ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM ESTELLE DISCUSSION NUMBER 21 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062016 800 AM PDT WED JUL 20 2016 Estelle has generally changed little since the previous advisory. The convective pattern still consists of a well organized curved band that covers much of the eastern half of the circulation and fragmented bands to the west of the center. The initial wind speed is held at 60 kt for this advisory, which is an average of the Dvorak CI-numbers from TAFB and SAB. Estelle is crossing the 26 deg C isotherm and will be moving over progressively cooler water during the next few days. In addition, the storm will also be moving into an atmosphere of drier air and increasing westerly shear. Given these expected environmental conditions, steady weakening is forecast during the period, and Estelle will likely become a post-tropical cyclone in about 2 days when it is over SSTs around 22 deg C. The storm is moving westward at about 11 kt on the southwest side of a large subtropical ridge centered over the southern United States. Estelle is forecast to reach the western periphery of the ridge in a couple of days, which should induce a turn to the northwest. A northwestward motion is expected to continue until the system dissipates in 4 to 5 days. The models are in good agreement on this overall scenario, and the new NHC track forecast is largely an update of the previous one. This track prediction is in best agreement with a consensus of the GFS and ECMWF models. FORECAST POSITIONS AND MAX WINDS INIT 20/1500Z 19.2N 123.3W 60 KT 70 MPH 12H 21/0000Z 19.5N 125.3W 55 KT 65 MPH 24H 21/1200Z 20.2N 128.0W 50 KT 60 MPH 36H 22/0000Z 21.0N 130.8W 40 KT 45 MPH 48H 22/1200Z 22.1N 133.3W 35 KT 40 MPH...POST-TROPICAL 72H 23/1200Z 25.6N 137.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 24/1200Z 29.4N 141.1W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 25/1200Z...DISSIPATED $$ Forecaster Cangialosi NNNN