April 2021's Unusual Tornado Pace in Rare Company

 Chris Dolce

Published: April 27, 2021

April 2021 is on pace to be one of the least tornadic Aprils in three decades, marking a complete reversal from an extremely active March and April of last year.

The preliminary count of tornado reports across the U.S. this month was 51 through April 25, according to statistics compiled by NOAA's Storm Prediction Center (SPC). That's roughly one-quarter of the month's 20-year average of 194 tornadoes.

Each red icon represents a tornado report for the period April 1-26, 2021.

Although this April's final tornado total won't be known until well after the month has ended, it's possible we could wind up with fewer than 100 tornadoes for just the fourth time in April since 1990. The last time that happened was in April 2013, which had 86 tornadoes. April 1992 (53) and 1993 (85) are the only other years in the last three decades to have fewer than 100 twisters.

This is quite a reversal of fortune from last month, which had a preliminary 191 tornado reports, according to SPC. We don't know what the final official tornado count from March will be, but it's safe to say it will be far above the month's 20-year average of 83 twisters.

April 2021 has also been the polar opposite of last April, which had a preliminary count of 271 tornadoes. That made it the second most tornadic April on record, but still well behind the record set in April 2011.

The reason for the relative dearth of tornadoes so far this month is simple.

Surges of cooler than average temperatures have dominated parts of the central and southern U.S. for a better part of the month, especially the past two weeks. That has limited the availability of significant Gulf of Mexico moisture toaPRI the east of the Rockies, which is one of the key ingredients for the formation of severe thunderstorms.

Of course, this has no bearing on what will happen through the rest of spring.

May has historically been the most active tornado month in the U.S. That's because the geographical area most favorable for the development of severe thunderstorms grows larger in size as warmer temperatures become more expansive.

(MORE: Most Dangerous Time of Year For Tornadoes)

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.