CHICAGO — Rain and rapidly rising temperatures accompanied by thick fog threatened to cause flooding Saturday in the Midwest after days of arctic cold, heavy snow and ice.
Thick ice on roads that contributed to dozens of deaths had thawed, and mountains of snow turned into pools and streams of water.
"We're getting rid of one problem, the ice, but we're getting another problem with the flooding," said Marisa Kollias, spokeswoman for the Illinois Department of Transportation.
The National Weather Service posted flood watches and warnings Saturday for parts of Illinois, Iowa, Wisconsin, Indiana, Michigan and Missouri. As much as 2 inches of rain fell in two hours during the night in west-central Illinois, the National Weather Service reported Saturday.
And as warm air collided with cold, the weather service posted tornado watches for parts of Texas, Oklahoma, Arkansas, Missouri, Illinois and Kansas.
After subzero temperatures in places earlier in the week, Saturday morning readings were in the 40s as far north as Cheboygan, Mich., at the top of the state's Lower Peninsula, the weather service said. However, up to 7 inches of snow is possible in the state today, the agency said.
The weather service said the Chariton River was overflowing and causing minor flooding in Chariton, Iowa. Flood stage is 15 feet; the river was at 16.6 feet at 3 a.m. Saturday and expected to rise a bit more.
Around Chicago, Cook County authorities offered sandbags to communities that needed to fortify low-lying areas, county spokesman Sean Howard said.
Hundreds of people spent the night at Chicago's Midway Airport, where all 82 flights Friday evening were canceled as the thick fog rolled in. There were also more than 400 flight cancellations at O'Hare International Airport, the nation's second busiest.
Operations returned to near normal Saturday at Midway, although 36 flights were canceled because aircraft were out of position following Friday's weather problems. More than 100 flights were called off Saturday at O'Hare.
Temperatures also were rising in the Pacific Northwest, which has been pummeled by deep snow.
In Portland, Ore., rain was expected to wash away much of the 19 inches of snow that by one measurement had made December the city's snowiest month since January 1950.
Slippery roads and cold might be to blame for at least 44 deaths last week: 11 in Indiana; eight in Wisconsin; five each in Ohio and Michigan; four each in Kentucky and Missouri; two in Kansas; and one apiece in Illinois, Oklahoma, Iowa, Massachusetts and West Virginia.