Parts of the midwest were bracing for blizzard conditions on Tuesday morning as a powerful winter storm continued east, knocking down power lines and shutting down major highways.

The National Weather Service issued winter storm or blizzard warnings in portions of nine states and wind advisories in several more as the storm brought more heavy snow to the nation.

Radar showed precipitation falling over Nebraska, Iowa, Illinois and Minnesota on Tuesday morning. The storm was expected to reach Wisconsin and northern Michigan this afternoon.

Blizzard warnings were issued in parts of Minnesota, Iowa, South Dakota, Nebraska and Kansas.

The National Weather Service warned that those areas could receive between six to 15 inches of snow and wind gusts of up to 50 mph, which could reduce visibility and lead to road closures.

Notably, a roughly 300-mile stretch of Interstate 70 between Denver International Airport and Hays, Kansas, was closed, according to the Colorado and Kansas transportation departments. A 225-mile stretch of U.S. 36 that largely parallels the interstate highway was also closed down.

The Colorado Department of Transportation blamed the closures on “whiteout conditions.” The National Weather Service said one mountainous part of the state received 33 inches of snow.

The Weather Channel is referring to the storm as Winter Storm Kayla.

Portions of Colorado and Wyoming were under winter storm warnings, as were other parts of the five states in which blizzard warnings were issued. The storm wasn’t expected to bring snow to the south, though the National Weather Service issued wind advisories in parts of Kansas, Missouri, Oklahoma, Texas, Arkansas, Illinois, Indiana, Kentucky, Tennessee, Alabama, Mississippi and North Carolina because strong sustained winds were expected in those regions.

Some states should expect severe thunderstorms, the National Weather Service warned, and there was a possibility that tornadoes could touch down in Alabama, Mississippi and the Ohio River Valley later tonight. The service had yet to issue any thunderstorm or tornado watches.

Residents of all of the above states are encouraged to monitor their local forecasts.

The storm has already brought wind gusts of at least 70 mph to six states, according to the National Weather Service, including 90-mph-plus gusts in Texas, California and New Mexico.

About 143,000 people in Southern California were without power on Sunday, according to local utility companies Southern California Edison and the Los Angeles Department of Water and Power, though those numbers were down to about 12,000 as of early Tuesday morning.

The National Weather Service reported that gusts reached 40 mph in Nebraska, and parts of the state received between seven and 12.5 inches of snow as of 8 a.m. Tuesday. More was expected.

The Omaha Public Power District said about 20,000 customers were without power, while the Lincoln Electric System said it was working to turn the lights back on for about 1,800 customers.

The Nebraska Department of Transportation said it closed a 112-mile stretch of Interstate 80 between Kearney and York, and several other state routes were impassible or fully covered.

Some parts of Kansas received 10 inches of snow as of Tuesday morning, the National Weather Service reported. Several state and U.S. highways in the state’s northwest corner were closed to traffic, the state Department of Transportation reported.

More than 130 flights to or from Denver International Airport were cancelled as of mid-day Tuesday, according to flight monitoring website FlightAware.com. The Colorado Department of Transportation said it also closed a 159-mile stretch of Interstate 76 and several state highways.

The storm also brought a foot or more of snow to several locations in Wyoming, according to the National Weather Service, including 24.3 inches near Driggs.

Totals weren’t yet available for Iowa, though the state Department of Transportation reported that a part of Interstate 29 was closed near Sioux City and many roads were fully covered.