All Weather News

Major Severe Threat From Arkansas to Alabama

17 Mar 2021, 6:30 am

A large portion of the Mississippi River Valley is under a risk of severe weather today (Wednesday).  A high risk has been added by the Storm Prediction Center, the highest threat level on a scale of 1 to 5.

Tornado Watches

Tune in to WeatherNation for the latest tornado watches. We have already confirmed numerous tornadoes across the deep south today and through tonight this severe threat will remain.  Several large, intense tornadoes will be likely in those areas with widespread damaging wind gusts up to 80 mph likely and large hail up to 1.5″ in diameter possible.

Severe Outlook

An extensive area has the potential to see severe thunderstorms through tonight. The risk area extends from central Missouri southward to the Gulf of Mexico from Mississippi to the Florida Panhandle. Moderate and high risks (levels 4 and 5 on a scale of 1 to 5) include most of the Tennessee and Lower Mississippi River valleys.

Tornado Potential

In the high risk area, long lived supercells are possible with the potential for significant tornadoes. Impressive wind shear (wind direction changing with height) is forecast to be present, sustaining severe thunderstorms and aiding in tornado development.

The Storm Prediction Center states “a significant tornado outbreak, with long-track, intense tornadoes is expected to begin this afternoon across parts of Louisiana and Arkansas, and then spread eastward and peak this evening into tonight across Mississippi and Alabama.”

Make sure you have multiple ways to get weather warnings tonight since more than one round of severe thunderstorms is expected. Everyone in your family should also know where to go in case a tornado warning is issued.

With the atmospheric ingredients in place today, any storm that forms will quickly be able to strengthen and acquire rotation. The Significant Tornado Potential is issued when the atmosphere can support long track, intense tornadoes of EF-2 strength (110+ mph) or higher.

Wind and Hail Threat

There is also a significant threat for damaging winds and large hail. As supercells form tornadoes through tonight (Wednesday), hail sizes greater than 2″ in diameter are likely. A squall line will form along the cold front this evening, increasing the potential for damaging wind gusts.


Severe thunderstorms are already on-going, coverage and intensity expected to continue tonight. A robust jet stream, increasing instability, and strong wind shear are all present to create a severe weather outbreak.

Discrete supercells ahead of the cold front pose the greatest threat for long lived, intense tornadoes. These are most likely in east Mississippi and west Alabama through the evening horus.

Rainfall and Flooding

The forecast not only includes severe thunderstorm chances, but also soaking rainfall.  Flooding is a concern with repeated rainfall occurring on over saturated soils.

If you are in the risk areas today, especially the moderate and high risks, have a severe weather plan in place. Check back with WeatherNation on-air and online throughout the the day for the latest alerts and forecast updates.

About the author
Alana Cameron was born and raised in Canada in the city of Mississauga, just outside of Toronto. Alana is the oldest of 4 siblings, all close in age, and grew up playing outside with them in all types of weather. After graduating high school, Alana moved to study at the University of British Columbia in Kelowna for a year before transferring to Dalhousie University in Halifax, Nova Scotia where sh... Load Moree completed a Bachelor of Science in Physics and Atmospheric Science. Upon completion, Alana moved back to Toronto where she completed a post-grad degree in Meteorology at York University. After her post-grad, she went on to complete another post-grad in Broadcast Journalism - TV News at Fanshawe College in London, Ontario. During her final year of studies she had the privilege of interning with the best in the business in Canada at The Weather Network. Once she finished her internship, she got the call from small-town Denison, Texas where she accepted a job as an on-air meteorologist at KTEN-TV, right in tornado alley, covering severe weather from Sherman/Denison (North Texas) to Ada (Southern Oklahoma). After the most active tornado season Oklahoma had seen in May 2019 (105 tornadoes!) Alana is excited to join WeatherNation to cover weather all across the nation. If you're interested in following her on social media she can be found @alanacameronwx!