With the exception of a few stragglers, we’re heading out of the summer severe weather season. The activity is usually on the incline starting late May (see below), peaking through June and July, then slowly tapering through August, and usually ending in September. Of course, this is based on 30 years worth of data. Not every year is the same.
Looking to past years, the number of severe thunderstorms warned is all over the place (see below). The highest number of severe thunderstorms warned in this time period was in 2010 at 523. The lowest number of severe storms warned since then was in 2017 at 153. This year, we had 181.
Corey King is a National Weather Service Meteorologist who says the dry and hot pattern that persisted over much of the Upper Plains likely led our prolonged peroids without storms.
“Once you get that hot dome of air that sits on top of us, Oftentimes it remains in place and this year I think one of the striking numbers for me was when you look at the number of 100 degree days in the Bismarck area especially…. we’ve now set the record where we’ve now had about 15 of them when [the record] was 14… back to 1936”
But putting the severe storm season into perspective using numbers only isn’t the best way to measure the season. The impacts are different for everyone. Ask anyone in Williston and NW North Dakota how this season impacted them and they’ll tell you that this was a rough one. A Presidential Disaster Declaration was declared because of flash flooding due to the June 10th storms.
If you looked at the graph of severe storm numbers (above) and wonder if there is a reason why we have been trending lower in the number of severe storms warmed… King adds, that there isn’t enough data to make assumptions.
“severe weather climatology, in general, is really kinda tough to nail down still simply because when you kinda look back at the historical record, severe weather overall… is a relatively young area I would say. When you look back to the number of reports we would get many years ago, they’re far fewer than what we get today.”
To put into perspective how young the science of meteorology is… we didn’t get the use of radar for the public until 1959. Around that same time, we got our first weather satellite.