Issued at 500 PM AST Sat Aug 24 2019 000WTNT45 KNHC 242052TCDAT5Tropical Storm Dorian Discussion Number 2NWS National Hurricane Center Miami FL AL052019500 PM AST Sat Aug 24 2019Visible and passive microwave satellite imagery indicate that theinner-core of the small cyclone has noticeably improved since theprevious advisory. A 1705Z AMSR-2 overpass showed the developmentof tightly curved bands and a 10 mile wide eye-like feature. Inaddition, a 1935Z SSMI/S microwave pass revealed a tightly curvedband in 91 GHz data that wrapped almost 75 percent around thecenter. Based on the much improved inner-core structure and 33-ktwind vectors in an earlier ASCAT-B pass, the depression has beenupgraded to Tropical Storm Dorian on this advisory. Upper-leveloutflow has been improving to the northwest, but remains slightlyrestricted to the southeast due to some modest southeasterlyvertical wind shear.The initial motion is 280/11 kt. The latest NHC model guidanceremains in excellent agreement that Dorian will generally movewest-northwestward for the next 5 days around the southern peripheryof the sprawling Bermuda-Azores high pressure ridge that is locatedto the north of the Lesser and Greater Antilles. This motion isexpected to bring Dorian through the central or northern LesserAntilles on Tuesday, possibly as a hurricane, and then into thenortheastern Caribbean Sea on Wednesday and Thursday. The officialforecast track was shifted slightly north of the previous advisorytrack, and is close to the consensus model TVCN, which remains northof the NOAA HCCA corrected-consensus model.The moderate to strong vertical wind shear that has been hinderingdevelopment of this system for the past several days is forecast todiminish significantly during the next 12 h, and remain near 5 ktthrough Tuesday. The low shear conditions, along with warm SSTs andthe significantly improved small, inner-core structure, should allowfor at least slow but steady strengthening despite the abundance ofdry mid-level air nearby. However, the low vertical wind shear andtight inner-core wind field are also harbingers of possible rapidintensification. For now, the new intensity forecast remainsconservative and similar to the previous advisory, and is above allof the available intensity guidance, including the HWRF model.Key Messages:1. Dorian is forecast to strengthen and could be near hurricanestrength when it approaches the Lesser Antilles on Tuesday.2. It is too soon to determine the specific timing or magnitude ofimpacts in the Lesser Antilles, but tropical storm or hurricanewatches may be needed for a portion of the area on Sunday.FORECAST POSITIONS AND MAX WINDSINIT 24/2100Z 10.7N 49.1W 35 KT 40 MPH 12H 25/0600Z 11.0N 50.7W 40 KT 45 MPH 24H 25/1800Z 11.4N 52.8W 45 KT 50 MPH 36H 26/0600Z 11.9N 54.9W 50 KT 60 MPH 48H 26/1800Z 12.7N 57.0W 55 KT 65 MPH 72H 27/1800Z 14.6N 61.1W 65 KT 75 MPH 96H 28/1800Z 16.5N 65.3W 75 KT 85 MPH120H 29/1800Z 18.4N 69.0W 70 KT 80 MPH...INLAND$$Forecaster Stewart

More...