OSWEGO, N.Y. (AP) - While the northern Plains and Northeast shiver in dangerously cold temperatures, the folks in upstate New York are keeping warm shoveling snow - lots of snow.

Since Sunday, the small towns of Parish and Mexico have recorded more than 6 feet of snow, and forecasters with the National Weather Service say it isn't over yet.

Another 2 feet or more of heavy lake effect snow was expected Thursday for the communities along eastern Lake Ontario, and more squalls are likely through the weekend.

"We're just trying to keep up. It's almost an unreal amount," said Mayor Randy Bateman of Oswego, where 70 inches of snow had fallen by Thursday morning. "We catch up when it stops, but then it just comes again, even heavier."

Whiteout conditions - the snow has been falling at a rate of 5 inches an hour at times - forced state police to temporarily close Interstate 81 between Central Square and Pulaski, a stretch of about 15 miles. Travel advisories against unnecessary travel were posted for Oswego and its neighboring counties. Mexico officials renewed a snow emergency declaration, and many government offices were closed.

Schools were closed for a fourth day in Oswego and Mexico.

In West Virginia, where as much as 9 inches of snow has fallen, some schools that had been closed were able to reopen on Thursday, but in most of the state, classes were still delayed, and in a few counties, canceled. Officials had to call snowplow drivers out of retirement Wednesday to clear the roads.

The weather also disrupted travelers, leaving some stranded overnight in airports in the Midwest after flights to the Northeast were disrupted.

Temperatures in the Northeast were inching back up to something closer to normal for this time of year, but the upper Midwest and northern Plains still awoke to subzero temperatures Thursday - minus-12 in Minneapolis and 3 below zero in Chicago.

The bitter cold and slippery roads have contributed to at least 19 deaths - five in Ohio, four in Illinois, four in Indiana, two in Kentucky, two in Michigan, and one each in Wisconsin, New York and Maryland, authorities said. Three of them died Tuesday when two SUVs crashed on a slick road in northern Indiana. An autopsy Wednesday determined that an elderly woman found in a New York City building had died of hypothermia.

In Oswego, a big concern was keeping the city's 800 fire hydrants clear, said Fire Chief Ed Geers.

"We're just trying to keep on top of digging out the hydrants. When you get 5 feet of snow in 24 hours, it's tough," Geers said.