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| #1019669 (Received by flhurricane at: 4:36 PM 02.Oct.2020) TCDAT5 Tropical Depression Twenty-Five Discussion Number 2 NWS National Hurricane Center Miami FL AL252020 400 PM CDT Fri Oct 02 2020 Convective banding features have become a little better defined over the southern portion of the circulation, but otherwise the system has not changed much in organization since earlier today. The current intensity estimate remains at 30 kt in agreement with a Dvorak estimate from TAFB, and scatterometer observations from a few hours ago. The SHIPS model output now shows some south-southwesterly shear affecting the system during the next few days. Otherwise, the environment should favor at least gradual strengthening, and the cyclone is likely to become a tropical storm prior to moving near the Yucatan Peninsula. The official intensity forecast is within the range of most of the model guidance. The initial motion estimate is the same as in the morning advisory, 315/8 kt. The depression should move along the southwestern periphery of a mid-tropospheric high pressure area for the next couple of days, causing the cyclone to move on a northwestward to north-northwestward heading. Later in the forecast period, the global models build a weak ridge across the northern half of the Gulf of Mexico. This should induce the cyclone to turn westward or even a little south of west in 3-5 days. The latest NHC forecast lies between the simple and corrected dynamical model consensus predictions, TVCA and HCCA, and is quite similar to the previous official forecast. At this time, the biggest threat from this slow-moving system is rain and flooding, particularly near and over mountainous terrain. KEY MESSAGES: 1. The system is expected to produce heavy rainfall that could result in life-threatening flash flooding over portions of the Yucatan Peninsula, far western Cuba and well away from the center in the Mexican states of Campeche, Tabasco, and northern Chiapas. 2. The depression is forecast to become a tropical storm and bring tropical storm conditions to portions of the Yucatan Peninsula on Saturday, where a Tropical Storm Warning is in effect. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 18.8N 85.3W 30 KT 35 MPH 12H 03/0600Z 19.5N 86.1W 35 KT 40 MPH 24H 03/1800Z 20.5N 87.0W 40 KT 45 MPH 36H 04/0600Z 21.6N 87.5W 40 KT 45 MPH 48H 04/1800Z 22.3N 87.7W 40 KT 45 MPH 60H 05/0600Z 22.5N 88.0W 45 KT 50 MPH 72H 05/1800Z 22.5N 88.8W 50 KT 60 MPH 96H 06/1800Z 22.5N 91.0W 50 KT 60 MPH 120H 07/1800Z 22.0N 92.5W 50 KT 60 MPH $$ Forecaster Pasch |