000 WTNT44 KNHC 071453 TCDAT4 Tropical Depression Fourteen Discussion Number 4 NWS National Hurricane Center Miami FL AL142018 1000 AM CDT Sun Oct 07 2018 Satellite and radar data indicate that the depression continues to become better organized, but surface data suggests the circulation may be somewhat elongated. There is still evidence of westerly shear as the center is located near the western edge of the main convective mass, but there has been an increase in banding over the eastern semicircle since yesterday afternoon. The depression appears to be close to tropical storm strength and Dvorak estimates from TAFB and SAB are between 30-35 kt. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the system early this afternoon and should provide a better assessment of the intensity of the cyclone. For now, the intensity is held at a possibly conservative 30 kt. The moderate westerly shear that is affecting the depression is forecast to gradually decrease over the next day or two as an upper-level trough over the Gulf of Mexico moves westward and weakens. This, in combination with warm waters, should allow for gradual strengthening as the system moves northward over the Gulf of Mexico. Nearly all of the intensity models bring the cyclone to hurricane strength over the Gulf of Mexico in 2 to 3 days, and the NHC forecast follows suit. The new NHC intensity forecast is slightly higher than the previous advisory and again lies near the ICON intensity consensus. This is a little below the more aggressive HWRF and HCCA models. The depression is moving northward at about 5 kt. The system is forecast to move generally northward during the next 2 to 3 days, with some increase in forward speed as it moves between a deep-layer ridge over the western Atlantic and a trough over the west-central United Sates. A northeastward turn is expected after 72 hours as the aforementioned trough progresses eastward across the central United States. The dynamical models generally agree on the overall scenario, but there are still large difference in forward speed. In fact, the ECMWF ensemble has members that are still over the Gulf of Mexico in 5 days, and others that reach southern New England in that time period. The NHC forecast is near the left side of the guidance envelope through 48 hours out of respect for the GFS and ECMWF that are both on that side of the track spread. After that time, the NHC track forecast is close to the various consensus aids to account for both the along and cross track spread of the guidance. Key Messages for Tropical Depression Fourteen: 1. The depression is forecast to produce heavy rainfall and flash flooding over portions of western Cuba and the northeastern Yucatan Peninsula of Mexico during the next couple of days. 2. The depression is forecast to become a tropical storm later today, and tropical storm conditions are expected by tonight over portions of western Cuba and the northeastern Yucatan Peninsula, where tropical storm warnings are in effect. 3. There is an increasing risk of dangerous storm surge, rainfall, and wind impacts over portions of the northern Gulf Coast by mid-week, although it is too soon to specify the exact location and magnitude of these impacts. Residents in these areas should monitor the progress of this system. FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 19.2N 86.9W 30 KT 35 MPH 12H 08/0000Z 20.0N 86.5W 40 KT 45 MPH 24H 08/1200Z 21.5N 86.5W 45 KT 50 MPH 36H 09/0000Z 23.2N 86.8W 55 KT 65 MPH 48H 09/1200Z 24.9N 87.2W 60 KT 70 MPH 72H 10/1200Z 28.7N 86.5W 70 KT 80 MPH 96H 11/1200Z 33.0N 82.5W 45 KT 50 MPH...INLAND 120H 12/1200Z 37.8N 73.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown