Updated

After a week of battling snow, rain and floods, Ohio braced for a new series of weather anomalies.

Fog was blamed for one death on Wednesday, the National Weather Service (search) issued a high-wind warning for some portions of the state and freezing temperatures were forecast across Ohio by the weekend.

Melting snow and rain created a thick fog in northwest Ohio, leading to numerous accidents. One person was killed in Defiance in a multi-vehicle pileup, the State Highway Patrol said.

Accidents on secondary roads also forced authorities to shut down some routes. Near the Indiana state line, authorities were diverting traffic away from the Ohio Turnpike (search) because of a crash involving at least 20 vehicles on the Indiana Toll Road (search).

Although the crest of the Ohio River had moved past southwest Ohio, flooding along several other rivers and streams remained a problem. The Great Miami River at Miamitown, just west of Cincinnati, overran its banks, flooding fields and parking lots.

Brian Astifan, of the National Weather Service in Cleveland, said more rain was possible until a cold front comes through the state Thursday.

"A lot of these rivers will remain high until the end of the week," he said.

The weather service also warned that winds of 25 to 35 mph, with gusts up to 60 mph, could accompany showers and thunderstorms in several northern Ohio counties through Thursday evening.

Officials in Tuscarawas County in eastern Ohio asked people and businesses near the Tuscarawas River to voluntarily evacuate Wednesday.

"We've contacted most of the residents who live along the river and advised them all of the situation," said Bryan German, a Dover firefighter.

Nick Krupa, Army Corps of Engineers operations manager, said several Ohio dams managed by the corps had unusually high water levels. Controlled releases were ordered at the Bolivar Dam and Dover Dam in the Tuscarawas River to moderate inevitable flooding that would be worse if water spills over the dams.

Krupa said the Bolivar Dam, an earthen dam, was being closely monitored for seepage that might indicate soil erosion.

In southeast Ohio, Morgan County rescuers needed boats to move 12 people from homes surrounded by water from the Muskingum River, said Keith Spare, spokesman for the county Emergency Management Agency.

Parts of Ohio, West Virginia and Kentucky have been flooded since last week when rain fell on ground already saturated by melted snow.

"Right now we're just worried that the ground is so saturated that any rain we get will just run off to streams and creeks," said John Sikora, a weather service meteorologist in Charleston, W.Va.

More rain was expected in southeast Ohio on Thursday before temperatures plummet from the 60s into the 20s Thursday night, with highs Friday around 30 degrees, Sikora said.

"If there's any standing water around it's going to freeze up," he said.

Floodgates remained up along the Ohio River, including at Cincinnati and nearby Covington, Ky., where the river was at 56.3 feet at midday Wednesday. Forecasters said the Ohio wouldn't drop under its 52-foot flood stage at Cincinnati until sometime Saturday.

Gov. Bob Taft has declared a state of emergency in 56 of Ohio's 88 counties, making them eligible for state assistance cleaning up debris from flooding and ice that knocked down tree limbs and power lines.