EF1 tornado, Clementsville to Harlan Xrds, Tennessee, December 9, 2023

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF1

Date

December 9, 2023

Touchdown

6:07 PM CST (00:07 UTC)

Lifted

6:11 PM CST (00:11 UTC)

On the ground

4 minutes

Path length

2.9 miles (4.6 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$50,000

Counties

Monroe and Clay counties

Touchdown point

36.617, -85.723

Lift-off point

36.631, -85.683

Record number

2312091807-02

20 damage points were recorded along this path by NWS LMK and NWS OHX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

• Shed demolished. Contact Shannon White 270.459.0895 According to Shannon, the wind came from the east, although the storm was traveling towards the northeast. The damage direction was facing west.
• 2 Trees fell on power line here; 800 some customers were without power. Contact JR Thacker Tri county Electric: 270-459-1457
• A few trees snapped along Barber Shop Road near the KY border
• Several chicken bars suffered roof and siding damage

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A major tornado outbreak impacted Middle Tennessee during the afternoon and evening hours of December 9, 2023. With a surface low pressure system situated over the Great Lakes area, a cold front was oriented north-to-south from the Great Lakes southward into the southeastern United States. Ahead of this cold front, southerly flow advected plenty of moisture into Middle Tennessee as the atmosphere destabilized. Meanwhile, a potent low-level jet resulted in an abundant amount of wind shear. This helped to set the stage for organized thunderstorms with a tornado threat. Thunderstorms began to cross the Tennessee River into the mid-state during the early afternoon hours. The first tornado of the day touched down in Indian Mound in Stewart County. That same supercell spawned another, more significant, tornado in Montgomery County that impacted Clarksville. This was the strongest tornado of the event, causing EF-3 damage before it continued its path into Kentucky. In total, six tornadoes were confirmed from this event, including another long-track EF-2 tornado that impacted Davidson, Sumner, and Trousdale counties which was warned with a Tornado Emergency. Unfortunately, seven people were killed during this event.

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.

A brief EF-1 tornado touched down just south of the Kentucky border in Clay County where it blew down a few trees on Barber Shop Road. The tornado intensified to an EF-1 as it moved northeast into Kentucky.

A brief EF-1 tornado touched down just south of the Kentucky border in Clay County where it blew down a few trees on Barber Shop Road (EF-0). The tornado intensified to EF-1 as it moved northeast into Kentucky and caused significant roof and siding damage to several chicken barns in Harlan Crossroads. A home also lost its porch and part of its roof on Red Hill-Beech Grove Road. A few more trees were blown down west of of Beech Grove-Boles Road before the tornado lifted.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

21 minutes of warning. NWS OHX issued a tornado warning for this county at 23:46 UTC, 21 minutes before the tornado touched down, in force until 00:15 UTC.

The county was under a tornado watch, issued at 21:20 UTC and running to 02:55 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:03 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Nashville radar (KOHX), 88 km away, was scanning. The volume nearest the touchdown began at 00:07 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2023 tornado in TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

11 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.