000
WTNT41 KNHC 200235
TCDAT1
HURRICANE IGOR DISCUSSION NUMBER  48
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112010
1100 PM AST SUN SEP 19 2010
 
THE LAST OBSERVATIONS FROM THE AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT SHOWED THAT THE CENTRAL PRESSURE WAS SLOWLY RISING AND
MAXIMUM FLIGHT LEVEL WINDS HAD DECREASED TO 68 KT.  THERE WERE A
FEW SFMR-OBSERVED SURFACE WINDS OF 65 TO 69 KT ABOUT 90 N MI TO THE
SOUTHWEST OF THE CENTER BUT MOST OF THESE WERE FLAGGED AS
QUESTIONABLE.  THE CURRENT INTENSITY IS SET AT 65 KT...WHICH IS
REMARKABLY LOW FOR THE ESTIMATED CENTRAL PRESSURE OF 955 MB.  NOT
MUCH ADDITIONAL WEAKENING IS ANTICIPATED OVER THE NEXT DAY OR SO. 
BY 36 HOURS...THE GFS SHOWS WELL-DEFINED THERMAL ADVECTION WITHIN
THE CIRCULATION AND THEREFORE IGOR IS LIKELY TO HAVE BEEN
TRANSFORMED INTO A VIGOROUS EXTRATROPICAL CYCLONE AROUND THAT TIME.

THE LATEST CENTER FIXES INDICATE THAT THE TRACK IS BEGINNING TO
BEND TO THE RIGHT AND THE INITIAL MOTION IS ESTIMATED TO BE 015/12. 
NOT MUCH CHANGE IS MADE TO THE OFFICIAL FORECAST TRACK FOR THE NEXT
24 TO 36 HOURS.  IGOR IS EXPECTED TO TURN NORTHEASTWARD ON MONDAY
AND ACCELERATE AHEAD OF A DEEP-LAYER TROUGH MOVING EASTWARD FROM
THE NORTHEASTERN U.S. AND THE CANADIAN MARITIMES. IN THE LATTER HALF
OF THE FORECAST PERIOD...POST-TROPICAL IGOR IS LIKELY TO TURN BACK
TO THE NORTH AND NORTH-NORTHWEST AS IT INTERACTS WITH ANOTHER
EXTRATROPICAL CYCLONE AT HIGH LATITUDES.

SUSTAINED WINDS OF 64 KT WITH GUSTS TO 81 KT WERE REPORTED AT
BERMUDA DURING THE PAST HOUR.  SINCE IGOR HAS A VERY LARGE
CIRCULATION...SIGNIFICANT IMPACTS ON THE ISLAND WILL PROBABLY
CONTINUE THROUGH THE NIGHT. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0300Z 32.4N  65.5W    65 KT
 12HR VT     20/1200Z 34.6N  64.4W    65 KT
 24HR VT     21/0000Z 38.1N  60.9W    65 KT
 36HR VT     21/1200Z 42.5N  55.5W    70 KT...POST-TROP/EXTRATROP
 48HR VT     22/0000Z 46.5N  49.0W    70 KT...POST-TROP/EXTRATROP
 72HR VT     23/0000Z 49.5N  38.0W    50 KT...POST-TROP/EXTRATROP
 96HR VT     24/0000Z 58.0N  37.0W    40 KT...POST-TROP/EXTRATROP
120HR VT     25/0000Z 62.0N  42.0W    30 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER PASCH