(CNN) — Two powerful storms are leaving much of the United States struggling with blackouts, whiteouts and gusty winds on Thanksgiving Day -- and the nightmare could continue in some areas into the holiday weekend.

By early Thursday, more than 200 flights had been canceled in the United States and nearly 2,000 delayed, according to FlightAware.

And the weather pattern promises to stay active, the National Weather Service said.

"Widespread winter weather, flash flood and wind watches, warnings and advisories are currently in effect ... across large portions of the nation," the agency said.

Nearly 300,000 homes and businesses were without power Wednesday night nationwide, mainly in Michigan, Ohio and California, according to utility tracking site PowerOutage.us.

The weather has been so chaotic, 32 states at one point were under some sort of watch, warning or weather advisory. One system pounded Western states with rain along the coast and heavy snow in the mountains, while an East Coast storm dumped snow as its high winds knocked out power.