Wild weather as fall 2020 sees near-record snow, wide-ranging temps
2020 the fifth-snowiest October on record
The Mitchell area experienced below normal temperatures and above normal snowfall for the month of October, with snowfall amounts measured as the highest since 1995 and reaching the top five depths for the month.
According to the National Weather Service in Sioux Falls, Mitchell received 4.5 inches of snow during the month. That puts it at the fifth-highest amount of snowfall in October all-time. The heaviest snowfall in Mitchell for the month came in 1929, when 8 inches descended on the community. That was followed by 6.5 inches in 1905, 6 inches in 1995, 5 inches in 1898 and 4.5 inches in 2020.
The amounts continue to drop from there, with 3.2 inches in 1932, 3 inches in both 1936 and 1906, 2.9 inches in 1925 and 2.8 inches in 1951.
The 4.5 inches in 2020 is 3.1 inches above average for October in Mitchell.
“That was arctic air blasting through what had been warm air, and that produced the snowfall. When you freeze warm air, there’s a little more moisture available in it,” said Tim Masters, a technician with the National Weather Service in Sioux Falls, about the unusually high snowfall for the month.
The 4.5 inches Mitchell received lines up with some other communities across in the region, including 4.8 inches that fell on Sioux Falls, 4.2 inches that fell on Sioux City and 6.8 inches that came down in Huron. The October snowfall for Huron is its fourth-heaviest on record, while both the Sioux Falls and Sioux City amounts are their eighth-heaviest.
The year 1991, the year of the well-known Halloween blizzard, does not appear in the top 10 October snow totals for either Mitchell or Huron, though it tops the list for Sioux Falls and Sioux City, which recorded 10 inches and 9.8 inches in October that year, respectively.
Masters said NWS records show that the 1991 Halloween blizzard had heavier snowfall east of Mitchell.
“That snowstorm in 1991 did not really hit everybody. The (snowfall) records seem to be around Sioux Falls, and the farthest west it got was Menno,” Masters said. “It kind of hit more places farther east of there, and more into northwest Iowa and southwest Minnesota.”
He said the heaviest snowfall recorded on Halloween in Mitchell was 2 inches in 1929.
In addition to the snowfall, Mitchell experienced temperatures that were well below normal for this time of year.
The National Weather Service indicates Mitchell saw an average high temperature of 56.1 degrees, which is 5.8 degrees below normal for October. In Sioux Falls, the average high of 55.6 degrees was 4 degrees below normal, while Huron saw an average high of 54.1, which is 6.3 degrees below normal.
That trend continues with low temperatures. The average low of 32.8 in Mitchell in October was 4.6 degrees colder than usual. Sioux Falls saw average lows at 33 degrees, which is 3.1 degrees colder than normal, and Huron experienced an average low of 30.5, about 4.9 degrees below average.
Mitchell also saw a wide spread in high and low temperatures, with the high climbing as far as 88 degrees on Oct. 9 to as low as 7 degrees Oct. 27.
Masters said fluctuations between highs and lows that extreme are relatively uncommon, but conditions were right for it this year.
“The upper air flow is coming from way up north or way down south, which is giving us a wide range of temperatures,” Masters said.
Warmer temperatures are expected throughout the region this week. Mitchell is forecast to see highs in the 70s for the remainder of the week, but Masters said to expect temperatures to drop substantially after the weekend.
Those who have outdoor work left to do should plan to wrap it up in the coming week, he said.
“This week should be warm, and next week will be cold. Probably below normal,” Masters said. “We’ve been advising anyone that has outdoor activities to take care of them. Leaves, cleaning gutters, getting the garden put away, getting things out for the winter and put away from the summer. This weekend from Saturday into Sunday we will transition to colder weather and possibly wetter weather.”
Masters encouraged residents to prepare for the upcoming winter months now before severe weather hits. The National Weather Service provides winter preparedness advice on its website www.weather.gov/safety/winter and through its Twitter and Facebook feeds.