A winter storm warning was in effect for parts of the northeast U.S. on Thursday evening and expected to bring a new blanket of snow to the Northeast. The upper Midwest also braced for a deep freeze, forecasters said.
"It's an event that doesn't occur too often," said Joel Burgio, senior agricultural meteorologist at Telvent/DTN, of the extreme cold. Burgio expected strong winds as well, making the air feel even colder.
As Chinese President Hu Jintao dined with Mayor Richard M. Daley in Chicago Thursday night, temperatures in the city were forecast to dip below zero Fahrenheit, with a wind chill of 19 below zero, and gusts as high as 25 miles per hour, according to the National Weather Service.
Burgio blamed the cold snap on a "blocking weather pattern" which is preventing warmer air from moving in from the Pacific, while cold air is being pushed down from Canada.
A snowstorm, meanwhile, was moving across the Tennessee Valley on Thursday and was expected to hit the Atlantic coast by Friday, the National Weather Service said.
Big chill
Boston is bracing for heavy snow of up to eight inches starting early Friday morning, according to the weather service. It is expected to impact the morning rush hour. Snowfall rates of one to two inches per hour are possible.
Snow was also predicted for New York City, where two to four inches could fall overnight.
Winter storm warnings were in effect Thursday for parts of Missouri, including the St Louis area, Indiana and Ohio.
The region will experience "blowing and drifting snow and bitterly cold wind chills by Friday morning," the Weather Service said on its web site.
A Chicago homeless shelter representative said she expects that authorities will be bringing homeless people to the shelter because of the weather.
"If they see someone and it's very cold they put them in the car and bring them here," said Laura Stemberg, assistant to the president of Pacific Garden Mission. She noted that the shelter is always crowded regardless of the weather.
John Miksa, 43, a small business owner in Milwaukee, notices people are griping more about the weather, even though Milwaukee's 19.3 inches of snow so far this winter is about 6 inches below normal for this time of year.
"I notice people seem more sensitive to cold and complain much more," said Miksa. "Even though we had had an easy winter so far people are pretty vocal about what little we've had."

The very cold air will chill the Midwest and then the Northeast over the weekend, with temperatures 10 to 25 degrees below average at times, said Chris Dolce, meteorologist for The Weather Channel.
Some six to 10 inches of snow fell overnight along the Interstate 70 corridor, the Weather Service said. Another one to three inches of snow was expected for Missouri and Illinois, and three to six inches in southern Indiana.
Indiana State Police warned motorists on Thursday that if they abandon their vehicles on the roads because of bad weather they may not find the vehicle when they return later.
"We sympathize with people if their car broke down but we have a bigger concern with public safety," said State Police Sgt. Dave Bursten. He explained that cars are towed because they pose hazards, get in the way of snow plows, and are subject to vandalism.
"You shouldn't be surprised if it's not there," Bursten said.
The storm was likely to hit Pittsburgh late on Thursday, Baltimore, Washington, Philadelphia and New York City early on Friday, forecasters said.
The cold air behind the snowstorm will keep high temperatures on Friday down to the single digits and teens from the upper-Mississippi Valley to the Great Lakes and Ohio Valley, Dolce wrote, also on The Weather Channel web site.
By Saturday, highs will range from the single digits and teens in the interior Northeast and New England to the 20s around New York City, Philadelphia, Baltimore and Washington, DC, wrote Dolce.
Tragedy
Authorities say three people driving through a snowstorm to attend a relative's funeral were killed when their car collided with a semitrailer in western Indiana.
Montgomery County Sheriff's Chief Deputy Ryan Needham says the three died shortly before 10 a.m. Thursday on Indiana 47 near Waveland, 50 miles west of Indianapolis. WISH-TV reported that emergency crews at the scene say the victims were two men and a woman.
Needham told the Journal & Courier of Lafayette that authorities have identified two of the deceased and were still working to identify the third. No names were immediately released.
The driver of the semitrailer was not injured.
The Associated Press contributed to this report.