000 WTPZ41 KNHC 180248 TCDEP1 TROPICAL STORM SERGIO DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 700 PM PST FRI NOV 17 2006 AFTER BECOMING ALMOST COMPLETELY EXPOSED EARLIER TODAY...A NEW BURST OF DEEP CONVECTION HAS RECENTLY OCCURRED NORTHEAST OF THE LOW-LEVEL CIRCULATION. IN LIGHT OF THIS RECENT TREND...SERGIO IS MAINTAINED AS A 40-KT TROPICAL STORM. WHILE THE CYCLONE COULD CONTINUE TO PRODUCE INTERMITTENT BURSTS OF CONVECTION OVER THE NEXT DAY OR SO...INCREASING VERTICAL SHEAR AND DRY/STABLE AIR ARE EXPECTED TO ULTIMATELY CAUSE WEAKENING. SERGIO HAS MADE AN ABRUPT TURN TOWARD THE NORTHWEST OVER THE LAST SEVERAL HOURS WITH AN INITIAL MOTION ESTIMATE OF 315/6. A GENERAL WEST-NORTHWEST TO NORTHWESTWARD MOTION IS EXPECTED UNTIL DISSIPATION. THE OFFICIAL FORECAST TRACK HAS BEEN SHIFTED SOUTH OF THE PREVIOUS ONE AND LIES TOWARD THE LEFT SIDE OF THE GUIDANCE ENVELOPE IN ANTICIPATION OF THE CYCLONE BECOMING INCREASINGLY SHALLOW. THIS TRACK IS IN BETWEEN THE SHALLOW AND MEDIUM BAM MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 18/0300Z 14.5N 103.1W 40 KT 12HR VT 18/1200Z 15.1N 103.7W 35 KT 24HR VT 19/0000Z 15.9N 104.8W 30 KT 36HR VT 19/1200Z 16.5N 106.0W 25 KT...REMNANT LOW 48HR VT 20/0000Z 17.0N 107.4W 25 KT...REMNANT LOW 72HR VT 21/0000Z...DISSIPATED $$ FORECASTER RHOME 000 WTPZ41 KNHC 180248 TCDEP1 TROPICAL STORM SERGIO DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 700 PM PST FRI NOV 17 2006 AFTER BECOMING ALMOST COMPLETELY EXPOSED EARLIER TODAY...A NEW BURST OF DEEP CONVECTION HAS RECENTLY OCCURRED NORTHEAST OF THE LOW-LEVEL CIRCULATION. IN LIGHT OF THIS RECENT TREND...SERGIO IS MAINTAINED AS A 40-KT TROPICAL STORM. WHILE THE CYCLONE COULD CONTINUE TO PRODUCE INTERMITTENT BURSTS OF CONVECTION OVER THE NEXT DAY OR SO...INCREASING VERTICAL SHEAR AND DRY/STABLE AIR ARE EXPECTED TO ULTIMATELY CAUSE WEAKENING. SERGIO HAS MADE AN ABRUPT TURN TOWARD THE NORTHWEST OVER THE LAST SEVERAL HOURS WITH AN INITIAL MOTION ESTIMATE OF 315/6. A GENERAL WEST-NORTHWEST TO NORTHWESTWARD MOTION IS EXPECTED UNTIL DISSIPATION. THE OFFICIAL FORECAST TRACK HAS BEEN SHIFTED SOUTH OF THE PREVIOUS ONE AND LIES TOWARD THE LEFT SIDE OF THE GUIDANCE ENVELOPE IN ANTICIPATION OF THE CYCLONE BECOMING INCREASINGLY SHALLOW. THIS TRACK IS IN BETWEEN THE SHALLOW AND MEDIUM BAM MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 18/0300Z 14.5N 103.1W 40 KT 12HR VT 18/1200Z 15.1N 103.7W 35 KT 24HR VT 19/0000Z 15.9N 104.8W 30 KT 36HR VT 19/1200Z 16.5N 106.0W 25 KT...REMNANT LOW 48HR VT 20/0000Z 17.0N 107.4W 25 KT...REMNANT LOW 72HR VT 21/0000Z...DISSIPATED $$ FORECASTER RHOME