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#1009495 (Received by flhurricane at: 10:54 PM 24.Jul.2020) TCDAT3 Tropical Storm Hanna Discussion Number 9 NWS National Hurricane Center Miami FL AL082020 1000 PM CDT Fri Jul 24 2020 Hanna continues to strengthen over the northwestern Gulf of Mexico. Satellite and Doppler radar images indicate that the inner core continues to become better organized and the outer bands are now more symmetrical around the center. The NOAA Hurricane Hunters are currently investigating Hanna and have found maximum 850 mb flight-level winds of 72 kt and maximum SFMR winds of 51 kt. Based on this data, the initial intensity is increased to 55 kt for this advisory. The aircraft has also reported a minimum pressure of 992 mb, which is a 8 mb drop from the flight earlier today. The NOAA aircraft data indicate that the center has moved a little south of west during the past few hours, and the storm is now a little south of the previous forecast track. A strengthening subtropical ridge over the central U.S. should cause the storm to continue to move generally westward, taking the center across the southern Texas coast tomorrow afternoon or early evening. After landfall, the storm is expected to turn to the west-southwest or southwest across extreme southern Texas and northern Mexico, and that motion should continue until the system dissipates. Hanna still has another 18 hours or so to strengthen as it remains in light wind shear conditions and over the warm Gulf of Mexico waters. Since the structure of the system continues to improve, it seems likely that Hanna will reach hurricane intensity before it makes landfall. The peak intensity could be higher than what is shown in the intensity forecast below since landfall is expected to occur between the 12 and 24 h forecast times. After landfall, rapid weakening is anticipated, and Hanna is expected to dissipate on Monday over the rugged terrain of northern Mexico. The NHC intensity forecast lies at the high end of the model guidance for the next 24 h. 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 Port Mansfield 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 25/0300Z 27.1N 94.8W 55 KT 65 MPH 12H 25/1200Z 27.1N 96.1W 65 KT 75 MPH 24H 26/0000Z 27.0N 97.7W 60 KT 70 MPH...INLAND 36H 26/1200Z 26.6N 99.3W 35 KT 40 MPH...INLAND 48H 27/0000Z 25.9N 101.0W 25 KT 30 MPH...INLAND 60H 27/1200Z 25.2N 102.4W 20 KT 25 MPH...POST-TROP/INLAND 72H 28/0000Z...DISSIPATED $$ Forecaster Cangialosi |