Updated at 1:05 p.m. ET
Hurricane Harvey is getting stronger and could make landfall in the middle of the Texas coast as a Category 3 hurricane Friday night, the National Hurricane Center says, warning of the potential for a deadly storm surge and flooding along the Gulf of Mexico.
The storm's winds were rated at 80 mph around midday on Thursday — but they could reach 115 mph in the next 36 hours, forecasters say, announcing that the middle Texas coast is currently under a hurricane warning.
Harvey "intensified quickly" Thursday morning and could bring a storm surge of 6 to 10 feet above ground level; rainfall of 12 to 20 inches could bring floods, with some areas getting as much as 30 inches of water from Friday into next week, the National Weather Service agency said in an advisory Thursday morning.
"On the forecast track, Harvey will approach the middle Texas coast on Friday and make landfall Friday night or early Saturday, and then stall near the middle Texas coast through the weekend," the hurricane center says.
A storm surge warning is in effect for hundreds of miles of the Texas coastline, from Port Mansfield near South Padre Island to San Luis Pass just south of Galveston.
Beaches and schools in the storm's path are closing. The Corpus Christi office of the National Weather Service is urging residents to finish their preparations for the storm now, before conditions deteriorate. To combat flooding, the city of Corpus Christi is currently providing residents up to 20 sandbags each.
Houston schools have canceled classes for Monday, Houston Public Media reports, with the threat of bad weather putting off what had been scheduled to be the first day of the school year for the Houston Independent School District.
The forecast for Harvey "has become quite concerning," the hurricane center says, after an Air Force Reserve Hurricane Hunter aircraft found the storm's center early Thursday. The storm was seen at the verge of becoming a hurricane, with central pressure that continues to fall and the storm predicted to strengthen as it passes over warm water.
Calling the intensification "astounding," NHC forecasters said Thursday morning that there is "a 70 percent chance of Harvey's winds increasing by 45 kt [some 50 mph] over the next 36 hours."
As of Thursday morning, Harvey was moving north-northwest at nearly 10 mph and was expected to turn toward the northwest later in the day.
The deepest storm surge will hit the coast near the center of the landfall and to the northeast, "where the surge will be accompanied by large and destructive waves," federal forecasters say.