Anyone who can call themselves a Hoosier knows that Indiana gets all forms of weather and severe storms are no exception. Tornadoes, large hail and high winds are all severe weather elements that the state experiences each year. These types of events can happen in any month of the year.
But a new study released from CoreLogic, a research and consulting company based out of California, suggests that the area of tornado risk is greater than just the traditional states in tornado alley. The states currently included in tornado alley include Texas, Oklahoma, Nebraska, South Dakota and Kansas. The report suggests that 18 additional states are part of this heightened area of activity. Indiana, Illinois, Iowa, Ohio, Missouri, Kentucky, Arkansas, Louisiana, Colorado, New Mexico, Minnesota, Wisconsin, Michigan, Tennessee, Mississippi, Alabama, Georgia and even Florida were all states identified as having a “very high” tornado risk. The map below demonstrates the CoreLogic findings. Anything in red or orange are considered "extreme" or "very high" areas of tornado activity. Those are the states listed above.
Here is a closer look at the state on Indiana and the report findings. The red dots suggest we are in an area of "extreme" tornado activity. The rest of the state is in the "very high" category.
The report was initiated after last year’s recording breaking number of tornadoes across the county. Some of the stronger tornadoes of the season happened outside of tornado alley in 2011.
But does this mean that the boundary for Tornado Alley should be redrawn? Or is the study merely pointing out what we’ve known for decades in the part of the county?
After examining the study, there were a few things that must be pointed out from a meteorological standpoint. The study only utilized data from the last 29 years. This is also the same time frame that Doppler radars became more present and more observers were in the field as the population grew, especially as the population expanded into more rural areas.
The study also put out a tornado frequency chart to show where tornadoes were recorded in the highest frequency. Central Indiana and Central Illinois were in one of those higher frequency areas on the map. But it didn’t specify the strength of said tornadoes. This part of the country will get a high frequency of weaker tornadoes like EF 0 and EF 1 tornadoes that pop up in squall lines. These rarely stay on the ground for long and don’t attribute to significant damage. EF 4 and EF 5 tornadoes are much rarer in the part of the county. See the map from NWS records of all EF 5 tornadoes on record (through 2011).
The study also included a tornado frequency chart and it highlighted where the “Tornado Alley” states fell in line to other states when looking at tornado frequency (see chart below). But again, this is considering all strengths of tornadoes.
What this study did do was reemphasize that we can and will see tornadic activity in the state of Indiana.
The Great Plains still has the best set up for tornado activity year after year and that is why it is considered Tornado Alley. But there are definitely areas of higher tornado frequency outside of this area, but they don’t happen as often as what is seen in the Great Plains. Events in the south and even the Ohio Valley are more like a feast or famine situation. You’ll have a great amount of storms for a few season and then nothing for a long period of time.
Note: The Corelogic study was geared toward insurance companies. The study suggested that this new data could lead to adjustments in insurance costs in the states outside of tornado alley. It is yet to be known if this study will impact homeowner insurance rates in Indiana.