BOSTON (AP) — Frigid temperatures descended on the northern tier of the U.S., as a biting chill followed a powerful snowstorm from the central Midwest into the Northeast, prompting warnings of "flash freezing" along the East Coast.

According to the National Weather Service, people from Montana to Maine are dealing with sub-zero degrees Fahrenheit (-18 Celsius) wind chill temperatures.

The arctic blast brought frigid wind chills to parts of Pennsylvania, New York and the northern New England region.

Earlier, the snowstorm, which dumped more than 19 inches (about half a meter) of snow on Chicago and more than a foot (about a third of a meter) on southeastern Wisconsin, deepened off the southern New England coast. It brought accumulations approaching 18 inches in the Boston area and around a foot of slushy wintry mix to Hartford, Connecticut, Providence, Rhode Island, southern New Hampshire and Vermont — places still reeling from the up to 3 feet (about a meter) they got last week.

New York City's snow totals ranged from around 3.6 inches (9 centimeters) in Central Park to 7 inches (17.78 centimeters)in the Bronx.

As Boston recovers from its second major winter storm in a week, Mayor Martin J. Walsh announced the victory parade for the Super Bowl champion New England Patriots football team would be postponed until Wednesday morning.

School was canceled in Boston and some suburbs for Tuesday and Gov. Charlie Baker ordered a delayed start for nonessential state agency workers to allow more time for clearing roads.

The storm was blamed for at least one death, a woman who was struck and killed by a snowplow in suburban Boston.

Doctors in Ohio said Toledo Mayor D. Michael Collins was heavily sedated and in critical condition Monday, a day after he went into cardiac arrest and his vehicle crashed into a pole on his way home not long after a news conference.

The storm delayed two of America's biggest court cases — the murder trial of former New England Patriots star Aaron Hernandez and jury selection in the federal death penalty trial of Boston Marathon bombing suspect Dzhokhar Tsarnaev.

Testimony was to resume Tuesday in the Hernandez trial. But federal court officials in Boston, who follow the city's school closure schedule, said the Tsarnaev proceedings would be delayed a second day.