000 WTNT41 KNHC 212032 TCDAT1 HURRICANE IGOR DISCUSSION NUMBER 55 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010 500 PM AST TUE SEP 21 2010 LAND AND BUOY OBSERVATIONS IN NEWFOUNDLAND AND THE ADJACENT WATERS INDICATE THAT IGOR HAS BECOME FULLY EMBEDDED WITHIN A FRONTAL ZONE. JUST AFTER THE CENTER OF IGOR PASSED OVER CANADIAN BUOY 44251 NEAR CAPE RACE EARLIER IN THE DAY...THE TEMPERATURE DROPPED BY ABOUT 10 DEGREES F. HOWEVER...THE CYCLONE IS STILL PRODUCING HURRICANE- FORCE WINDS...AND THE INITIAL INTENSITY OF 70 KT IS BASED ON REPORTED SUSTAINED WINDS OF 63 KT AT BONAVISTA NEWFOUNDLAND. IGOR IS EXPECTED TO CONTINUE TO PRODUCE HURRICANE-FORCE WINDS FOR ANOTHER DAY OR SO...AND THEN SHOULD GRADUALLY WEAKEN AS IT MOVES NORTHWARD INTO THE DAVIS STRAITS. THE INITIAL MOTION IS ESTIMATED TO BE 25 DEGREES AT 34 KT. THE TRACK GUIDANCE CONTINUES TO BE IN RELATIVELY GOOD AGREEMENT IN SHOWING IGOR TURNING NORTHWESTWARD TO THE WEST OF GREENLAND IN A COUPLE OF DAYS AND INTERACTING WITH ANOTHER AREA OF LOW PRESSURE NEAR NORTHERN QUEBEC. THE MODELS DO SHOW VARYING SOLUTIONS... HOWEVER...ON WHICH OF THESE TWO SYSTEMS WILL BECOME THE DOMINANT ONE. THE OFFICIAL FORECAST...IN ACCORDANCE WITH GUIDANCE PROVIDED BY THE OCEAN PREDICTION CENTER...WILL KEEP IGOR AS A DISTINCT CYCLONE THROUGH 96 HOURS. THE OFFICIAL FORECAST INDICATES VERY LITTLE MOTION FROM 72 TO 96 HOURS SINCE THE CYCLONE WILL BE NORTH OF THE BELT OF STRONG WESTERLIES BY THEN. THE 12-FT SEAS RADII PROVIDED BY THE OCEAN PREDICTION CENTER ARE 480 NE...900 SE...1320 SW...AND 380 NW. RADII IN THE FORECAST/ADVISORY ARE LIMITED TO 995 N MI...BUT 12-FT SEAS ARE ACTUALLY OCCURRING AT A GREATER DISTANCE THAN THAT. FORECAST POSITIONS AND MAX WINDS INITIAL 21/2100Z 49.3N 51.7W 70 KT...POST-TROP/EXTRATROP 12HR VT 22/0600Z 53.0N 49.8W 70 KT...POST-TROP/EXTRATROP 24HR VT 22/1800Z 57.2N 51.0W 70 KT...POST-TROP/EXTRATROP 36HR VT 23/0600Z 61.6N 57.5W 55 KT...POST-TROP/EXTRATROP 48HR VT 23/1800Z 62.5N 60.5W 45 KT...POST-TROP/EXTRATROP 72HR VT 24/1800Z 62.0N 60.5W 40 KT...POST-TROP/EXTRATROP 96HR VT 25/1800Z 61.5N 59.5W 40 KT...POST-TROP/EXTRATROP 120HR VT 26/1800Z...DISSIPATED $$ FORECASTER BERG