Tropical Storm Bill, which formed in the Gulf of Mexico, weakened to a depression late Tuesday and continued to bring heavy rain in central Texas, raising flood threats. The center of the depression was located about 40 miles of Austin, the National Hurricane Center said.

A tropical storm warning, in effect since Monday, was canceled late Tuesday. Bill was moving toward the north with a speed of 13 mph and was expected to continue in the direction on Wednesday, later turning to the northeast on Thursday. The storm, which had maximum sustained winds of 50 mph, reduced to near 35 mph with higher gusts, the center said. Forecasters said that the system is expected to weaken further in the next 48 hours.

The National Hurricane Center also said that Bill is expected to dump 4 to 8 inches of rain over eastern Texas and eastern Oklahoma and 3 to 6 inches over western Arkansas and southern Missouri. A few tornadoes were also expected to occur over parts of east-central Texas through Wednesday morning.

Flood watches were in place from southeastern Texas through eastern Oklahoma and southern Illinois, the center said earlier.

Bill, which made landfall along the Texas coast on Matagorda Island on Tuesday, left more than 13,500 people in eastern Texas without electricity.

The storm comes even as the state recovers from last month's record rainfall that triggered floods and killed at least 23 people.