CHICAGO - The Midwest and the Eastern Seaboard are bracing for another blast of below-normal temperatures and heavy snowfall after a few days of temperatures that moved slightly above normal for this time of year.

The National Weather Service says a storm developing over the middle Mississippi Valley as rain late Tuesday will change to snow and move northeastward to the Gulf of Maine by Thursday. It is expected to dump up to 20 centimetres of snow in the Chicago area and northern Indiana and more along the Great Lakes in Ohio, Pennsylvania and upstate New York before dissipating over Canada.

Chicago has already been buried by more than 197 centimetres of snow this winter — fourth most on record dating back to 1884-1885, according to the weather service. The snowfall expected into Wednesday could push the seasonal total into third place, ahead of the 195.5 centimetres total from 1969-1970.

Southeastern Michigan, where up to 23 centimetres is forecast, may come close to breaking a 133-year-old snowfall record. The storm will likely move the Detroit area close to the seasonal snow total of 237.7 centimetres set in 1880-1881, according to the weather service.

Indianapolis was expecting a sharp drop in temperature over a 24-hour period overlapping Tuesday and Wednesday, said Chad Swain, a meteorologist at the National Weather Service.

"We're 68 (20 Celsius) for the high right now," Swain said late Tuesday afternoon. "That's going to quickly change."

The sharp changes in temperatures, with Chicago falling to around -10 C late Wednesday after moving above 10 C Tuesday, has caused some confusion.

"I had a guy in here yesterday asking for salt and right after him a guy wanted mulch. Only in Chicago," said Richard Schauer, owner of Schauer's Hardware in Forest Park.

Schauer said his store, like so many others, is out of salt. And he's not about to buy more just to cover one more — hopefully — snow storm.

"I don't want to be stuck with it. It costs a lot of money and takes up a lot of space," he said.

He did say there are still a few shovels, though the selection is pretty thin.

Jeff Gatewood, who owns Allisonville Nursery in the Indianapolis suburb of Fishers, said the months of snow and cold cut down on winter customers, but in recent weeks many visitors confided that their yearning for spring drove them to stop by the business and take in its house plants and cheery garden items.

"Everybody's got so much pent-up energy, it's going to make for a crazy spring," Gatewood said. "Spring fever is really going to be pretty high this year.

"And we all know the weather's going to hiccup and do this a few times before it straightens out."

___

Associated Press writers Don Babwin in Chicago, Rick Callahan in Indianapolis, David N. Goodman in Detroit and Marc Levy in Harrisburg, Pa., contributed to this report.