While spring has the most notorious reputation for severe thunderstorms and destructive tornadoes, a twister can spin up somewhere in the U.S. during any month. That includes the typically wintry month of February when you'd likely be expecting a snowstorm rather than a severe storm.
Applying a statistical analysis to the locations and frequencies of confirmed tornadoes in the U.S. since 1950, FOX Weather senior weather data specialist Shane Brown compiled the map below illustrating the areas most susceptible to twisters in February.
During the winter months, when much of the nation is shivering in cold temperatures, there's still a notable probability of tornadoes in parts of the South. That's because the jet stream sets up camp in the southern U.S. for the winter, causing a sharp temperature contrast between cold air to the north – originating from Canada – and warm air to the south pulled in from the Gulf of Mexico.
The jet stream is also at its strongest in the winter because of that clash of air masses. A stronger jet stream can be fuel for severe weather, adding the spin and energy needed in the atmosphere for thunderstorms to grow and intensify, possibly leading to the formation of tornadoes. Wintertime severe storms are often found where there’s a southward dip in the jet stream – called a trough – or a cold front moving through a region.
In February, the general tornado risk area extends from southeastern Missouri, southern Illinois and the western half of Kentucky southward to the Gulf Coast and parts of the Southeast. That includes cities such as Houston, New Orleans, Atlanta, Memphis in Tennessee and Tampa in Florida.
An average of 44 tornadoes occur in the U.S. each February, which ranks as the second-least-active month for twisters. Only December, with an average of 32 tornadoes, ranks lower than February.
As a whole, the U.S. averages 1,333 tornadoes annually, of which more than half tend to occur between April and June.
The areas most vulnerable to tornadoes change throughout the year as the jet stream migrates north and south. This story discusses where tornadoes are most likely to occur in each month.
2008 ‘Super Tuesday’ outbreak was largest February tornado outbreak
Between Feb. 5-6, 2008, 87 tornadoes were confirmed across nine states in the South, which was the most tornadoes to ever occur in a single February severe weather event on record. According to the National Weather Service, 57 people were killed across Arkansas, Tennessee, Kentucky and Alabama.
The event was dubbed the "Super Tuesday" outbreak because the two-day event began on Super Tuesday as 24 states held primary elections and caucuses to select the presidential candidates for the presidential election in November of that year.