Now that the “polar vortex” and extreme snowy and icy weather has finally subsided, it is time to gear up for tornado season.
In the U.S., tornado season is unpredictable, however, it tends to move northward from late winter to mid-summer. In Southern states, tornadoes usually wreak havoc from March to May. In the Southern Plains, from May to early June. On the Gulf Coast they come most often during the spring. And in the Northern Plains, Northern states and upper Midwest, peak season is in June or July.
But with unpredictable “Mother Nature”, tornadoes can happen at any time.
The two regions with higher incidences of tornadoes are Florida and Tornado Alley. Florida’s high tornado frequency is due to their almost daily thunderstorms during the season, as well as the many tropical storms and hurricanes that affect the Florida peninsula.
Tornado Alley was aptly named because of the extreme weather and tornado activity to a specific area. The alley includes a strip of land going north to south that covers the northern parts of Texas, Oklahoma, Kansas, Nebraska, Iowa, the eastern edge of Colorado, southwest tip of South Dakota and the southern edge of Minnesota. Tornadoes in this area typically occur in the late spring.
In the Gulf Coast region, another term given to this area in relation to its tornado activity is Dixie Alley. This area refers to West Tennessee, West Kentucky, North Mississippi and North Alabama. These states generally see a much later tornado season than those in Tornado Alley, occuring in the late fall from October through December.
It usually takes a thunderstorm for a tornado to form, but they can also appear during tropical storms and hurricanes. Most tornadoes will usually be at the right and ahead of the storm path as it comes ashore.
According to Roger Edwards of the Storm Prediction Center, “tornadoes are commonly said to be formed when warm, moist air meets cool, dry air, however that is a gross oversimplification.”
He notes that recent theories and results from the Vortex program suggest that tornado development is related to temperature differences across the edge of downdraft air, but mathematical modeling studies of tornado formation also indicate that it can happen without such temperature patterns.
“Very little temperature variation was observed near some of the most destructive tornadoes in history on May 3, 1999,” notes Edwards.
In other words – listen to warnings and watches and realize that these twisters are unpredictable – so at the first indication that a tornado is possible, all storm precautions should be taken.
Image via Wikimedia Commons