Official Discussion issued by the National Hurricane Center

Twenty-Five (AL252020) DATA RELEASED: 10/2/2020 4:00:00 PM UTC

Copy of official data

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