ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM TROPICAL STORM GIL DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013 800 AM PDT SAT AUG 03 2013 ALTHOUGH SEVERAL BURSTS OF DEEP CONVECTION HAVE OCCURED NEAR THE CENTER OF GIL DURING THE PAST FEW HOURS...THE STRUCTURE IS STILL BEING DISTRUPTED BY DEEP-LAYER SHEAR. SATELLITE INTENSITY ESTIMATES FROM TAFB...SAB...AND UW-CIMSS AVERAGE TO ABOUT 50 KT...AND GIVEN THAT THE CLOUD STRUCTURE HAS NOT CHANGED SUBSTANTIALLY DURING THE PAST 6 HOURS...THE INTENSITY HAS BEEN HELD AT AT THAT VALUE. ALL OF THE INTENSITY MODELS INDICATE THAT GIL WILL WEAKEN DURING THE NEXT COUPLE OF DAYS WHILE IT INTERACTS WITH AN UPPER-LEVEL TROUGH TO THE NORTHWEST. AFTER THAT TIME...THE DYNAMICAL MODELS SUGGEST THAT GIL WILL QUICKLY WEAKEN TO A REMNANT LOW...WHILE THE STATISTICAL MODELS SUGGEST THAT SOME RESTRENGTHENING COULD OCCUR...PRIMARILY DUE TO DECREASING SHEAR. THE OFFICIAL FORECAST LIES BETWEEN THESE TWO POSSIBILITIES AND IS NEAR THE MULTI-MODEL CONSENSUS. GIL HAS BEEN MOVING STEADILY WESTWARD ALONG THE SOUTHWEST PERIPHERY OF A MID-LEVEL RIDGE AND THE INITIAL MOTION IS 275/10. THE GLOBAL MODELS FORECAST THAT THIS RIDGE WILL BUILD SLIGHTLY TO THE SOUTHWEST...WHICH SHOULD CAUSE THE TROPICAL CYCLOENN TO TURN TOWARD THE WEST-SOUTHWEST. A TURN BACK TOWARD THE WEST IS EXPECTED AS GIL WEAKENS AND IS STEERED PRIMARILY BY THE LOW-LEVEL EASTERLY FLOW. THE TRACK GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT AND THE GUIDANCE ENVELOPE IS CENTERED AROUND THE PAST COUPLE NHC FORECASTS. THE NEW FORECAST IS THEREFORE MERELY AN UPDATE OF THE PREVIOUS TRACK FORECAST. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 15.0N 132.6W 50 KT 60 MPH 12H 04/0000Z 15.0N 133.8W 45 KT 50 MPH 24H 04/1200Z 14.8N 135.3W 45 KT 50 MPH 36H 05/0000Z 14.4N 136.7W 40 KT 45 MPH 48H 05/1200Z 14.0N 138.2W 40 KT 45 MPH 72H 06/1200Z 13.2N 140.8W 35 KT 40 MPH 96H 07/1200Z 13.0N 143.5W 35 KT 40 MPH 120H 08/1200Z 13.0N 147.0W 30 KT 35 MPH $$ FORECASTER FRANKLIN/ZELINSKY NNNN