In this Jan. 9, 2014 photo, ice floes cover the surface of the Hudson River off the west side of Midtown Manhattan in New York. After record-breaking cold sent the city into a deep freeze early in the week, temperatures climbed back into the 30's by Friday.

With the polar vortex subsiding, a natural phenomenon known as "steam-fog" can be seen over the Great Lakes as cold air passes over warm water.

The U.S. side of the Niagara Falls is pictured in Ontario, Jan. 8, 2014. The frigid air and Polar Vortex that affected about 240 million people in the United States and southern Canada will depart during the second half of this week, and a far-reaching January thaw will begin, according to AccuWeather.com.

A man braves the cold and walks along the shore of Lake Michigan as temperatures remain in the negative digits on January 7, 2014 in Milwaukee, Wisconsin.

Frost is shown on a bus stop in Detroit, Jan. 7, 2014.

Ice forms on an abandoned dock structure in the East River due to unusually low temperatures caused by a Polar Vortex in New York January 7, 2014.

Morning commuters bundle up against the cold on the morning of January 7, 2014 in New York.

Ice builds up along Lake Michigan at North Avenue Beach as temperatures dip well below zero, Jan. 6, 2014, in Chicago.

Mist rises from Lake Michigan as temperatures dip well below zero, Jan. 6, 2014, in Chicago.

Bliss Communications maintenance worker Joe Villa shows the results of working outdoors in -17 degree weather, Jan. 6, 2013.

Bill Brasche ski masked begins to fill with snow and ice as he braves the subzero temperatures and bitter wind chills to clear out his driveway, Jan. 6, 2014, in Springfield, Ill.

Bill Brasche braves the subzero temperatures and bitter wind chills to clear out his driveway, Jan. 6, 2014, in Springfield, Ill. A weekend storm dumped up to 15 inches of snow in some parts of Illinois, snarling interstates and shutting down many roads all together.

A woman pushes her daughter and their groceries through blowing snow in the Kroger parking lot in Green Acres Plaza on State Street in Saginaw Township, Mich., Jan. 6, 2014.

A man is silhouetted against the arctic sea smoke rising off Lake Michigan in Chicago, Jan. 6, 2014.

Chris Tinney, 41, removes snow in front of Racquets Downtown Grill and Drs. Gundersen and Zuker's optometrist office on West Western Avenue in Muskegon, Mich., Jan. 6, 2014.

Time and temperature signs agree to the cold temperatures in Lawrence, Kan., Jan. 6, 2014.

Laurel O'Connor works to scrape ice off of her windshield before driving, Jan. 6, 2013, in Bowling Green, Ky.

Two pedestrians go down a street in Chicago's South Loop with temperatures well below zero and wind chills expected to reach 40 to 50 below, Jan. 6, 2014, in Chicago.

Four homeless men warm themselves on a steam grate by the Federal Trade Commission, blocks from the Capitol, during frigid temperatures in Washington, Saturday, Jan. 4, 2014.

Sunlight streams through the windows of a building which caught on fire in Plattsmouth, Neb., Friday, Jan. 3, 2014, and the water sprayed on it by fire fighters froze. Much of the American northeast and the midwest are suffering from sub-freezing temperatures.

Waves crash against the sea wall near high tide in Scituate, Mass., Friday, Jan. 3, 2014.

Sonja Keller walks her dog along the shore in Scituate, Mass., Friday, Jan. 3, 2014. (AP Photo/Michael Dwyer)

A view of the flooding in Scituate, Mass., Jan. 3, 2014.

A view of the flooding in Scituate, Mass., Jan. 3, 2014.

A view of the flooding in Scituate, Mass., Jan. 3, 2014.

A view of the flooding in Scituate, Mass., Jan. 3, 2014.

A view of the flooding in Scituate, Mass., Jan. 3, 2014.

Wilkes-Barre Area School District employee Bob Nahill clears a sidewalk in front of Coughlin High School, Jan. 3, 2014 in Wilkes-Barre, Pa. Northern and eastern Pennsylvania saw 6 to 8 inches of snow, while southern and western Pennsylvania saw 2 to 5 inches, the National Weather Service said.

Heavy surf breaks over the seawall after a winter storm, Jan. 3, 2014, in Hampton, N.H.

Bicycles are covered in snow at Rockefeller Center, Jan. 3, 2014, in New York, the morning after the first major snowstorm of the winter.

