Tis the season of sitting by the fire, drinking hot apple cider and watching the snowflakes falling. With most people experiencing the first snowfall and blizzard this past week, the question for most people is how many more blizzards are we going to have this season? For most of the United States the answer is 0. For states in the Red River Valley the question becomes more complicated.
The Red River Valley is located in an area called blizzard alley. Blizzard alley has a similar concept to tornado alley. States in blizzard alley have a higher chance of receiving blizzards each year than the rest of the United States. States in the heart of blizzard alley include North Dakota, South Dakota and Minnesota. These states average between 1 and 2 blizzards each winter.
A blizzard according to the National Weather Service is defined as a storm which contains large amounts of snow or blowing snow, with winds that exceed 35 mph, visibilities less than a quarter of a mile and conditions lasting for 3 or more hours. The upper plains has the perfect terrain for these blizzard conditions as the states are generally flat and have few trees meaning it is easy for the wind to pick up snow and blow it across the plains reducing visibilities. Location is another factor as these states usually see strong low pressure systems move through in the winter associated with snow, strong winds and artic air.
In 2002 a study was done by Dr. Robert Schwartz and Dr. Thomas Schmidlin. They discovered the definite blizzard alley in the map above by compiling the number of blizzards from 1959 to 2000 over the United States. Their research found that the states in blizzard alley experienced 41 to 74 blizzards in the 41-year period. When comparing counties they found that 17 counties in North Dakota and 8 counties in South Dakota experienced over 60 blizzards in the time frame and Traill County alone experienced 74 blizzards in 41 years. Making Traill County, North Dakota the heart of blizzard alley.
When comparing winter seasons most seasons experienced an average of 2 blizzards. 1980-1981 season was the winter that experienced the least with only one blizzard recorded. On the opposite spectrum the winter before the 1997 Red River Valley flood was the season with the most snow and blizzards. 1996-1997 saw 27 blizzards that winter and each blizzard affected an average of 2.5 million people. This winter there is no need to worry about 27 blizzards happening but we could be seeing more than the average this winter. So don’t be surprised when you have to take out those shovels more than twice this year.
Written by: Kaela Lucke, an Atmospheric Science student at the University of North Dakota
Finding Blizzard Alley