Arkansas has significant tornado activity and is highly prone to severe weather events. The state’s geographical position places it in the path of weather systems that commonly produce powerful, rotating storms.
Frequency and Severity of Tornado Activity
Arkansas experiences an average of 37 tornadoes annually, based on a thirty-year period from 1991 to 2020. This number can vary widely from year to year, with some years seeing fewer than 20 and others, like 1999, recording over 100. The state is situated within “Dixie Alley,” a region known for a high frequency of intense tornadoes, which often occur later in the season or at night.
The majority of tornadoes are classified as weak, typically rated EF0 or EF1 on the Enhanced Fujita (EF) Scale. However, the state has experienced destructive storms, including those rated EF3, EF4, and an F5 in 1929. Since 2000, tornadoes rated EF3 or higher account for a small percentage of total occurrences, but they are responsible for a disproportionately large share of tornado-related fatalities. Strong and violent tornadoes are few, yet historically they have caused approximately 80% of tornado-related deaths.
Seasonal Peaks and Timing
Tornado activity in Arkansas follows a distinct pattern, characterized by a primary and a secondary season. The main season runs from March through May, when the clash between warm, moist Gulf air and cooler, drier northern air is most common. Nearly half of all observed tornadoes have historically occurred during this three-month span.
A secondary, less intense tornado season often develops in the late fall and early winter, typically spanning November and December. Regarding the time of day, tornadoes are most likely to occur during the late afternoon and early evening, generally between 2:00 PM and 10:00 PM. The risk of nighttime tornadoes, particularly in the cooler months, is a considerable threat, as they are more difficult to spot and warnings can be less effective while people are asleep.
Geographic Distribution of Risk
Tornado risk is not uniform across the state, with terrain playing a measurable role in vulnerability. The highest concentration of activity clusters along a corridor running from Central Arkansas northeastward toward Jonesboro. This region, which includes parts of the Arkansas Delta, is more susceptible to long-track, powerful storms that sustain themselves over flat ground.
The rugged terrain of the Ozark and Ouachita Mountains in the western and northern parts of the state can sometimes interfere with the formation of severe storms. While these mountainous regions experience tornadoes, the overall frequency is statistically lower compared to the eastern lowlands. The eastern lowlands, where the atmospheric conditions and flat topography are more conducive to large, long-lived tornadic systems, see a high frequency of these powerful storms.
Understanding Warnings and Preparedness
Public safety relies heavily on understanding the difference between a Tornado Watch and a Tornado Warning. A Tornado Watch means that conditions are favorable for tornadoes to develop in the designated area. This is the time to review your emergency plan, monitor the weather, and ensure your emergency kit is accessible.
A Tornado Warning means a tornado has been sighted visually or indicated by Doppler radar, posing an imminent threat to life and property. When a warning is issued, immediate action is required to move to a designated safe place. The safest shelter is an underground area like a storm cellar or basement. If those are unavailable, the best alternative is an interior room or closet on the lowest floor, away from windows.
Every household should maintain an emergency kit containing essential items, such as:
- A battery-powered NOAA weather radio.
- Non-perishable food.
- Water.
- Flashlights.
- A first-aid kit.
Mobile homes and vehicles offer virtually no protection and must be evacuated for a more substantial shelter when a warning is issued. The state’s warning infrastructure provides precious minutes for residents to take cover.