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#1009374 (Received by flhurricane at: 4:45 AM 24.Jul.2020) TCDAT3 Tropical Storm Hanna Discussion Number 6 NWS National Hurricane Center Miami FL AL082020 400 AM CDT Fri Jul 24 2020 Satellite imagery shows well-defined convective banding features over the eastern and southern portions of the circulation with some cooling of the cloud tops. This suggests that the associated thunderstorm activity is becoming more vigorous. However, surface observations over the Gulf and a scatterometer pass from a few hours ago indicate that the system has not strengthened further at this time. The current intensity estimate is held at 35 kt in agreement with a Dvorak classification from TAFB. A NOAA Hurricane Hunter aircraft is scheduled to investigate the storm later this morning and they should provide a good estimate of Hanna`s intensity. The storm has an impressive upper-level anticyclonic outflow structure and should remain in a low shear environment until it reaches the coast. Therefore strengthening is likely prior to landfall and the NHC intensity forecast is near the model high end of the intensity model suite. The storm has moved a little faster toward the west-northwest over the past several hours, and the initial motion estimate is 290/8 kt. There is very little change to the official track forecast or reasoning from the previous cycle. A gradual turn toward the west is likely in 12 hours or so as a mid-level ridge to the north of Hanna builds a bit. The forecast track takes the center inland over Texas within the tropical storm warning area on Saturday. This is in good agreement with the dynamical model consensus and the latest ECMWF model solution. Key Messages 1. Hanna is forecast to strengthen and it is expected to bring tropical-storm-force winds to portions of the Texas coast, where a tropical storm warning is in effect. 2. Hanna is expected to produce heavy rains across portions of southern Texas. These rains could result in flash flooding and isolated minor to moderate river flooding. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 26.7N 92.4W 35 KT 40 MPH 12H 24/1800Z 27.1N 93.7W 40 KT 45 MPH 24H 25/0600Z 27.3N 95.5W 50 KT 60 MPH 36H 25/1800Z 27.3N 97.1W 55 KT 65 MPH 48H 26/0600Z 27.2N 98.6W 40 KT 45 MPH...INLAND 60H 26/1800Z 26.5N 100.0W 30 KT 35 MPH...INLAND 72H 27/0600Z 26.0N 101.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 28/0600Z...DISSIPATED $$ Forecaster Pasch |