Tropical Storm SERGIO
ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM SERGIO DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 700 AM PST FRI NOV 17 2006 THE CLOUD PATTERN HAS BEEN DETERIORATING AND NOW CONSISTS OF A SHAPELESS MASS OF CLOUDS. ALTHOUGH THERE HAS BEEN NO MICROWAVE DATA OVER THE SYSTEM DURING THE PAST SEVERAL HOURS...CONVENTIONAL IMAGERY SUGGEST THAT THE LOW-LEVEL CENTER IS LOCATED WEST OF THE REMAINING CONVECTION. T-NUMBERS STILL SUPPORT AN INITIAL INTENSITY OF 55 KNOTS. HOWEVER...THE SOUTHWESTERLY SHEAR IS ALREADY OVER THE SYSTEM AND IS NOT EXPECTED TO DECREASE. THEREFORE A GRADUAL WEAKENING IS FORECAST. THE INITIAL MOTION CONTINUES TO BE UNCERTAIN. SERGIO APPEARS TO BE DRIFTING TOWARD THE NORTH-NORTHEAST AT 3 KNOTS BUT WITH A DEVELOPING RIDGE TO THE NORTH AND NORTHEAST OF THE CYCLONE...A TURN TO THE NORTH AND NORTHWEST SHOULD BEGIN SOON. FURTHERMORE...SERGIO IS EXPECTED TO WEAKEN AND EVENTUALLY BECOME STEERED NORTHWESTWARD BY THE LOW-LEVEL FLOW. THIS IS CONSISTENT WITH THE TRACK GUIDANCE WHICH UNANIMOUSLY SHOW THE TURN TO THE NORTHWEST DURING THE NEXT DAY OR TWO. RAINBANDS APPROACHING THE SOUTHWEST OF MEXICO HAVE BEGUN TO WEAKEN. THEREFORE... THE POTENTIAL RAINFALL THREAT HAS DIMINISHED. FORECAST POSITIONS AND MAX WINDS INITIAL 17/1500Z 14.2N 102.5W 55 KT 12HR VT 18/0000Z 14.7N 102.5W 50 KT 24HR VT 18/1200Z 15.5N 103.0W 45 KT 36HR VT 19/0000Z 16.5N 104.0W 40 KT 48HR VT 19/1200Z 17.0N 105.0W 35 KT 72HR VT 20/1200Z 18.0N 107.0W 30 KT 96HR VT 21/1200Z 19.0N 109.0W 25 KT 120HR VT 22/1200Z 20.0N 112.0W 20 KT...REMNANT LOW $$ FORECASTER AVILA NNNN