ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM TROPICAL STORM KEVIN DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP142015 200 AM PDT THU SEP 03 2015 Recent ASCAT data indicate that the cyclone is producing a sizable area of 35-kt winds, especially beneath a burst of deep convection which has persisted during the past few hours. The scatterometer data also indicated that the low-level center is now embedded beneath the southeastern edge of the convective canopy, and Dvorak estimates are a consensus T2.5/35 kt from TAFB and SAB. Based on these data, the cyclone is being upgraded to Tropical Storm Kevin. Although some southerly shear is expected to continue affecting Kevin during the next several days, warm sea surface temperatures and a moist environment could support just a little more strengthening during the next 24 hours. The NHC intensity forecast has been adjusted slightly upward during that period and shows a peak intensity close to the ICON intensity consensus and the Florida State Superensemble. After 36 hours, the shear is likely to allow drier air to get into the circulation, leading to weakening. Kevin is forecast to degenerate to a remnant low by day 3 and dissipate around day 5. With the help of the ASCAT data, the low-level center was adjusted a tad west of where it was previously estimated, and the initial motion estimate is 350/5 kt. Kevin should continue northward between a mid-level anticyclone over Mexico and a deep-layer trough off the west coast of North America for the next 36 hours. Once the cyclone weakens and is no longer producing significant deep convection, the center is expected to turn westward in the low-level flow. The global models appear to be in better agreement on when this turn will occur, and the bulk of the guidance now shows a sharper westward turn after 48 hours. The new NHC track forecast is therefore a bit west of the previous forecast and is close to the TVCE dynamical consensus. FORECAST POSITIONS AND MAX WINDS INIT 03/0900Z 17.5N 115.3W 35 KT 40 MPH 12H 03/1800Z 18.4N 115.5W 40 KT 45 MPH 24H 04/0600Z 19.6N 115.5W 40 KT 45 MPH 36H 04/1800Z 20.6N 115.4W 35 KT 40 MPH 48H 05/0600Z 21.3N 115.6W 30 KT 35 MPH 72H 06/0600Z 22.1N 117.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 07/0600Z 22.1N 119.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 08/0600Z...DISSIPATED $$ Forecaster Berg NNNN