Spring severe weather is upon us, and this year has proven to be especially wet and stormy for both Mississippi and Alabama. So far, Mississippi has seen 23 confirmed tornadoes in 2021, some rain-wrapped with up to 135 mph winds. The St. Patrick’s Day tornado outbreak that caused severe weather across the Gulf region on March 17, 2021, saw the development of supercells across central Alabama that eventually produced 25 total tornadoes in the state in a single day. Believe it or not, this day ranked No. 6 in single events in a day for the state (April 27, 2011 ranks No. 1 with 62 confirmed tornadoes in one day).
With all of the messaging about watches and warnings, one thing that often gets overlooked is the high rate of fatalities that occur at night. Yes, at night. Tornadoes can and do happen at night, and nocturnal tornadoes are more than twice as likely to kill people than daytime tornadoes. Between 1985-2005, research by Walker and Ashley shows that nighttime fatalities account for 66.7% of fatalities in Mississippi and 50% fatalities in Alabama (see Figure 1). This is higher than the national average of 42.5%.
Reasons for nighttime fatalities
Why do nighttime tornadoes cause so many fatalities? One obvious reason is that people are sleeping at night and caught unaware. They often turn their cell phones to silent and have no way to receive warnings.
Another challenge that meteorologists face is the fact that people are more likely to heed warnings if a tornado is spotted on the ground. People tend not to seek shelter until they “confirm the threat.” At night, there are fewer storm chasers, and even when a tornado is spotted, it is difficult to see in the dark. Therefore, there are no videos to encourage people to take shelter or provide the visual confirmation needed to encourage sheltering.
In addition, tornadoes can be a concern anytime of the year in the South. Figure 2 shows how the core winter months of December through February can produce nocturnal tornadoes, but how there is also a peak in November. March through June are like a “second season” for nighttime tornado occurrences. The public’s awareness of severe weather may not be as high during winter months, even in places that have experienced damages in the past.
What you can do
First, you should be aware of possible overnight severe weather before heading to bed. Then, have multiple ways to receive information on watches and warnings.
Buy a weather radio and be sure it has new batteries and is turned up loud enough where the warning alarm would wake you at night. Utilize your smart phone, most are capable of receiving wireless emergency alerts from your local National Weather Service office. Be sure your phone is charged and left “on” overnight, and a special tone will sound when a tornado warning is issued. This may save your life. You can also download an app that send alerts to your smart phone or tablet. The Weather Channel and Weather Underground both have apps that will send alerts.
In addition, check your local emergency management office for information specific to your area, most will have a way to sign up for alerts on their website. It is always a good idea to have a friend or relative that will call you in case of a weather emergency, just to check that you are aware and can prepare. Turn on your local TV and radio stations once you are awake so you can listen for changes in the pathway of the storm(s). Finally, identify your safe space prior to severe weather and know where to go. Keep a flashlight handy and be sure you can quickly get to a safe location.
The Mississippi-Alabama Sea Grant Consortium, in collaboration with the National Severe Storms Laboratory VORTEX-SE Outreach Program, is using this important message to raise awareness of nocturnal tornadoes with magnets that have a lenticular display. If you would like one for your refrigerator as a reminder, please contact me at tracie.sempier@usm.edu or (228) 818-8829 to receive one in the mail.
References
Ashley, Walker S. (2007). Spatial and Temporal Analysis of Tornado Fatalities in the United States: 1880-2005. Weather and Forecasting, 22, 1214-1228.
Ashley, Walker S., A. J. Krmenec, R. Schwantes (2008). Vulnerability Due to Nocturnal Tornadoes. Weather and Forecasting, 23, 795-807.
https://www.livescience.com/18707-winter-deadly-nighttime-tornadoes.html
https://weather.com/storms/tornado/news/nighttime-tornadoes-deadly-study