Deep freeze thaws out as weekend warmth settles in: The latest forecast

After days of dangerously cold wind chills, the country is about to get hit with a major warm up this weekend -- including feeling up to 100 degrees warmer from Minneapolis to Chicago and all the way to New York City.

A historic cold blast

At least 18 people have died, including a student at the University of Iowa, in the spate of bitterly cold weather across the Midwest and Northeast this week, according to The Associated Press.

During the polar invasion, more than 340 cold temperature records were broken or tied in the Midwest.

The coldest readings were in northern Minnesota, where two sections of the region were hit with a bone-chilling minus 56 degree temperature and minus 66 degree wind chill.

Chicago was below zero degrees for 52 consecutive hours -- the fourth-longest streak of below zero on record.

The frigid takeover paralyzed cities from Chicago to Buffalo, New York, impacting airports, roadways and schools.

At a Brooklyn, New York, jail, federal inmates were shivering in their cells as the facility went days without heat or electricity, according to Benjamin Yaster, an attorney with the Federal Defenders of New York.

Yaster said after a fire at the jail, his client was left in the dark in his short-sleeved jumpsuit without extra blankets or clothes.

New York City reached a temperature of 2 degrees on Thursday -- the city's coldest day in three years.

Weekend warmth

Coming in after the arctic blast are temperatures that will feel 50 to 100 degrees warmer this weekend and into early next week in Minneapolis, Chicago and New York City.

Just days after wind chills in Chicago and Minneapolis were minus 50 degrees, the temperatures will climb back up to nearly 40 degrees in Minneapolis and over 50 degrees in Chicago.

From Washington, D.C., to Boston, temperatures will soar to the mid to upper 50s -- above normal temperatures for early February.

But don't let your guard down: major temperature swings can lead to ice jams, flooded rivers, potholes and burst pipes.

West Coast storms

Meanwhile, a series of strong storms will hammer the West Coast, especially California, through the weekend.

The strongest storm will move in Friday night, dumping heavy rain and heavy mountain snow across California through Saturday.

Some areas in central and southern California could see 4 to 7 inches of rain and flash flooding from San Francisco to Los Angeles.

Rainfall rates could climb to over 1 inch per hour in the Santa Barbara and Ventura County areas.

The rain is expected to hit recent burn areas, which could trigger mudslides.

ABC News' Aaron Katersky contributed to this report.