Strong storms dumped more than a foot of rain in Central Texas, prompting officials to rescue people from trees and cancel classes in a few Austin-area school districts.

The National Weather Service reported significant flooding in the Austin area — Hays, Travis and Williamson counties. Wimberley, a town in Hays County of about 2,600 residents, had received up to 14 inches of rain since Wednesday, NWS meteorologist Steve Smart said.

"It looks to be one of the worst areas with the heaviest rainfall totals," Smart said as storms began moving out of the area Thursday.

To the southeast, Houston motorists were slowed Thursday morning by heavy rain, which caused flooding in some areas. A flash flood warning was issued until midday Thursday for parts of Southeast Texas, including Beaumont.

Emergency rescues were needed in the pre-dawn hours in rural Hays County. A helicopter plucked four people from trees near Buda, said Warren Hassinger, a spokesman for Austin-Travis County Emergency Medical Services.

"It looks like the mission completed, they apparently were able to get those people hoisted," Hassinger said. He had no further details about the rescue.

The Hays County Sheriff's Office had no reports of injuries related to the storms, Deputy Tom Ormsby said.

Austin Energy reported nearly more than 12,000 customers without electricity on Thursday.

Wimberley Independent School District canceled classes Thursday because of "extreme weather conditions," the district said on its website. Neighboring schools in San Marcos and Lockhart also called off classes amid the bad weather.

As many as 3,000 people heeded evacuation requests in San Marcos, 30 miles south of Austin, where emergency personnel went door-to-door Thursday urging residents to leave before floodwaters from the Blanco River reached the San Marcos River, police Chief Howard Williams said.

"We're anticipating some serious flooding," Williams said. "We've been trying to get ahead of the game, getting as many people out of these low-lying areas as they can."