000 WTNT44 KNHC 070235 TCDAT4 Potential Tropical Cyclone Fourteen Discussion Number 2 NWS National Hurricane Center Miami FL AL142018 1000 PM CDT Sat Oct 06 2018 The cloud pattern has improved in organization and surface pressures are gradually falling, but there is no evidence that the system is a tropical cyclone at this time. All indications are, however, that a tropical depression will likely form at any time soon. Strong wind shear is expected to affect the disturbance, and the SHIPS model only show a modest strengthening. This is in contrast to some global models and the HWRF, which are more aggressive in developing this system. Since the environment is marginally favorable, the NHC forecast only gradually strengthens the system at the rate of the intensity consensus IVCN. However, the forecast is highly uncertain given the solution of the global models. Since the system does not have a well-defined center, the initial motion is also uncertain. The best estimate is toward the north or 360 degrees at 6 kt. Over the next 2 or 3 days, the cyclone will be embedded within the deep southerly flow between a strong subtropical ridge over the western Atlantic and a sharp mid-latitude trough advancing eastward over the United States. This flow pattern will force the system to move northward at 5 to 10 kt across the eastern Gulf of Mexico for the next 2 to 3 days. By day 4, the system should have moved inland and be weakening. It should then race northeastward farther inland across the eastern U.S. The track guidance envelope is remarkably quite tight. This increases the confidence in the track forecast primarily after the cyclone forms. Key Messages for Potential Tropical Cyclone Fourteen: 1. This system is producing heavy rainfall and flash flooding over portions of Central America, and these rains will spread over western Cuba and the northeastern Yucatan Peninsula of Mexico during the next couple of days. 2. The system is forecast to become a tropical storm by late Sunday, and tropical storm conditions are expected over portions of western Cuba, where a Tropical Storm Warning is in effect. 3. The system could bring storm surge, rainfall, and wind impacts to 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 07/0300Z 18.8N 86.6W 25 KT 30 MPH...POTENTIAL TROP CYCLONE 12H 07/1200Z 19.5N 86.5W 30 KT 35 MPH...TROPICAL CYCLONE 24H 08/0000Z 21.0N 86.2W 35 KT 40 MPH 36H 08/1200Z 22.3N 86.1W 40 KT 45 MPH 48H 09/0000Z 23.8N 86.3W 45 KT 50 MPH 72H 10/0000Z 27.4N 87.2W 55 KT 65 MPH 96H 11/0000Z 32.0N 85.0W 30 KT 35 MPH...INLAND 120H 12/0000Z 38.5N 77.5W 30 KT 35 MPH...INLAND $$ Forecaster Avila