(CNN) -- Two feet of snow has fallen in western New York and more is coming along the southern shore of Lake Erie from Cleveland, Ohio, to Buffalo, the National Weather Service said Monday.
The heavy snow spread north of Buffalo as well.
"Yesterday morning we had none. So it's quite a transition to go from no snow to all this. When you open the door, it's amazing," librarian Dorothy Valenti told The Associated Press by telephone from Constableville, New York, not far from the east end of Lake Ontario. "It's strange to have a snow day before Thanksgiving."
The latest lake-effect storm dropped 23 inches on Ellicottville, New York, 40 miles south of Buffalo, as of 10:15 a.m. Monday and 20 inches on nearby South Dayton.
"It's not nice," emergency dispatcher Laurie Moore in New York's Cattaraugus County told The AP. "Lots of snow. Roads are snow-covered and slippery."
An additional 6 inches of snow could come by evening, according to CNN affiliate WGRZ-TV in Buffalo.
The National Weather Service posted lake-effect snow warnings from Buffalo to Cleveland, Ohio, through Tuesday afternoon. Watch how heavy snow wreaks havoc in Ohio »
Lake-effect snow occurs when cold air passes over a warmer body of water, in this case Lake Erie, according to the weather service. The cold air sucks up the moisture and heat from the water, dropping it as snow when it moves over land.
Wind and snow showers with temperatures in the 20s are forecast for the NFL "Monday Night Football" game between the Buffalo Bills and the Cleveland Browns, WGRZ reported.
To the south along Interstate 90, shoppers in Erie, Pennsylvania, were preparing for the worst on Sunday. iReport.com: Thunder, lightning accompany snowstorm
"I just went and bought new wipers ... I'm scared!" Angela Gadzek, of Warren, Ohio, told CNN affiliate WJET-TV.
The area could expect as much as a foot of snow before Tuesday, WJET reported.
"Just pray everybody stays safe on the roads, just slow down and use your head," Mark Alexander, of Albion, Pennsylvania, told WJET.
"We're ready, we got steady snow tires on everything, and everything's secure at home," Alexander told WJET.
In Ohio, state transportation officials were concerned about keeping the roadways safe.
Rock salt to clear roads of ice was in short supply, CNN affiliate WKYC-TV reported, and authorities were looking for ways to stretch supplies to counteract escalating prices.
The Ohio Department of Transportation used sensors in the roads to target the worst spots and help plow drivers determine how much salt to use, WKYC reported. They were also wetting the salt before spreading it to prevent it from bouncing off highways, WKYC said.
Three to five inches of snow are expected in northeastern Ohio, for a total accumulation of up to 10 inches, WKYC said. Authorities advised motorists to put off non-essential travel until the snow threat eased.
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