A National Weather Service Meteorologist said instability over the Upper Cumberland caused the surprise tornado that ripped through parts Jackson, Putnam and Overton Counties Thursday.
Cory Mueller said thunderstorms developed along a cold front Thursday. As the storm moved into the Upper Cumberland, Mueller said wind sheer played a role in the storm intensifying.
“In order to get tornadoes you’ll want those winds to change direction with height,” Mueller said. “And as the storms went over the Cumberland Plateau we saw some of that and especially along the front we had more of that turning wind so there for we were able to get a tornado out of the storm.”
Mueller said February is usually a quiet month for tornadoes but they are not rare as Tennessee can have tornados in every month of the year.
Mueller said the difference between organized thunderstorms with tornadoes and spin-up storms is the profile of the wind sheers.
“If you have it turning in the low levels you can get the tornadoes along with a lot of instability,” Mueller said. “In order to not get tornadoes you generally want all of the wind sheer to be in the same direction and you will have less spin in the low levels.”
Mueller said the National Weather Service will be sending crews to the Upper Cumberland to review storm damage. Mueller said they will be looking at debris to determine if damage was caused by the tornado or high winds.
“They will be looking to see the pattern of the debris is facing,” Mueller said. “If it’s more scattered you are looking at tornados. If it’s more in one direction you will be looking at straight-line winds and we will probably have a little bit of both throughout the Cumberland Plateau.”
Mueller said often times moisture from the Gulf of Mexico meets cold air from the north causing a lot of spin-up storms to form in the Upper Cumberland.
