000 WTNT41 KNHC 191453 TCDAT1 HURRICANE IGOR DISCUSSION NUMBER 46 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010 1100 AM AST SUN SEP 19 2010 SATELLITE AND MICROWAVE IMAGERY SHOWS THAT THE ORGANIZATION OF IGOR HAS CHANGED LITTLE SINCE THE RECONNAISSANCE AIRCRAFT DEPARTED THE HURRICANE THIS MORNING. THEREFORE...THE INITIAL INTENSITY WILL REMAIN 75 KT...BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES. DRIFTING BUOY 44903...RECENTLY REPORTED A PRESSURE OF 951 MB...WHICH SUGGESTS THAT THERE HAS BEEN LITTLE CHANGE TO THE MINIMUM PRESSURE THAT WAS REPORTED EARLIER BY THE AIRCRAFT. THE NEXT RECONNAISSANCE AIRCRAFT IS SCHEDULED TO REACH THE HURRICANE AROUND 1800 UTC THIS AFTERNOON. IGOR HAS TURNED NORTHWARD AND IS MOVING A LITTLE FASTER THAN BEFORE...WITH AN INITIAL MOTION OF 360/12. THE HURRICANE IS FORECAST TO CONTINUE NORTHWARD FOR THE NEXT 12 HOURS OR SO...THEN TURN NORTHEASTWARD AND ACCELERATE AHEAD OF A MID-LATITUDE TROUGH MOVING OFF THE COAST OF NORTH AMERICA. THE OFFICIAL FORECAST TRACK IS VERY CLOSE TO THE PREVIOUS ADVISORY DURING THE FIRST 36 HOURS AND LIES JUST EAST OF THE MULTI-MODEL CONSENSUS. THE MODELS ARE IN RELATIVELY GOOD AGREEMENT SHOWING THE SYSTEM PASSING NEAR OR JUST SOUTHEAST OF NEWFOUNDLAND IN 2-3 DAYS. THEREAFTER...THE SPREAD IN THE TRACK GUIDANCE INCREASES SIGNIFICANTLY. AT THE LONGER RANGE...THE NEW NHC TRACK FORECAST IS CLOSE THE CONSENSUS AND IS IN BEST AGREEMENT WITH THE GFS AND UKMET SOLUTIONS. IGOR WILL REMAIN A LARGE HURRICANE AS IT PASSES BERMUDA...AND LITTLE CHANGE IN INTENSITY IS FORECAST WHILE IGOR REMAINS A TROPICAL CYCLONE. EXTRATROPICAL TRANSITION SHOULD BEGIN IN ABOUT A DAY AND SHOULD BE COMPLETE IN ABOUT 48 HOURS. AFTER 72 HOURS...GRADUAL WEAKENING IS INDICATED BY THE GLOBAL MODELS AND THIS IS FOLLOWED IN THE OFFICIAL FORECAST. SUSTAINED TROPICAL STORM FORCE WINDS HAVE BEEN OBSERVED AT THE OFFICIAL OBSERVING SITE IN BERMUDA...WITH WIND GUSTS TO NEAR HURRICANE FORCE ALREADY REPORTED. THE 34-KT WIND RADII WAS EXPENDED OVER THE NORTHWEST QUADRANT BASED ON DATA FROM NOAA BUOY 41048. FORECAST POSITIONS AND MAX WINDS INITIAL 19/1500Z 30.4N 65.4W 75 KT 12HR VT 20/0000Z 32.3N 65.2W 75 KT 24HR VT 20/1200Z 35.4N 63.9W 75 KT 36HR VT 21/0000Z 39.3N 60.5W 75 KT 48HR VT 21/1200Z 43.5N 55.0W 70 KT...POST-TROP/EXTRATROP 72HR VT 22/1200Z 50.5N 45.5W 65 KT...POST-TROP/EXTRATROP 96HR VT 23/1200Z 54.5N 40.5W 45 KT...POST-TROP/EXTRATROP 120HR VT 24/1200Z 59.0N 39.0W 35 KT...POST-TROP/EXTRATROP $$ FORECASTER BROWN