More than 1,600 US flights were canceled Wednesday amid winter storms.
About 5,000 US flights were delayed as of Wednesday evening.
Winter storms are hitting parts of the Midwest and Northeast.
California is bracing for another round of strong winter storms.
A rare snowfall warning was issued for Los Angeles on Wednesday.
NBC News reported:
More than 1,500 flights in and out of the United States were canceled on Wednesday as severe weather wreaked havoc with massive storms threatening to bring record snowfall across America.
Residents of the Northern Plains bear the brunt of the storm, with schools across the Dakotas, Minnesota and Wisconsin announcing closures ahead of the severe weather system, which is expected to affect millions, while California struggles with strong winds and widespread power outages.
The National Weather Service issued winter storm, blizzard and high wind advisories for the western and north-central US, with up to 2 feet of snow expected in some areas through Thursday.
According to online flight tracker FlightAware, at least 4,728 flights within, into or out of the United States were delayed as of Wednesday afternoon.
As of 6 pm EST there were 1,556 US flight cancellations and at least 425 trips involving the Minneapolis-St. Paul International Airport. At least 270 cancellations are listed from or into Denver International Airport.
