The earliest H-named storm ever in the Atlantic basin is gaining strength and forecast to make landfall as a hurricane in Texas on Saturday afternoon or evening.
Tropical Storm Hanna is forecast to be a Category 1 hurricane with sustained winds of 75 mph when it makes landfall along the south-central coast of Texas, according to the National Hurricane Center in Miami, Florida.
“Steady strengthening is forecast for the next 24 hours, and Hanna is expected to become a hurricane before the cyclone makes landfall,” according to an advisory from the hurricane center.
The storm currently has sustained winds of 65 mph that extend 60 miles out from the center as it moves across the Gulf of Mexico toward Texas.
“Storms like Hanna in the Gulf of Mexico are notoriously the hardest to forecast,” CNN meteorologist Chad Myers says. “The water is so warm under the storm that rapid intensification can happen at any time, especially overnight when atmospheric shear goes down naturally. “
Shear is the changing of wind speed and direction with height and can inhibit hurricanes from forming.
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If Hanna strengthens into a hurricane, it will be the first hurricane of the season in the Atlantic. As of 10 p.m. Friday, the storm was 165 miles (270 km) east-southeast of Corpus Christi, Texas.
An eye is beginning to form based off radar imagery, the hurricane center said, which means the storm is better organized and developing a stronger core structure.
Hurricane warnings issued in Texas
The National Weather Service issued a hurricane warning for the area along the southern Texas coast from Baffin Bay to Mesquite Bay, which includes Corpus Christi. Additional areas of Texas were added to the warning late Friday to extend from Port Mansfield to Mesquite Bay.
Tropical storm conditions are likely to begin within the warning area on Friday night with hurricane conditions expected on Saturday afternoon.
A tropical storm warning is in effect from the mouth of the Rio Grande near Brownsville, Texas, to Baffin Bay and from Mesquite Bay to San Luis Pass, just south of Galveston, Texas. Other areas of the warning include Barra el Mezquital, Mexico to Port Mansfield, Texas, and from Mesquite Bay to High Island, Texas.
A storm surge warning was issued for the area from Baffin Bay to Sargent, Texas, including Corpus Christi Bay, Copano Bay, Aransas Bay, San Antonio Bay and Matagorda Bay. This means there is a danger in this area of life-threatening inundation from rising water moving inland from the coastline, according to the hurricane center.
Hanna is expected to produce 5 to 10 inches of rain with isolated maximum totals of 15 inches through Sunday night in south Texas and into the Mexican states of Coahuila, Nuevo Leon and northern Tamaulipas.
“This rain may result in life-threatening flash flooding, rapid rises on small streams, and isolated minor to moderate river flooding in south Texas,” the hurricane center said.
Along the upper Texas and Louisiana coasts, 3 to 5 inches is of rain is forecast.
Hanna is expected to generate increase swells that will affect the Texas and Louisiana coasts during the next few days and the swells are likely to cause life-threatening surf and rip current conditions, forecasters said.
Though still very early, experts predict this year will have an active hurricane season.
The previous record for the earliest H-named storm was set by Tropical Storm Harvey on August 3, 2005.