No one in the U.S. was killed by a tornado in May or June for only the second time on record

July 5, 2018 0 Comments

For the first time since 2005, and for only the second time since record keeping began in 1950, no one was killed by a tornado in the United States in May or June. May and June are the most active months of the year for tornadoes, and subsequently, are the most deadly.

On average, 71 people are killed in America every year by tornadoes, but so far in 2018 only three people have died. This is because of a number of reasons, with one of the primary ones being it’s been a quiet year for tornadoes. So far this year, there have been 456 confirmed tornadoes (still preliminary), and only five of those have been intense (rated EF-3 or higher). To put this in perspective, through the end of June 2017 there had already been 1,049 tornadoes nationwide. Heck, Oklahoma didn’t even see it’s first tornado until May this year! We’re also (thankfully) seeing a quiet year here in the Badger state, as only 6 tornadoes have touched down. Last year on June 14th, 10 tornadoes alone touched down in Wisconsin! Our annual average is 23.

Laramie, WY tornado from June 6th Credit: Aaron Voos

Another big reason is that radar technology has improved. Because of this, watches and warnings are issued in a more timely manner, and many of these alerts are sent directly to your cell phone. (If you currently don’t get watches and warnings sent to your phone, download the free StormTrack9 weather app!)

Richfield, WI EF-0 Tornado May 9th Credit: NWS

So why are we having such a quiet year? Well, there are four main ingredients generally needed to produce tornadoes: instability, moisture, lift, and wind shear (change in direction and speed of the wind with height). As we all experienced, there were many rounds of cold, dry air that came down from Canada during April and May, which kept the northward extent of any moisture limited to the southern United States. The jet stream also wasn’t in a favorable position to produce storms in Tornado Alley, and once it was, the storms produced more straight line wind damage instead of tornadoes. Sprawling high pressure across the region during the month of May also limited storm development.

The dying La Niña also likely played a role suppressing storms by keeping “winter” around for so long this year, but an El Niño Watch is currently in place with a 50% chance of one developing by fall, and a 65% chance by winter. This could increase the number of storms as we head into the second half of the year.

About the Author:

Leave a Reply