Episode narrative: A strong storm system moved through the eastern half of the United States from December 9th-11th, 2023. The storm system was supported by a broad upper level trough which deepened and amplified over the central and eastern CONUS on December 9th. At the surface, a cold front over the Mississippi Valley on the morning of the 9th gradually moved eastward across Kentucky and Tennessee through the afternoon and evening hours. Ahead of the cold front, low level warm and humid air from the Gulf of Mexico was lifted northward into Middle Tennessee and South Central Kentucky, which when combined with approaching cold air in the mid-levels of the atmosphere, provided enough instability to develop showers and thunderstorms in the pre-frontal environment during the afternoon and evening hours on December 9th.

Although instability was an important ingredient for the development of thunderstorms, the amount of vertical wind shear in the atmosphere was the key factor that gave storms the potential to become strong and severe. While winds near the ground ranged from 10 to 15 mph out of the south and southeast, winds 4000-5000 feet off the ground were 45 to 55 mph out of the southwest. This combination of changing wind direction and increasing wind speed allowed for the development of supercell thunderstorms, which began to form across west and northwest Tennessee just after noon. Storms continued to increase in intensity during the early afternoon hours, with one particular supercell west of Clarksville, Tennessee becoming the primary storm of concern for our area. A tornado formed near the perimeter of Fort Campbell before moving northeast, producing up to EF-3 damage in northern Montgomery County, TN. The cell then crossed into Kentucky in southern Todd County, where it was on the ground for over 13 miles, producing up to EF-2 damage.

The tornado continued into the NWS Louisville County Warning Area near the community of Allensville on the Todd/Logan County line. In Logan County, the tornado remained on the ground for over 22 miles, producing up to EF-2 damage with maximum estimated winds of 115 mph. The tornado barely crossed into far northwestern Simpson County before lifting about 2 miles southeast of Auburn. However, rotation just off the ground within the mesocyclone remained strong, with funnel clouds being observed as the storm passed through extreme northwestern Simpson County and into southwestern Warren County. Ultimately, a second tornado from the same storm touched down on the south side of Bowling Green, producing up to EF-1 damage with maximum estimated winds of 90 mph over a path of around two and a quarter miles.

Later in the evening, a third tornado also touched down in far northern Clay county Tennessee and then moved across the state line into Monroe county Kentucky. This brief EF-1 tornado did most of its damage near the Harlan Crossroads community before lifting.

Tornado event in LOGAN County, KENTUCKY
Start: 09-DEC-23 14:15:00
End: 09-DEC-23 14:48:00
Direct deaths: 0
Event narrative: The National Weather Service in Louisville conducted a storm damage assessment survey in Logan County, Kentucky from the storms on Saturday, December 9th. The survey was conducted in very cold conditions with temperatures in the mid to upper 30s with storm damage over 22 miles. 

This storm damage survey is only for the Logan County and Simpson County, Kentucky, portion of a long-track EF3 tornado that touched down on Fort Campbell in Montgomery County, Tennessee. The tornado tracked east northeast across the southern part of Todd County, Kentucky. The tornado continued eastward from Todd County, Kentucky, dropping debris from Allensville into farmers fields between the county line and Gossett Hines Road. The tornado sucked up leftover corn and beans from the fields, throwing them in all directions and covering portions of the roadway. It also knocked some power lines down in this area with wind speeds estimated at 95 mph (EF1) and a path width of 125 yards.

The tornado continued east northeastward, topping some trees near the intersection of Paul Young Road as well as doing significant structural roof damage to a barn. Wind speeds were estimated at 90 mph (EF1), with a path width of 100 yards. 

