March 17-18, 2021 tornado outbreak

A multi-day tornado event swept across parts of the mid-South and Southeast, focused on Mississippi and Alabama. Among at least 46 tornadoes in total over the two days, some strong twisters occurred and caused significant damage.

At least seven injuries have been reported, but fortunately it appears there have been no deaths.

March 17 was the first “high risk” — level five of five — from the Storm Prediction Center in March since 2012, and the first overall since May 2019. As we’ve detailed here before, high risks are almost a guarantee of a tornado outbreak.

These events can be fickle, and the South is known for storms congealing into blobyblobs, yet many storms stayed discrete or semi-discrete, quickly rotating then dropping tornadoes over a relatively large region. The second day of the outbreak may have underperformed in the Carolinas, with the risk dropping from moderate (4 of 5) to enhanced (3 of 5) and not even reaching that level.

On March 17, tornadoes were confirmed from southern Mississippi to south-central Alabama. It’s likely those two states will be remembered as ground zero of this outbreak.

A second round of storms developed late in the day to the west. New twister reports were logged from Louisiana, Arkansas, and Missouri. That batch of storm progressed over areas earlier hit and into parts of the Southeast into the night.

Over the two days, 121 tornado warnings were issued as were 18 tornado watches.

Several long tracked supercells developed over the Carolinas on March 18. Other circulations were noted in convective lines or line segments. As of late March 18, one tornado has been reported in Georgia. It’s certainly possible that more will be found as storm surveys happen.

This story is developing and will be updated periodically. Last updated, March 23, 10:05 a.m. CDT.