Residents nervously watched as rivers continued to rise Thursday from heavy storms that dropped as much as 30 centimeters of rain in the central United States and killed more than 12 people. While rain stopped in Ohio and other states Thursday, authorities warned that many rivers would crest well above flood stage over the next several days. Flooding was reported Wednesday in parts of Arkansas, southern Illinois, southern Indiana, Missouri, and Kentucky. Thursday morning, high water closed a major east-west highway in central Ohio. The flooding was receding by mid-morning, but there was no estimate of when the road would reopen. President George W. Bush declared a major disaster in Missouri on Wednesday night and ordered federal aid to supplement state and local recovery efforts in areas affected by flooding. Seventy counties and the city of St. Louis are now eligible for federal funding for emergency measures. Several areas of Missouri were preparing for record-level flood surges expected to hit Friday and Saturday. Authorities were straining to keep pace with some of the worst flooding in the region in decades. The National Weather Service was predicting record flooding along the Meramec River near St. Louis. Some residents already had been evacuated Thursday. Three rivers in southeastern Missouri also were expected to see significant flooding. Much of Ohio was under a flood warning Thursday. Most of southwest Ohio had received more than 10 centimeters of rain, and officials in some counties were preparing to declare a state of emergency because of the rising waters.