More than 65 million people under winter weather alerts from California to New York

(CNN) -- A powerful, coast-to-coast storm continues to bring dangerous threats of heavy snow and high winds Wednesday, putting parts of more than two dozen states under winter weather alerts as travel conditions began to deteriorate in some areas.

More than 65 million people across 29 states from as far west as California to Minnesota through Maine are under winter weather alerts that warn of severe icing, extreme cold and sleet that are likely to make travel miserable Wednesday and knock out power to some.

The Upper Midwest is expected to bear the brunt of the storm in terms of snowfall totals, with Minnesota's Minneapolis area likely getting more than 20 inches Wednesday and more than 2 feet total over the multi-day storm -- potentially the most in 30 years.

The "historic" three-day storm "will bring widespread accumulating snow, with blowing and drifting snow mainly Wednesday through Thursday," the National Weather Service in the Twin Cities said.

The worst impacts over the Twin Cities region -- which generally includes the cities of Minneapolis, St. Paul and their surrounding suburbs -- are expected to begin late Wednesday into Thursday. Heavy snow is expected to blanket the grounds fairly quickly -- and be accompanied by gusty winds, making traveling a life-threatening task for thousands.

Gov. Tim Walz directed the state's National Guard, the transportation department and the state patrol to be prepared to respond storm impacts, he said on Twitter.

"We're working to ensure we're ready -- and Minnesotans have a part to play, too. Plan ahead, drive safe, and limit travel," Walz wrote.

More than 700 flights scheduled for Wednesday in the US have been canceled, according to the tracking site FlightAware. Among those, Minneapolis tallied more than 300 arriving and departing flight cancellations and Denver had nearly 200 cancellations.

The cancellations come as more than five million people are under ice storm warnings across northeastern Iowa, southern Wisconsin, northwestern Illinois and southern Michigan. And more than two million people are under blizzard warnings across parts of Wyoming, Minnesota, Wisconsin and the Dakotas.

Farther west, strong winds from the powerful storm tore down power lines, knocking out power to more than 140,000 homes and businesses in California, where the reported outages occurred in the northern counties of the state including San Mateo, Santa Clara and Santa Cruz, according to the tracking site Poweroutage.us.

California is still bracing for several feet of snow expected in the mountains with a few inches possible in lower elevations,the National Weather Service in Los Angeles said. The unseasonable weather for the Golden State comes nearly two months after rounds of deadly flooding battered many areas.

"Now is the time to prepare for a COLD AND DANGEROUS winter storm expected for much of the week," the National Weather Service in Los Angeles said. "Gusty and potentially damaging winds are also expected."

Storm's path Wednesday

Parts of the Upper Midwest could see snow fall at a rate of 1 to 2 inches per hour, combined with wind gusts of 40 to 50 mph, the National Weather Service said. That unrelenting double whammy is set to create whiteout conditions due to falling and blowing snow.

Those expected conditions have put more than two million people are under blizzard warnings across parts of Wyoming, Minnesota, Wisconsin and the Dakotas.

• Minneapolis: The city could pick up between 15 and 25 inches snow by Thursday. That would be in addition to the 1 to 3 inches that have already fallen there.
• Sioux Falls, South Dakota: In addition to the up to 4 inches of snow the state has already seen, snowfall up to 16 inches and winds of 45 mph are also expected.
• Cheyenne, Wyoming: Heavy snowfall up to 1 foot expected in addition to high winds that could feel as cold as 35 below zero.
• Potentially dangerous icing: Milwaukee in Wisconsin and Detroit and Ann Arbor in Michigan are likely to experience icing beginning Wednesday.
• Severe thunderstorms: Damaging winds and rain are expected Wednesday morning through the afternoon in parts of Oklahoma into western Arkansas, across Missouri and western Illinois, according to the National Weather Service.

Wednesday's expected conditions have spurred states to take safety measures.

South Dakota's governor announced Tuesday the closures of state government executive branch offices Wednesday in more than half of the state's 66 counties, with plans for employees to work remotely. Additionally, Interstates 29 and 90 partially closed Tuesday night to prepare for the expected snow.

Meanwhile in Wyoming, several institutions decided to shutter their doors Wednesday.

Eastern Wyoming College announced the closure of its main campus. The Natrona County school district in Casper will conduct a virtual learning day Wednesday due to hazardous weather and road conditions throughout the area, the district said.

The Food Bank of Wyoming, which says it serves all 23 counties across the state, planned to close Wednesday, it said in a tweet.