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| #858182 (Received by flhurricane at: 10:49 AM 28.May.2016) TCDAT2 TROPICAL DEPRESSION TWO DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL022016 1100 AM EDT SAT MAY 28 2016 Satellite and NOAA WSR-88D radar data indicate that deep convection has increased in the northern semicircle of the depression's circulation since the previous advisory. However, the depression remains a sheared tropical cyclone due to southeasterly upper-level winds of 20-25 kt. An Air Force Reserve reconnaissance aircraft investigated the cyclone this morning and obtained reliable SFMR surface winds of at least 30 kt. Satellite intensity estimates were also T2.0/30 kt from both TAFB and SAB, so the intensity is being maintained at 30 kt for this advisory. Microwave satellite and recon fix positions indicate that the cyclone has made a jog toward the west-northwest during the past six hours. However, smoothing through these short-term wobbles yields a 12-hour motion of 310/11 kt. The ECMWF and GFS models actually did quite well in predicting this recent short-term wobble, and both models turn the depression more toward the right, accompanied by a steady decrease in forward speed over the next 24 hours as the cyclone nears the South Carolina coast. As a result, the new NHC forecast track lies slightly to the left of the previous advisory track through 12 hours, primarily to account for the more westward initial position, and then is near the previous track and a blend of the GFS-ECMWF model consensus track at 24 hours and beyond. The depression is beginning to move over the eastern wall of the Gulf Stream where sea-surface temperatures are 27-28 deg C. Outer convective bands have also developed over the slightly cooler shelf waters between the South Carolina coast and the Gulf Stream, which implies that there might not be as much of a weakening effect by those cooler waters as previously anticipated. However, southerly vertical wind shear is forecast by the SHIPS model to increase to more than 20 kt before the cyclone reaches the coast, and that is expected to inhibit any significant strengthening. It is possible that the cyclone could peak at around 40 kt while it is over the Gulf Stream this afternoon and evening, followed by slight weakening just before it reaches the coast. The official intensity forecast is similar to the previous advisory and closely follows the Decay-SHIPS intensity model. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 30.3N 78.5W 30 KT 35 MPH 12H 29/0000Z 31.3N 79.5W 35 KT 40 MPH 24H 29/1200Z 32.4N 80.3W 35 KT 40 MPH 36H 30/0000Z 32.7N 80.3W 30 KT 35 MPH...INLAND 48H 30/1200Z 33.0N 79.7W 30 KT 35 MPH...INLAND 72H 31/1200Z 33.6N 78.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 01/1200Z 34.4N 76.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 02/1200Z 34.9N 75.8W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart |
