Are November tornadoes rare?
Are November tornadoes rare? Was the November 17th Outbreak abnormal? Understandably, I have seen these questions asked via social media hundreds of times over the last several days. With the recent outbreak of tornadoes on the 17th in Illinois and Indiana that claimed 8 lives many people are confused as to how this can occur doing what most would think are the winter months. The month of November is notorious for surprising many as an active tornado month. In fact October and November have been coined the 2nd tornado season with the first being April, May & June. With that being said, the majority of tornadoes for the month of November historical have been further South where moisture and heat are typically more abundant for tornado genesis. The most recent tornado event on November 17th was abnormal in a few ways. First, as I said most of these events occur further South with Texas, Alabama and Mississippi totaling the most tornadoes in November since 1951. Second, this event had two violent tornadoes (a preliminary rating of EF4 has been given to the tornado that hit New Minden, Ill. 170-190 mph) (a preliminary eEF4 tornado hit Washington, Ill. 166-200 mph) and this certainly is abnormal for November. Most tornadoes in November are of the EF-0 to EF-2 strength. Certainly November tornadoes are not out of the ordinary. The tornado outbreak on November 17th however was unusually strong and further North than is typical of these events. A major drop off in tornado activity does historically occur in December, but even December is not completely immune to tornadoes. This is something to keep in mind if you live in the South or the Midwest as inevitably we will see another round of severe weather in Novembers to come.
• On average, only about 52 tornadoes are reported across the country during the entire month of November, according to data from the Storm Prediction Center.
• While most of the big tornado outbreaks tend to happen in the spring months of April and May, autumn also has its share of storms, according to Weather Channel meteorologist and tornado expert Greg Forbes. He said the second half of October and November can be ripe for severe storms and tornadoes.
• Forbes says that this time of year "is the counterpart to spring, when strong fronts and upper air systems march across the United States. "When enough warm, moist air accompanies these weather systems, the unstable conditions yield severe thunderstorms and sometimes tornadoes," Forbes said.
• The worst November tornado event in U.S. history was in 2002. On Nov. 10-11 of that year, a major outbreak of severe weather and tornadoes occurred across the Tennessee and Ohio Valley regions, producing damage in 13 states. A total of 75 tornadoes touched down on Nov. 10, killing at least 36 people.