A massive winter storm moving across the U.S. Midwest knocked out power to more than 250,000 customers in Michigan and Wisconsin on Friday ahead of a brutal freeze expected to blanket the region starting this weekend.

Some 151,203 homes and businesses were without power in the Michigan, according to data from PowerOutage.US, a website that tracks, records and aggregates data on power outages in the U.S.

In Wisconsin 102,692 customers were without power by midnight Friday.

Airlines delayed more than 7,600 flights across the U.S. on Friday, including planes grounded at Chicago's O'Hare International Airport, due to winds and blinding snow.

In Iowa, Republican presidential candidates canceled events three days out from the state's caucuses, the first of the state-by-state contests in which parties pick their nominees for November's election.

Extreme weather is a reminder of the February freeze in 2021 that left millions in Texas and other central states without power, water and heat for days, and a winter storm in December 2022 - known as Elliott in the energy industry - that almost caused the collapse of power and natural gas systems in parts of the eastern half of the country.

The storm is coming ahead of what will likely be the nation's coldest weather since December 2022, according to data from financial firm LSEG.