BISMARCK, North Dakota — Another day, another Alberta clipper.
The National Weather Service on Thursday morning issued a blizzard warning for eastern North Dakota — the sixth in the region this winter — as gusty winds blew around fresh snow and made travel treacherous.
It's been an active year for blizzards in the Red River Valley, and western and central North Dakota also have experienced several of the winter blasts.
"Blizzards can be rare, but we've had so many of these Alberta clippers coming through this year, and they bring a lot of wind with them," said Nathan Heinert, a National Weather Service meteorologist in Bismarck.
An Alberta clipper is a fast-moving system that moves southeast out of the Canadian province of Alberta and into the Plains, Midwest and Great Lakes regions of the U.S. It typically brings light snow, strong winds and colder temperatures. A series of them blew through the state in January, resulting in five blizzards in eastern North Dakota between Dec. 28 and Jan. 26.
The weather service defines a blizzard as three consecutive hours of visibilities less than a quarter mile, with sustained winds or frequent gusts of at least 35 mph.
Thursday's blizzard was "an Alberta clipper with genuine snow — we've had about 2-3 inches," said Bill Barrett, a weather service meteorologist in Grand Forks. "The combination of fresh available snow with winds in excess of 30 mph has necessitated a blizzard warning for several hours."
The only other winter season in the Red River Valley with more blizzards in a month's time was 1996-97, when there were seven between Dec. 17 and Jan. 21, according to the weather service office in Grand Forks.
The average number of blizzards in the Red River Valley is only about two per winter. The high point was 10 in 1996-97 — the winter preceding historic spring flooding in the valley.
What is known as "meteorological winter" begins Dec. 1 and ends at the close of February, but March typically also is a stormy winter month in the state, and more blizzards are possible this year.
"Things start warming up from south to north and you have more available moisture — even the Gulf of Mexico becomes more of a player," Barrett said. "You have colder air to the north and warmer air to the south, and that generates storm systems."
The state Transportation Department issued travel alerts for the eastern two-thirds of the state Thursday morning because of reduced visibilities. Officials closed Interstate 94 between Jamestown and Valley City for several hours, after numerous vehicles including four semitrailers went in the ditch.
"The roadways were pretty clear — there was no ice," Highway Patrol Capt. Bryan Niewind said. "Visibility was really reduced to where people became disoriented and just drove off the road."
No one was seriously hurt.
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