A woman is bundled up against the cold in Boston, Jan. 3, 2014. A heavy snowstorm and dangerously cold conditions gripped the northeastern U.S. on Friday, delaying flights, paralyzing road travel and closing schools and government offices across the region.

Sanitation trucks outfitted with snow plows clear Fifth Avenue of snow, Jan. 3, 2014, in New York. A winter storm that swept across the Midwest this week blew through the Northeast and its biggest cities on Friday, producing more than a foot of snow in spots, giving rise to wind gusts that threatened trees and power lines, and leaving bone-chilling cold in its wake.

An Amtrak train kicks up fresh snow as it speeds southbound, Jan. 3, 2014, in Schodack Landing, N.Y. The National Weather Service has posted winter storm warnings through Friday morning in most of the state. Temperatures are in the single digits or below zero, with the wind making it feel as cold as 20-30 below zero in some areas.

A pedestrian uses cross-country skis along East 58th Street during his morning commute, Jan. 3, 2014, in New York.

A tattered flag flies by a flooded yard along the shore in Scituate, Mass., Jan. 3, 2014. A blustering winter storm that dropped nearly 2 feet of snow just north of Boston, shut down major highways in New York and Pennsylvania and forced U.S. airlines to cancel thousands of flights nationwide.

Postal Service letter carrier Danny Kim clears off snow and ice as he climbs on the hood of his mail delivery truck in the parking lot of the Post Office in Bethesda, Md., Jan. 3, 2014. Kim said that despite the storm resulting in many closings of local school systems, he and his colleagues were working on an unchanged schedule.

New York City Mayor Bill de Blasio shovels the sidewalk in front of his house in New York, Jan. 3, 2014. New York City public schools were closed Friday after up to 7 inches of snow fell by morning in the first snowstorm of the winter. It the first test for the new mayor hours after he was sworn in.

Workers clear sidewalks of snow on Fifth Avenue, Jan. 3, 2014, in New York.

A man plows snow in a parking lot following an overnight snowstorm that hit the northern New Jersey region, Jan. 3, 2014, in Jersey City, N.J. New Jersey Gov. Chris Christie declared a state of emergency Thursday, urging residents to stay home. Schools were closed as temperatures dipped below 20 degrees, with wind-chills below zero in some places.

Snow blankets the grounds outside the U.S. Capitol, Jan. 3, 2014, in Washington, following a snowstorm hit the Northeast.

Pedestrians brave wind and snow as they cross Fifth Avenue, Jan. 3, 2014, in New York. A winter storm slammed into the U.S. Northeast with howling winds and frigid cold, dumping nearly 2 feet of snow in some parts and whipping up blizzard-like conditions Friday.

Firefighters shovel snow in front of their firehouse in the Brooklyn borough of New York, following a winter storm that left up to 7 inches of snow, Jan. 3, 2014.

A woman works to dig a car out of the snow during a winter storm in Boston, Jan. 3, 2014. A major snowstorm producing blizzard-like conditions brought bone-chilling temperatures and high winds from the lower Mississippi Valley to the Atlantic coast, with nearly 2 feet of snow falling in some areas of Massachusetts.

A snow plow pushes snow through Times Square in New York, Jan. 3, 2014. The governors of New York and New Jersey declared a state of emergency and urged residents to stay indoors as a major storm, called Hercules by local media, hit the northeastern United States, bringing heavy snow and delaying or cancelling thousands of flights.

A pedestrian takes a photograph under falling snow in Times Square, Jan. 2, 2014, in New York. The storm is expected to bring snow, stiff winds and punishing cold into the Northeast.

Snow accumulates on an NYPD officer in Times Square, Jan. 2, 2014, in New York. The snow storm is expected to bring snow, stiff winds and punishing cold into the Northeast.

People walk through a cold and snowy Washington Park, Jan. 2, 2014, in Albany, N.Y. Up to 5 inches of snow already had fallen in eastern New York by Thursday morning, but the National Weather Service said some areas from Buffalo to Albany could get a total of up to 14 inches by the time the coastal storm moves out Friday morning.

Highway crews work to clear snow from roads, Jan. 2, 2014, in Henniker, N.H. About 6 to 10 inches of snow is expected in the southern half of New Hampshire, and up to a foot in the Seacoast area. The storm is expected to last into Friday morning.

