Comparing the March 1966 and April 1997 Blizzard

North Dakota has many memorable blizzards in its history, but one other particularly severe rendition paralyzed much of the state in early April 1997.  Many hardy North Dakotans call the April ’97 storm the worst that they can recall.  Others that lived through the March ’66 blizzard say that one was far worse than the April ’97 storm, and any other blast of heavy snow and wind they have experienced, for that matter.  Can we definitively say which blizzard should take its place as king of all modern-day North Dakota blizzards?

A blizzard is officially defined as a severe winter storm with sustained winds or frequent gusts of 35 mph or greater and considerable falling and/or blowing snow that reduces visibility to less than one-quarter mile for at least three hours.  Some North Dakota blizzards are “ground blizzards” which merely blow around snow already on the ground, with little if any accumulation. The March ’66 and April ’97 blizzards, on the other hand, also had very heavy falling snow to go with their high winds, which made them particularly harsh. We can look toward snow totals as one way to compare the two. The maximum reported snowfall in North Dakota with the March ’66 storm was 32 inches at both Grafton and southeast of Linton at Hague.  The highest snowfall total with the April ’97 blizzard was 33 inches, recorded 5 miles south-southeast of Butte in central North Dakota.   In that regard, the April ’97 storm narrowly edged out the March ’66 event.  Of course, it’s not just heavy snow, but also wind that makes blizzards like these memorable.  The Bismarck Airport has a reliable record of peak wind gusts during both blizzards and was near the core of strongest winds with both systems, so it provides a good comparison. It turns out that the peak wind gust at Bismarck for both the March ’66 and April ’97 blizzards were not too dissimilar, though the 1966 event had a bit higher maximum gust of 64 mph compared to the 1997 blizzard, which had a peak gust of 60 mph.

Another way to compare these two historic events is to consider the number of hours during which blizzard conditions with very low visibility occurred. During the 1966 storm, Bismarck experienced 43 consecutive hours of blizzard conditions.  In comparison, the city only had about 14 hours of true blizzard conditions during the 1997 event, even though the storm itself lasted longer.  In that regard, it may appear that the March ’66 blizzard was indeed far worse.  In fact, if we look only at Bismarck, we may be able to say pretty conclusively that the March ’66 blizzard was quite a bit worse than the April ’97 one:

Of course, we cannot consider only Bismarck.  Locations further east and north like Jamestown and Grand Forks experienced closer to 24 hours of blizzard conditions in the April ’97 event; still less than in March ’66, but certainly crippling.  We already know the highest snowfall amount anywhere in the state was slightly greater with the 1997 storm.  One other stark difference between the two events was that the 1966 event started out as mainly snow, while the 1997 storm began with freezing rain in parts of the state, resulting in an ice storm in some areas before the blizzard.  Impacts were severe with both blizzards, but came in different manners.  So, if you ask us if the March 1966 blizzard was worse than the one in April 1997, we’ll have to answer “yes”, and “no”.  However, we can confidently say that both were extreme events,  and that more blizzards like them can and probably will visit North Dakota again some Spring when the changing seasons battle one another.