Official Discussion issued by the National Hurricane Center

Hanna (AL082020) DATA RELEASED: 7/24/2020 4:00:00 PM UTC

Copy of official data

Tropical Storm Hanna Discussion Number   8
NWS National Hurricane Center Miami FL       AL082020
400 PM CDT Fri Jul 24 2020

Satellite imagery, along with Doppler radar data from Houston and 
Corpus Christi, indicate that Hanna has been getting better 
organized over the past several hours. Curved banding features have 
improved and a banding eye has developed in the radar data. The NOAA 
reconnaissance aircraft reported SFMR winds of 43-45 kt on its last 
outbound leg and a ship D5DE5 just east of the center reported an 
elevated wind speed of 51 kt at 1400Z. Based on these data, along 
with an estimated pressure of 999 mb from surrounding oil rigs, the 
initial intensity has been conservatively increased to 45 kt.

Reconnaissance and radar fix data indicate that Hanna has turned 
westward, and the motion is now 275/09 kt. Hanna is forecast to move 
generally westward along the southern periphery of a deep-layer 
ridge for the next 24 hours, with landfall expected along the 
south-central coast of Texas within the hurricane warning area 
Saturday afternoon or early evening. The new NHC forecast track is 
just an extension of the previous advisory track, and lies close to 
an average of the consensus models TVCN, NOAA-HCCA, and FSSE.

Given the improved internal structure noted in radar imagery, along 
with SSTs of at least 30 deg C and an impressive outflow pattern, 
increased frictional convergence as the cyclone moves closer to the 
coast and the approaching nocturnal convective maximum should 
support additional strengthening, and Hanna is now forecast 
to become a hurricane prior to making landfall. The NHC forecast of 
65 kt in 24 hours is between the latest HWRF model run, which 
brings Hanna to 70 kt just prior to landfall, and the intensity 
consensus models HCCA and IVCN, which are just below hurricane 
strength.

Due to Hanna forecast to reach hurricane strength, Hurricane and 
Storm Surge Warnings have been issued for portions of the Texas 
coast.

Key Messages

1. There is a danger of life-threatening storm surge along the Texas 
coast from Baffin Bay to Sargent, where a Storm Surge Warning is in 
effect. Residents in these locations should follow advice given by 
local emergency officials. 

2. Hurricane conditions are expected along the Texas coast from 
Baffin Bay to Mesquite Bay, where a Hurricane Warning is in effect. 
Tropical storm conditions are expected to first reach the coast 
within the warning area Saturday morning. 

3. Hanna is expected to produce heavy rains across portions of 
southern Texas and northeastern Mexico.  These rains could result in 
life-threatening flash flooding and isolated minor to moderate river 
flooding.

FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 27.3N  94.3W   45 KT  50 MPH
12H  25/0600Z 27.4N  95.6W   55 KT  65 MPH
24H  25/1800Z 27.3N  97.2W   65 KT  75 MPH
36H  26/0600Z 27.0N  98.6W   40 KT  45 MPH...INLAND
48H  26/1800Z 26.6N 100.3W   25 KT  30 MPH...INLAND
60H  27/0600Z 25.6N 102.0W   20 KT  25 MPH...INLAND
72H  27/1800Z...DISSIPATED

$$
Forecaster Stewart