The tornado increased in width and intensity as it approached Lickskillet. A series of small vortices inside the tornado increased the width to 250 yards, with wind speeds estimated at 115 mph (EF2) in a small area off of Lickskillet Road. A well-built two-story house sustained extensive roof damage, had its foundation shifted, windows blown out, 3 vehicles thrown and severely damaged, and 2 barns destroyed with impalement of barn boards. Debris was thrown several hundred yards from the north to  the east southeasterly direction. NWS drone footage clearly showed a large forested area had trees snapped, uprooted, twisted and facing numerous directions. The drone footage also showed debris deposited up to 500 yards to the east northeast. 

Several barns and outbuildings were destroyed along Lickskillet Road, with barn metal sheeting wrapped around trees and insulation on the front and back sides of homes. The survey team once again observed leftover corn and beans from harvested crops thrown all over the place. Wind speeds in this area ranged from 95 to 105 mph (EF1) with a damage width of 250 yards. 

Witness testimony and video clearly showed several small vortices mainly rain wrapped in this area. Numerous people heard the strong wind and roar and felt a severe pressure drop in their eardrums. 

The tornado next hit a couple of homes on Watermelon Road (Hwy 1041). Significant roof damage occurred, including major loss of shingles, loss of gutters and large sections of the roof ripped off and mangled. There were several uprooted trees, and 2 outbuildings were destroyed. Some damage was thrown 400 yards to the east northeast. Wind speeds in this area ranged from 95 to 105 mph (EF1) with a width of 250 yards.

The next concentrated damage area was near the intersection of Johnson Young Road (Highway 739) and McIntosh Road. Several greenhouses had their roofing material ripped apart and bent, and two outbuildings and one barn were destroyed. Several witnesses had video of the tornado, which showed several small vortices. This was extremely helpful to determine why some areas had almost no damage, while other areas had substantial damage. Dozens of large trees were uprooted and snapped on the west side of McIntosh Road behind the greenhouses. Wind speeds in this area were between 100 and 105 mph (EF1) with a width of 250 yards.

The tornado significantly damaged roofing structures of two homes on Orndorff Mill Road (Highway 96). One middle section of the home on the west side of Hwy 96 was completely destroyed, and the home on the east side of Hwy 96 had most of its roof ripped off. There were some structural flaws to these homes and pine trees next to the home were not significantly affected. Thus, wind speeds were kept at 95 mph (EF1). Two barns were destroyed at this location as well. 

Along Nashville Road (Highway 431), there was some metal uplift of some barns and one outbuilding, while no foundation support was destroyed. Wind speeds were between 80 and 85 mph (EF0) with a width of 175 yards.

Along Franklin Road (Highway 100), there were several power poles snapped or knocked down, and some shingle, gutter, and soffit damage to one home. Wind speeds were 90 mph (EF1) with a width of 175 yards.

Along Dennis Corinth Road (Highway 2369), there was a partial uplift of an old barn. The debris from the barn was thrown to the north and east directions. The eastern debris struck a single- family residence, doing roof, gutter, and broken glass damage. Wind speeds were between 80 and 85 mph (EF0) with a width of 100 yards.

The last observed damage from the December 10th survey was roof damage to a barn on Carter Road with debris thrown into a farmer's field, stopping before Montgomery Road. Wind speeds were 85 mph (EF0) with a width of 60 yards. 

Upon further investigation by emergency personnel on December 18th, the tornado was found to have crossed Montgomery Road across mostly rural locations before more damage was observed at Matlock Road and Pamela Lane.  Roof damage to barns and outbuildings were found to be at EF0 strength at 80 mph.  The tornado then continued across Friendship Road and did damage along Harris Road where a barn under construction was leveled.  Winds in excess of 90 mph were determined to occur here at EF1 strength.

The tornado continued across Logan Middleton Road where EF0 damage occurred to a home and barns just to the east of the highway.  At this point, the tornado crossed just into Simpson county along Clifford Peart and J Wilson Road where additional barn damage occurred.  No additional damage was observed from the tornado beyond  Clifford Peart Road. In total, the damage track was extended an additional 4.59 miles for a total of 22.82 miles in the NWS Louisville warning area, and a total of 47.75 miles from the origination point of Montgomery County TN.