Snowstorm, 60MPH Winds Threaten Blizzards Across Plains and Midwest

A "dangerous" winter storm was expected to dump up to 18 inches snow across much of the Plains and the Midwest on Tuesday, with blizzard and white-out conditions forecast for many areas.

Winter-storm alerts were in effect across at least eight states from Wyoming to Michigan, with strong winds likely to snarl travel and make roads hazardous. Some areas could even see lightning and thundersnow, the Weather Channel said.

Heavy snow was affecting Colorado, Nebraska and parts of Iowa early Wednesday. More than 300 flights were already canceled as at 6 a.m. ET, FlightAware reported, with Denver, Colorado, the hardest-hit airport.

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The powerful weather system has already delivered record-setting snowfall in Colorado and triggered 3,400 lightning strikes across Arizona early Monday.

"Blizzard warnings are in effect for northern Kansas, northeast Nebraska, southeastern South Dakota, southwest Minnesota and northern Iowa," Weather Channel lead meteorologist Kevin Roth said.

Minneapolis was forecast to see between 5-8 inches of snow Tuesday, with 11 inches forecast for Omaha, 12-18 inches for Sioux City, Iowa, and "about a foot" across Wisconsin, Roth said.

Thunder and lightning was possible amid the snowfall in parts of Nebraska and Iowa.

Even in areas where snowfall has stopped, such as central Nebraska and northwest Kansas, strong winds gusting up to 60 mph were likely to blow the fallen snow around, leading to ground blizzards.

"That will reduce visibility to very poor, with dangerous driving conditions," Roth said. "In white-out conditions you won't be able to see very far in front of you, if at all."

However, the storm is likely to wind down by the end of Wednesday.