NORTHERN POLAR JET EXTENDS ALONG 54S 120W...A 179KT MAXIMA AT  
54S 117W...52S 104W...51S 90W...EXITING AT 47S 85W. IT REFORMS AT  
43S 76W...EXITING AT 39S 49W. THE SUBTROPICAL JET EXTENDS ALONG  
50S 120W...48S 93W...EXITING AT 40S 88W. IT REFORMS AT 27S 75W  
ALONG 31S 61W...25S 39W...23S 21W. THE SUBEQUATORIAL JET EXTENDS  
ALONG07S 113W...05S 97W...EXITING AT 00 90W.  
 
AT 500 HPA...THE SOUTHERN STREAM IS CHARACTERIZED BY A BROAD  
TROUGH WITH SEVERAL WEAK LOWS PROPAGATING FROM WEST TO EAST. ONE  
EXTENDS ALONG 110W AND TO THE SOUTH OF55S...A RIDGE FOLLOWS AHEAD  
ALONG 80-85W...AND ANOTHER TROUGH IS EXITING THE SOUTHERN CONE  
ALONG 60-65W. A TIGHT BELT OF WESTERLIES EXTENDS TO THE NORTH  
ALONG60S-50W. IN THE NORTHERN STREAM...A BROAD WEAK LOW EXTENDS  
OFF THE COAST OF CHILE CENTERING AT 28S 90W. OVER THE  
CONTINENT...A BROAD RIDGE EXTENDS FROM THE ALTIPLANO SOUTH ALONG  
70-68W...AND TO THE EAST...A BROAD TROUGH EXTENDS AN AXIS FROM 35S  
44W INTO THE RIO DE JANEIRO AREA.  
 
AT LOW LEVELS...A 958 HPA OCCLUDED LOW CENTERS AT 64S 109W...AND  
EXTENDS AN OCCLUDED FRONT INTO A 968 HPA TRIPLE POINT LOW AT 76S  
94W...63S 93W...A 978 HPA LOW AT 60S 94W...53S 97W...49S 106W. A  
982 HPA OCCLUDED LOW CENTERS AT 64S 69W AND EXTENDS A FRONT TO A  
984 HPA TRIPLE POINT LOW AT 63S 64W...59S 62W...56S 63W. A 998 HPA  
OCCLUDED LOW CENTERS AT 52S 60W AND EXTENDS A FRONT INTO A 1000  
HPA TRIPLE POINT LOW AT 53S 58W...49S 58W...47S 62W...A 1002 HPA  
LOW AT 47S 67W...41S 67W...AND A WEAKENING FRONT ALONG39S  
73W...38S 87W. A 1031 HPA HIGH CENTERS AT 37S 106W. A 1006 HPA LOW  
AT 35S 45W EXTENDS A FRONT ALONG 33S 44W...30S 50W...29S 55W.  
ISOLATED THUNDERSTORMS WERE OCCURRING IN INTERIOR PORTIONS OF  
CENTRAL ARGENTINA IN ASSOCIATION WITH A WEAK UPPER TROUGH CROSSING  
THE ANDES.  
 
OVIEDO...SHN (ARGENTINA)  
POMIER...SENAMHI (BOLIVIA)  
RIVAS...SENAMHI (PERU)  
GALVEZ...WPC (USA)  

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page