000 WTNT43 KNHC 150836 TCDAT3 TROPICAL STORM INGRID DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082007 500 AM EDT SAT SEP 15 2007 IT HAS BEEN A CHALLENGE LOCATING THE LOW-LEVEL CIRCULATION OF INGRID EARLY THIS MORNING. BELLIGERENT SOUTHWESTERLY SHEAR IS TAKING A TOLL ON INGRID AND THE REMAINING DEEP CONVECTION IS CONFINED TO THE SOUTHEASTERN QUADRANT FROM THE ESTIMATED CENTER. DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB REMAIN AT 35 KT AND SO WILL THE INITIAL INTENSITY. ANOTHER NOAA HURRICANE HUNTER AIRCRAFT WILL BE BACK INVESTIGATING THE CYCLONE AROUND 12Z...AND A MORE ACCURATE MEASUREMENT WILL BE TAKEN. INGRID IS EXPECTED TO REMAIN IN A STRONGLY SHEARED ENVIRONMENT AT LEAST FOR THE NEXT 48 HOURS. THESE UPPER-LEVEL WINDS SHOULD INHIBIT ANY STRENGTHENING AND COULD POSSIBLY CAUSE DISSIPATION OF THE CYCLONE. HOWEVER...AFTER 3 DAYS OR SO THE SHEAR IS FORECAST TO RELAX AND IF INGRID SURVIVES THAT LONG SOME OF THE INTENSITY GUIDANCE INDICATES THAT RESTRENGTHENING COULD OCCUR. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS FORECAST AND MAINTAINS INGRID AS A MINIMAL TROPICAL CYCLONE THROUGH FIVE DAYS. THE INITIAL MOTION IS ESTIMATED AT 295/9. A GENERAL MOTION TO THE WEST-NORTHWEST TO NORTHWEST SHOULD CONTINUE FOR THE NEXT 24-48 HOURS. THEREAFTER...A TURN MORE TOWARD THE NORTH-NORTHWEST WITH A SLIGHT DECREASE IN FORWARD MOTION IS ANTICIPATED AS INGRID...OR THE REMNANT LOW OF INGRID...RESPONDS TO A MID-LEVEL TROUGH TO ITS NORTH. THE MODEL GUIDANCE IS IN CLOSE AGREEMENT...BUT HAS SHIFTED A BIT MORE TO THE EAST THAN THE PREVIOUS CYCLE. THE OFFICIAL TRACK FORECAST FOLLOWS THIS REASONING AND IS JUST EAST OF THE PREVIOUS FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0900Z 16.5N 52.7W 35 KT 12HR VT 15/1800Z 17.2N 54.0W 30 KT 24HR VT 16/0600Z 18.3N 55.6W 30 KT 36HR VT 16/1800Z 19.1N 56.9W 30 KT 48HR VT 17/0600Z 19.9N 58.2W 30 KT 72HR VT 18/0600Z 21.5N 59.5W 30 KT 96HR VT 19/0600Z 23.5N 60.5W 30 KT 120HR VT 20/0600Z 25.5N 61.5W 30 KT $$ FORECASTER MAINELLI