Marshal79344
Member
The more that I dive into the Cookeville, Tennessee EF4 Tornado of March 3rd, 2020, the more I'm astonished by its nature. In particular, the meteorology behind the Cookeville tornado is more interesting to me the more that I think about it. First of all, when the supercell produced the Nashville Tornado, it was in an environment with slightly more instability and slightly less lower-level shear and streamwise vorticity compared to when it produced the Cookeville tornado. In addition, the supercell had a clear inflow notch to the south with no form of obstruction when it produced the Nashville Tornado, compared to when it produced the Cookeville Tornado. Either, I would think that this means that the increase in shear either over-compensated for the decrease in instability, or that put both tornadoes on a level playing field, but the Cookeville tornado's narrow high-end damage swath and the law of the conservation of angular momentum explain its significantly higher intensity compared to the Nashville tornado's broader intense damage swath.
In addition, the tornado's sudden intensification is quite interesting. The tornado remained a relatively large but weak tornado for the first two miles before suddenly, as it entered the western part of the Echo Hills subdivision, a strong subvortex descended from the ground. It was only a block wide and gradually intensified until the instant the tornado reached Hensley Drive. When the tornado devastated the southern side of the homes along Hensley Drive at, in my opinion, mid-rage EF4 intensity, the wind field became much more complex and suddenly seemed to "thrash out" at points. This is illustrated below as the storm approached McBroom Chapel Road.
The grove of trees located behind the homes on the southern side of Hensley Drive also showed signs of violent tornado wind impact. They were completely denuded and partially debarked, as shown below. The wind field then seemed to shrink to a width of no more than three homes in a tightly packed subdivision for the rest of its life and weakened normally. The damage also seemed to peak in intensity at Hensley Drive, when the EF3+ wind field was at its most inconsistent and complex, which I think is interesting to note.
The grove of trees that was entirely denuded and partially debarked:
In addition, the tornado's sudden intensification is quite interesting. The tornado remained a relatively large but weak tornado for the first two miles before suddenly, as it entered the western part of the Echo Hills subdivision, a strong subvortex descended from the ground. It was only a block wide and gradually intensified until the instant the tornado reached Hensley Drive. When the tornado devastated the southern side of the homes along Hensley Drive at, in my opinion, mid-rage EF4 intensity, the wind field became much more complex and suddenly seemed to "thrash out" at points. This is illustrated below as the storm approached McBroom Chapel Road.
The grove of trees located behind the homes on the southern side of Hensley Drive also showed signs of violent tornado wind impact. They were completely denuded and partially debarked, as shown below. The wind field then seemed to shrink to a width of no more than three homes in a tightly packed subdivision for the rest of its life and weakened normally. The damage also seemed to peak in intensity at Hensley Drive, when the EF3+ wind field was at its most inconsistent and complex, which I think is interesting to note.
The grove of trees that was entirely denuded and partially debarked:
