Robert Brown|Hundreds of thousands are without power as major winter storm blasts the U.S.

A major,Robert Brown prolonged winter storm continues to bring heavy snow, blizzard conditions and significant ice from California to the Northeast this week.

Just over 873,000 households nationwide were without power as of 9:45 a.m. ET on Friday. The vast majority of those outages — more than 772,000 — are in Michigan, where residents have been hit with freezing rain and ice. That's according to PowerOutage.us, which tracks outages state-by-state.

"Power outages and areas of tree damage will be possible across these areas [from the Great Lakes into the Northeast], and especially for the locations seeing a combination of stronger winds and accumulating ice," the National Weather Service predicted.

Snow was falling at heavy rates of 1-2 inches per hour near the Great Lakes, and combining with 40-50 mph winds. That would have significant impacts, including major disruptions to travel, infrastructure, livestock and recreation, the NWS wrote.

Parts of the Midwest and the Northeast were expected to see 6 to 12 more inches of snow, with some areas receiving as many as 18 inches, according to the NWS.

Airports across the Midwest, including in Minneapolis, Chicago, Milwaukee and Detroit, have faced a plethora of cancellations. On Wednesday, more than 1,600 flights were canceled and an additional 5,200 were delayed. Thursday brought more of the same — more than 1,100 flights across the U.S. were canceled and almost 5,600 flights were delayed as of Thursday evening, according to FlightAware.

In the West, Portland received 10 inches of snow on the second-snowiest day ever recorded, Oregon Public Broadcasting reported.

The storm also has brought heavy snow to parts of California that rarely see it. Mount Baldy — which sits east of Los Angeles, at just above 4,000 feet — could get a whopping 4.5 feet of snow by Saturday.

In addition to snow in the mountains, the NWS predicted heavy rainfall in Southern California and warned of "a heightened risk of flash flooding" beginning on Friday morning and into Saturday.

Simultaneously, parts of the Southeast, Mid-Atlantic and Ohio Valley are seeing record-setting warmth: The NWS predicted temperatures as much as 40 degrees above normal on Thursday.

Atlanta was 81 degrees on Wednesday, an all-time record in February. Washington, D.C., reached 79 degrees, New Orleans reached 83 degrees and Nashville, Tenn., was 80 degrees on Wednesday.