“The Startling Truth About Tornado Risk Throughout the Year
Tornadoes pose a threat all year long in various parts of the United States, moving alongside warm, humid air and the jet stream as they travel north and south. Dr. Greg Forbes, a former expert on severe weather at The Weather Channel, has compiled data on average monthly tornado occurrences to create maps highlighting regions that are typically at risk of tornadoes each month.
Winter
Even during the winter months, tornadoes can still occur, as cold air yields to warm air surging northward to meet the jet stream, especially in the South. January and February see the highest frequency of tornadoes, with the February 2008 Super Tuesday outbreak marking a record of 86 tornadoes in a two-day span. These winter tornadoes are often fast-moving, difficult to spot due to being wrapped in rain or occurring at night.
March
In March, tornadoes can form in regions spanning from the central Great Plains to the southern Great Lakes, Ohio Valley, and Deep South. The month also holds the grim record of the deadliest tornado in U.S. history, the Tri-State Tornado of 1925, which claimed 695 lives. As March progresses, the South faces an increasing tornado threat leading into the spring season.
Spring
Tornado activity escalates rapidly in spring, with jet stream winds remaining strong and moisture returning northward. By April, surface dew points rise, providing fuel for severe thunderstorms as temperatures climb. May typically marks the peak of tornado activity nationally, fueled by warm air and disturbances from the Rockies.
Summer
During the summer, tornado activity intensifies in parts of the Midwest and Plains due to proximity to stronger jet stream winds. Tornadoes can occur nationwide during the warm months, often generated by popcorn thunderstorms in regions such as Florida and the Gulf Coast. Waterspouts may also come ashore during calm summer days.
Late Summer and Fall
In late summer and early fall, tornado activity may be influenced by tropical storms and hurricanes. These weather events can contribute to tornado formation in affected areas.”
In regions along the Gulf and Southeast coasts, such as Florida, the wet phase of the monsoon season intensifies from late July through August. This heightened activity leads to an increase in tornadoes and severe thunderstorms in Arizona, often resulting in dust storms. Northern Utah also experiences a slightly elevated period of tornado activity during this time, influenced by a convergence of conditions including the jet stream overhead and monsoonal moisture from the south. The local terrain can also impact the frequency of tornadoes.
During autumn, there is a secondary peak in tornado activity in the Gulf Coast states, which can sometimes extend northward to the Ohio Valley and southern Great Lakes. By November and December, the focus of tornado activity shifts back to the South, where warm air and abundant moisture provide favorable conditions. As the jet stream migrates southward for the winter months, anomalies in its path can create hazardous weather conditions in the Tennessee Valley and along the East Coast.
Late-season tropical cyclones along the Gulf Coast can further enhance tornado activity in the region. Although not commonly shown on maps, weak tornadoes occasionally form on the West Coast in November and persist into the winter months.
