Through this weekend, the first significant arctic outbreak of winter will affect most of the country. Wind, flooding rain, and some tornado warnings have been issued across the U.S.
A storm packing heavy rain was sweeping through the Northeast early Wednesday, while winter weather brought tornadoes in the Midwest and South, flood threats in Florida and blizzards in the Northwest.
Large swaths of the U.S. have faced an intense winter storm over the past several days. Hundreds of thousands were without power and weather advisories were issued across the country.
Heavy snow and high winds are causing blizzard conditions in the Upper Midwest. It's the latest stage of a three-day storm that's placed over half the country under winter weather warnings.
The term forecasters are using to describe the overall weather pattern is "anomalous" — for its unusual cold and warmth. In California, it could be the coldest storm in years.
The weather service said "life-threatening cold temperatures and dangerous wind chills will create a potentially life-threatening hazard for travelers that become stranded" or people who work outside.
Nationwide, thousands of flights were canceled or delayed. In some places, temperatures dropped more than 30 degrees in an hour. Wind chills reached well below zero. Inches of snow fell.
A destructive winter storm marched across the U.S., delivering blizzard-like conditions to the Great Plains hours after tornadoes touched down in parts of Texas, Oklahoma and in Louisiana.
A winter storm packing powerful winds, heavy rain and potentially several feet of snow in the Sierra Nevada shut down highways, toppled trees and triggered flood watches and avalanche warnings.
More than 100,000 homes and businesses lost power and thousands of flights were canceled as states from New Mexico to Maine were placed under winter storm warnings and watches.
The National Weather Service predicts a prolonged, major winter storm that could travel across parts of the Midwest into the Northeast later this week.