HOUSTON – Tropical Storm Humberto formed off the Texas coast Wednesday, promising to bring more rain and possibly flooding to a state coming off one of the wettest summers in more than 50 years.

Forecasters warned residents along a 270-mile stretch of coastline extending into southwestern Louisiana to brace for the storm, which was expected to slosh ashore south of Houston overnight Wednesday.

Between 5 to 10 inches of rain was expected, with some spots possibly getting as much as 15 inches. But authorities said evacuations were not necessary.

“This obviously isn’t an evacuation event or hurricane,” said John Simsen, emergency coordinator for Galveston County. “It’s too close to be in a position where it’s going to develop that much.

“However, it looks to be a prolonged rain event and some pretty substantial tropical storm-force winds.”

Texas has had one of the wettest summers on record, with Houston soaked under the most rain it’s had in a summer since 1942.

In Austin, Governor Rick Perry activated 50 military vehicles with 200 soldiers, plus a half-dozen helicopters and two swift-water rescue teams. Other crews from the U.S. Coast Guard were on standby.

“Some areas of our state remain saturated by summer floods, and many communities in this storm’s projected path are at high risk of dangerous flash flooding,” Perry said.

Brazoria County Sheriff Charles Wagner said low-lying areas in his coastal county could present problems for residents and “put water into a lot of houses.” No evacuations, however, were recommended.