Tropical Depression Hanna Advisory 16

1. Tropical storm conditions are expected to persist for several more hours near the center of Hanna, and for a few more hours in the warning area along the coast of Texas and northeastern Mexico.xx

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

3. Storm surge along the Texas coast should diminish today.xx

1. Tropical storm conditions are expected to persist for several more hours near the center of Hanna, and for a few more hours in the warning area along the coast of Texas and northeastern Mexico.xx

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

3. Storm surge along the Texas coast should diminish today.xx

There are no coastal watches or warnings in effect.

Interests in northeastern Mexico should monitor the progress of Hanna. For storm information specific to your area, please monitor products issued by your national meteorological service.

There are no coastal watches or warnings in effect.

Interests in northeastern Mexico should monitor the progress of Hanna. For storm information specific to your area, please monitor products issued by your national meteorological service.

Key messages for Hanna can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3, WMO header WTNT43 KNHC and on the web at www.hurricanes.gov/text/MIATCDAT3.shtml.

RAINFALL: Hanna is expected to produce the following rain accumulations and flood threats through Monday: South Texas...Additional 2 to 5 inches. Storm total amounts 6 to 12 inches, isolated 16 inches. Northern Mexican states of Coahuila, Nuevo Leon, Tamaulipas...6 to 12 inches, isolated 16 inches. Northern Mexican states of northern Zacatecas, northern San Luis Potosi, and eastern Durango...1 to 4 inches. This rain will produce lifethreatening flash flooding, rapid rises on small streams, and isolated minor river flooding in South Texas. Flash flooding and mudslides are likely across Northern Mexican states.

SURF: Swells generated by Hanna will continue to affect much of the Texas and northeastern Mexico coasts through early Monday. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

TORNADOES: Isolated tornadoes are possible through this evening across parts of south Texas

Key messages for Hanna can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3, WMO header WTNT43 KNHC and on the web at www.hurricanes.gov/text/MIATCDAT3.shtml.

RAINFALL: Hanna is expected to produce the following rain accumulations and flood threats through Monday: South Texas...Additional 2 to 5 inches. Storm total amounts 6 to 12 inches, isolated 16 inches. Northern Mexican states of Coahuila, Nuevo Leon, Tamaulipas...6 to 12 inches, isolated 16 inches. Northern Mexican states of northern Zacatecas, northern San Luis Potosi, and eastern Durango...1 to 4 inches. This rain will produce lifethreatening flash flooding, rapid rises on small streams, and isolated minor river flooding in South Texas. Flash flooding and mudslides are likely across Northern Mexican states.

SURF: Swells generated by Hanna will continue to affect much of the Texas and northeastern Mexico coasts through early Monday. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

TORNADOES: Isolated tornadoes are possible through this evening across parts of south Texas

At 400 PM CDT (2100 UTC), the center of Tropical Depression Hanna was located near latitude 25.6 North, longitude 100.6 West. The depression is moving toward the westsouthwest near 9 mph (15 km/h), and this motion is expected to continue through Monday. On the forecast track, the center of Hanna should continue to move farther inland over northeastern Mexico. Maximum sustained winds have decreased to near 35 mph (55 km/h) with higher gusts. Additional weakening is expected as the center of Hanna moves farther inland. Hanna is expected to become a remnant low on Monday and dissipate by Monday night.

The estimated minimum central pressure is 1002 mb (29.59 inches).

At 400 PM CDT (2100 UTC), the center of Tropical Depression Hanna was located near latitude 25.6 North, longitude 100.6 West. The depression is moving toward the westsouthwest near 9 mph (15 km/h), and this motion is expected to continue through Monday. On the forecast track, the center of Hanna should continue to move farther inland over northeastern Mexico. Maximum sustained winds have decreased to near 35 mph (55 km/h) with higher gusts. Additional weakening is expected as the center of Hanna moves farther inland. Hanna is expected to become a remnant low on Monday and dissipate by Monday night.

The estimated minimum central pressure is 1002 mb (29.59 inches).

Hanna continues to weaken as the center crosses the Rio Grande River from Texas into northeastern Mexico. Satellite imagery shows some warming of the cloud tops near the center, and WSR-88D radar data shows that only about a third of the previous eyewall is still present to the southeast of the center. The storm is generating a vigorous outer convective band over the eastern semicircle. The initial intensity is reduced to 50 kt based mainly on Doppler radar winds of 50-65 kt at about 9000 ft to the northeast of the center, and it is possible that this is generous. The initial motion remains west-southwestward or 250/8 kt. The mid-level ridge over the central United States should continue to steer Hanna west-southwestward until dissipation, and the new NHC forecast track is little changed from the previous forecast. Hanna should rapidly weaken as it moves over northeastern Mexico, with the system expected to weaken to a depression in 12-18 h, if not sooner. The system is expected to dissipate completely over the rugged terrain of Mexico between 36-48 h. The radar signature of the storm has weakened to the point where there will be no more hourly position updates between advisories.

Key Messages

1. Tropical storm conditions are expected to persist for several more hours near the center of Hanna, and for a few more hours in the warning area along the coast of Texas and northeastern Mexico.

2. Hanna is expected to produce heavy rains across portions of southern Texas and northeastern Mexico. These rains will result in life-threatening flash flooding and isolated minor to moderate river flooding. 3. Storm surge along the Texas coast should diminish today.

Hanna continues to weaken as the center crosses the Rio Grande River from Texas into northeastern Mexico. Satellite imagery shows some warming of the cloud tops near the center, and WSR-88D radar data shows that only about a third of the previous eyewall is still present to the southeast of the center. The storm is generating a vigorous outer convective band over the eastern semicircle. The initial intensity is reduced to 50 kt based mainly on Doppler radar winds of 50-65 kt at about 9000 ft to the northeast of the center, and it is possible that this is generous. The initial motion remains west-southwestward or 250/8 kt. The mid-level ridge over the central United States should continue to steer Hanna west-southwestward until dissipation, and the new NHC forecast track is little changed from the previous forecast. Hanna should rapidly weaken as it moves over northeastern Mexico, with the system expected to weaken to a depression in 12-18 h, if not sooner. The system is expected to dissipate completely over the rugged terrain of Mexico between 36-48 h. The radar signature of the storm has weakened to the point where there will be no more hourly position updates between advisories.

Key Messages

1. Tropical storm conditions are expected to persist for several more hours near the center of Hanna, and for a few more hours in the warning area along the coast of Texas and northeastern Mexico.

2. Hanna is expected to produce heavy rains across portions of southern Texas and northeastern Mexico. These rains will result in life-threatening flash flooding and isolated minor to moderate river flooding. 3. Storm surge along the Texas coast should diminish today.

AL082020 Tropical Depression Hanna