NASHVILLE, Tenn. – You’ve likely heard about the severe storms that injured hundreds and killed nearly two dozen people in the Nashville area Monday night. We typically don’t see such dangerous tornadoes form this time of year, but they still happen on occasion. In fact, just last year on this same date, an EF-4 tornado killed 23 people in Lee County, Alabama.
A low pressure system was centered over the Indiana-Ohio border Monday night, with a cold front extending back to the southwest through Kentucky and Arkansas. A warm front was snaking down through Kentucky and Tennessee, providing the spark for severe storms. This was a particularly dangerous set up because all of this activity was happening at night when it’s more difficult to see if a tornado has formed.
The line of storms that produced the deadly tornado for the Nashville area moved through after midnight CST. The radar and velocity signatures at the time were quite impressive, allowing local broadcasters to alert locals to get in their safe places.
One way we can track where tornadoes will form is by analyzing a radar product known as “rotation tracks.” They let us know if the wind is rotating in the atmosphere within a thunderstorm. Using this product, we can see that a tornado (or funnel cloud) moved from west of the Nashville metro to areas east like Mount Juliet.
The National Weather Service office in Nashville has been conducting storm surveys throughout the day, finding up to EF-3 damage from up to 165 mph winds in places like Donelson and Mount Juliet. We are still waiting for the final storm survey report.