Law enforcement, fire and rescue workers prepare to remove an injured passenger from a car that was in an accident involving a tractor-trailer, Jan. 2, 2014, near Winchester,Va., as snow fell in the northern Shenandoah Valley.

Snow accumulates on the tinted windows of a bus stop, Jan. 2, 2014, in Portland, Maine. Blizzard-like conditions with a wind chill factor of minus 30 degrees are expected before the storm clears out on Friday.

A worker at a Pennsylvania Department of Transportation facility dumps salt into a truck as preparations are made for an expected winter storm, Jan. 2, 2014, in Philadelphia.

Maintenance worker Joe Ehrenberg uses an Unimog to clear snow from a ramp at the Southwest Michigan Regional Airport, Jan. 2, 2014, in Benton Harbor, Mich.

A horse grazes among snow-covered trees at a farm along Red Arrow Highway in Benton Harbor, Mich., Jan. 2, 2014.

Tim Johnson, left, and Michael Bennett clear the snow from the sidewalks and steps around St. James Lutheran Church, Jan. 2, 2014, in Lafayette, Ind. North central Indiana was blanketed on Thursday by several inches of snow.

Emergency workers respond to a vehicle that slid off the road on Interstate 94 near Kalamazoo, Mich., Jan. 2, 2014. A multi-day storm dropped up to a foot of snow on parts of Michigan, causing crashes and spinouts on roadways. Snowfall began Tuesday and continued Thursday morning.

Two-month-old Jack Hsi takes a nap sheltered in his baby carrier while snow falls in Boston, Jan. 2, 2014. Up to 14 inches of snow is forecast for the Boston area.

A snow tuber enjoys a slide down the "Monster Sled" adjacent to the left field wall at Fenway Park as snow falls in Boston, Jan. 2, 2014.

Connecticut Department of Transportation plows clear snow off of Route 183 in Torrington, Conn., Jan. 2, 2014. As much as a foot of snow or more was forecast for some areas in the Northeast overnight Thursday into Friday, and temperatures were expected to plummet, with some areas seeing highs just above zero, according to the National Weather Service.

Elaine Gronewald, foreground, and Cory Bachesta help a stranded motorist on a slippery and hilly portion of road, Jan. 2, 2014, in Kirkwood, Mo. Snow began falling Wednesday and continued into Thursday morning, coating the ground with 2- to 5-inches.

Handyman Warren Page uses a snow blower on the sidewalk outside Lamb's Bride Child Care Center, Jan. 2, 2014, in St. Louis.

Morning commuters walk against blowing snow, Jan. 2, 2014, in Chicago. As much as a foot of snow or more was forecast for some areas in the Northeast overnight Thursday into Friday, and temperatures were expected to plummet, with some areas seeing highs just above zero, according to the National Weather Service.

Naoom Haimson walks his dog, Molly, on the snow-covered Monon Trail in Carmel, Ind., Jan. 2, 2014. Over 5 inches of snow fell in Central Indiana.

Ethan Hays, 8, sleds face down a hill in Indianapolis, Jan. 2, 2014. Over 5 inches of snow fell in Central Indiana.

Cars are covered by snow in a rental car parking lot at O'Hare International Airport in Chicago, Jan. 2, 2014. Another one to three inches of snow could fall across the Chicago metro area today with even more falling in the southern part of the region, according to the National Weather Service.

A pedestrian walks past a replica of the Fenway Park scoreboard during a winter snowstorm in Lawrence, Mass., Jan. 2, 2014.

Christina Kistler walks her dog Sheldon in the snow, Jan. 2, 2014, in Albany, N.Y. Snow and bone-chilling temperatures are greeting morning commuters across New York on the first work day of 2014, with some upstate areas expected to get more than a foot of snow by the weekend.

A pedestrian walks in the snow, Jan. 2, 2014, in Albany, N.Y.

A pedestrian walks through the snow outside the state Capitol, Jan. 2, 2014, in Albany, N.Y.

Commuters drive on snowy road in Chicago, Jan. 2, 2014.

Travelers walk to a train station in a parking lot at O'Hare International Airport in Chicago, Jan. 2, 2014.

A Frontier airlines plane waits for passengers at O'Hare International Airport in Chicago, Jan. 2, 2014.

A van is pulled from a ditch along Interstate 94 near U.S. Route 127 in Jackson, Mich., Jan. 2, 2014.