Winter ended weeks ago, but blizzard warnings were in effect on Monday for parts of three states across the northern Plains as AccuWeather forecasters warned that a "storm of the century" could unfold across the region this week.
Elsewhere, winter storm warnings and watches dotted the weather map across the northern tier of the United States as a storm system, which came ashore in the Pacific Northwest, was expected to track eastward.
The storm system brought snowfall to Portland, Ore., on Monday, the first time the city has ever recorded measurable snowfall in the month of April, according to AccuWeather meteorologist Renee Duff.
As of Monday morning, 1 inch of snow had been tallied at Portland International Airport. Records there go back to 1940, according to the National Weather Service. Interestingly, the snow on Monday was not even close to the latest snowfall ever recorded in Portland. The city got snow on May 8, 1953, when a half-inch was measured.
Since last week, AccuWeather meteorologists have been monitoring for the potential for a large storm to track from the Northwest through the northern Plains, where it is expected to strengthen quickly, bringing widespread gusty winds, blizzard conditions and substantial snow totals to the northern Plains.
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| AccuWeather mosaic radar where the greens and yellows show rain showers and heavy rain, while the light and dark blue show light to heavy snow taken Monday morning. Image courtesy of AccuWeather |
There is the potential for this storm to bring record snowfall for the month of April to cities such as Bismarck and Grand Forks, N.D. A record-setting, late-season snowstorm in 1966 unloaded up to 2 feet of snow to these areas, and similar totals are expected from this week's storm, making it likely this will rank as "one of the worst storms in recent history," AccuWeather senior meteorologist Adam Douty said.
The combination of high winds and snow will shut down roads and interstates across many areas, and snowdrifts may reach up to 20 feet.
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The large storm is expected to move east from the Rockies into the center of the country Monday night into Tuesday, where it will clash with warm, humid air in the East from the Gulf of Mexico, serving as the storm's moisture source. Meanwhile, a southward dip in the jet stream will allow cold Canadian air to filter into the Southwest, the Rockies and northern Plains, setting the stage for a more robust amount of snow as the week progresses.
On the northwest side of the storm, heavy accumulating snow is likely to begin on Monday night and continue through Thursday, especially for portions of the northern Plains into the Canadian Prairies.
Areas in the northern Plains and high terrain of the Rockies can pick up more than a foot of snow. Winds are expected to be strong enough to produce blizzard conditions later on Tuesday through early Thursday.
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The storm will bring snowfall to an expansive swath of the nation from Idaho and Utah across western Nebraska into the Arrowhead of Minnesota by the time the storm is over. Those places that don't get the heaviest accumulation totals are expected to pick up a few inches of snow.
The exact track of the storm will determine where the heaviest snow extends from the Rockies to the northern Plains. However, communities from Bismarck, N.D., to Winnipeg, Manitoba, and well into Ontario, could receive over 18 inches of snow with 2 to 3 feet in spots.
"In the hardest-hit areas, people need to plan to be self-sufficient for several days with enough water, food and supplies, as it may take considerable time to clear roadways from the snow that will fall and then blow and drift," AccuWeather chief meteorologist Jonathan Porter said. "Power outages may occur as well, adding more challenges for people in these areas."
In Grand Forks, N.D., the snowiest April ever on record was in 1970 when 17 inches of snow fell. It is not out of the realm of possibility that this snowstorm alone could produce that much snow there. The highest three-day snowfall total ever recorded in South Dakota during the month of April was in Custer, where snow ending on April 20, 1920, piled up to 44 inches.
While the specific track of this system can shift, confidence continues to increase that blizzard conditions will occur from the Front Range of the northern Rockies extending northeast through the Dakotas into northwestern Minnesota.
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It is possible that the storm could far exceed the blizzard criteria of one-quarter mile visibility or less with winds of 35 mph or greater for three consecutive hours. Should the storm develop to its full potential, gusts may be as high as 50 mph resulting in near-zero visibility for hours in some cases over parts of the northern Rockies and Plains.
Heavy snow rates of up to 2 inches per hour can impact the Dakotas on Wednesday as the storm rapidly deepens in the region. This alone can lead to serious difficulty for road crews to keep transportation routes clear. There is the potential for major state routes and interstates, such as Interstates 94 and 90, to be closed for extended periods of time.
In addition to heavy snow, the strong storm will lead to increasingly gusty, northerly winds. The presence of such heavy snow can lead to very low visibility, as well as significant drifting of snow, further increasing the potential impacts to the region.
"The snow will be stickier than usual," AccuWeather meteorologist Matt Benz pointed out, referring to the consistency of snowfall that occurs in the northern Plains during January and February. He said the comparatively higher temperatures present during this storm will cause snow to "stick to everything adding extra weight to power poles and trees."
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| Snowfall amounts from the Blizzard of April 1997. |
With strong winds, this extra weight can make these objects more susceptible to breaking. The blizzard of April 1997, which pummeled parts of North Dakota with as much as 20 inches of snow, knocked out power for thousands of people and made travel difficult, if not impossible, for several days.
Motorists are highly encouraged to stay clear of these routes and avoid driving at all costs as getting stranded in the heavy snow and near-zero visibility is possible, leading to a life-threatening situation.
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In addition to the high winds and heavy snow, it's going be very cold in the places that are hit by the storm and feel even colder than it is. In Bismarck, for example, AccuWeather is calling for the temperature to top out at 26 degrees and dip to 21 at night on Wednesday.
However, it will feel lower than 12 degrees and will plunge to 3 degrees below zero at night. This will feel especially brutal given that the high temp on Saturday hit 64 degrees and the last time the high temperature didn't reach at least 50 there was on April 3, when the mercury topped out at 40.
Similar conditions are expected in Grand Forks, though even at its lowest, it should feel like above zero there on Wednesday.
This time of year is a particularly sensitive one for cattle ranchers in the northern Plains. Calving season is underway in this region and any significant snowfall can pose a serious threat to the lives of young cattle if they become buried for any extended amounts of time. The blizzard of April 1997 killed an estimated 100,000 cattle in North Dakota.
At the same time, snow is flying and cold winds are howling over the northern Plains and Rockies, a significant outbreak of severe weather will ramp up farther to the south and east over the Plains and Mississippi Valley.
The storm is expected to lose strength later on Thursday, leading to improving conditions through the day in the northern Plains as the storm shifts east.
