EF1 tornado in Madison County, Kentucky

A tornado developed on the backside of a squall line, first touching down just south of Runyon Grove. Near this location the tornado snapped several trees and caused major damage to a hay barn. The tornado continued northeast, where it caused damage to a chicken coop and dog run. The tornado continued into the Braemar subdivision where it caused damage to numerous trees and roof damage to several homes. The tornado lifted a travel trailer over a red sports car. This action resulted in the travel trailer being flipped on its side and rotated 90 degrees from its original orientation. The tornado continued northeast of the subdivision where it lifted shortly thereafter. No downstream damage was found.

During the morning hours of January 12th, an area of low pressure moved through the Ohio Valley downstream of an upper trough across the mid-Mississippi Valley. The initial wave of storms along a warm front moved across north central Kentucky and southern Indiana during the pre-dawn hours, bringing generally sub-severe hail with isolated quarter-sized hail reports. Storms along this boundary were not surface based, but were able to utilize 500-1000 J/kg MUCAPE via steep mid-level lapse rates to produce convection which was of sufficient depth and strength to produce hailstones. Wind shear was more than sufficient for sustaining convection throughout the event, with anywhere from 50-60 kt effective bulk shear across central Kentucky. The second wave of severe convection formed ahead of the surface cold front, moving from west to east across the region during the early and mid-morning hours as a broken quasi-linear convective system (QLCS). Modest destabilization occurred ahead of this second line of storms; however, the antecedent near-surface inversion was able to erode, contributing to the development of 200-500 J/kg of SBCAPE. As a result, severe impacts transitioned from predominantly elevated ones to surface-based threats. While scattered straight-line wind damage was initially the dominant severe impact, convection encountered a local maximum in 0-1 km storm-relative helicity as it crossed Interstate 65, with greater than 300 m2/s2 0-1 km SRH analyzed on SPC hourly mesoscale analysis. In addition, the segment of the QLCS which passed through the Bluegrass region had an orientation which was more perpendicular to the 0-3 km bulk shear vector, indicating a greater potential for embedded tornadoes. Accordingly, appendages and breaks within the QLCS produced several brief tornadoes across the area, with tornadoes being reported in Henry, Mercer, Boyle, and Madison Counties. The line continued to push into eastern Kentucky during the late morning hours, with the severe threat ending shortly thereafter.