It’s been a quiet start to the severe weather season and today’s threat did not materialize for most of the area. Is this part of a long-term trend?

I received an interesting question from a viewer today. His impression was that we did not get as many thunderstorms in the Spring season as we used to. I have heard a similar sentiment from a few others. So is it really the case? Or is it largely “recency bias”, where our brains favor recent events over historic ones? Let’s look at some data.

NUMBER OF SEVERE THUNDERSTORM AND TORNADO WARNINGS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICES IN CLEVELAND AND PITTSBURGH THROUGH MAY 26

Data goes back to 1986.; As you can see there is a lot of year-to-year variability. Cleveland averages 47 warnings through May 26, Pittsburgh 42. This year is obviously WAY below average (Cleveland issued their first warning of the year TODAY). Notice that while Cleveland has generally issued fewer warnings than average in recent years, Pittsburgh had above average warnings from 2017-2020.

Of course these offices cover a much larger area than just our TV viewing area and unfortunately county-by-county data is hard to come by.

BUT WE CAN LOOK AT THE AMOUNT OF THUNDER REPORTED AT THE YOUNGSTOWN-WARREN AIRPORT

Note the complete lack of thunder from January-March this year. April had less than average and May has seen WAY less than average. Part of a recent trend? Let’s look at 2020 and 2019.

2020 DID have a lack of thunder in the Spring season but that was made up for by a pretty active June and July. October was unusually thundery.

2019? Quite thundery. Most months had more than average.

SO, CAN WE DRAW ANY CONCLUSIONS?

This is just a “quick and dirty” look at some recent data. But I do suspect, as is often the case with weather, there is a fair amount of recency bias going on. I often hear in the winter/early spring: is it WINDIER than it used to be? The answer to that one is no, it’s windy at that time of the year every year. We live in a windy place from November-April.

That said, nationally there are some long-term trends revolving around severe weather. The most frequent destructive tornadoes are occurring farther east…not as often in the Plains states and more often in the Deep South. The nation has (thankfully) not had an EF5 tornado in several years, an unusual (and fortunate) streak.

What’s going on there, as is often the case with weather, is likely some mix of climate change and random chance/luck.