On the evening of Friday, December 10, 2021, a potent storm system moving across the central United States resulted in significant long-track tornadoes. A violent EF-4 tornado began in far northwest Tennessee, and moved across western Kentucky, resulting in dozens of lost lives and a swath of destruction. The tornado was on the ground for 128 miles within the NWS Paducah forecast area, and the total path length was about 165 miles from Obion County, TN to Breckinridge County, KY. Another long-track EF-3 tornado started in Dyer County, TN, and traveled about 125 miles through northwest Tennessee and into Christian and Todd Counties in western Kentucky. A strong upper-level trough over the western Plains induced a deepening surface low that tracked northeast across the Iowa/Illinois border. A very strong and deep southwest wind flow brought moist and unstable air into the Tennessee and lower Ohio Valleys. Record high temperatures were recorded, including a high of 73 at Paducah. The combination of very strong winds aloft, unseasonably warm conditions, and a strong low pressure system were ideal for this tornado outbreak.

Tornado in HICKMAN, KENTUCKY
From 10-DEC-21 21:06:00 to 10-DEC-21 21:16:00 (CST-6)
Location: CROLEY
Tornado F-scale: EF3
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell). This tornado crossed from Fulton County into Hickman County about 7 miles northwest of Fulton, close to the community of Croley. The tornado was exceptionally wide as it entered Hickman County, becoming about 1.5 miles wide. The tornado track in Hickman County was over rural farmland, bypassing small communities. The tornado achieved a rating of EF-3 over far eastern Hickman County, along Highway 58 near the Graves County line. This is where numerous wooden towers carrying electrical transmission lines collapsed (DI 24, DOD 6). This damage site is where the tornado was assigned the highest estimated wind speed in the county, about 140 mph. On Highway 307, there were four collapsed metal truss towers for carrying electrical transmission lines (DI 24, DOD 6). There were several injuries but no fatalities in the county. About a dozen homes were destroyed countywide. A mobile home was destroyed (DI 3, DOD 9). Most walls of one destroyed house collapsed, except small interior rooms (DI 2, DOD 8). The damage rating of this house was lowered due to toe nail construction. A total of 41 homes were damaged in Hickman County, and 12 were destroyed or uninhabitable. Hundreds of trees were snapped or uprooted. The average path width was about 1.25 miles (2250 yards). The tornado exited Hickman County into Graves County in a rural area about one-half mile north of where Highway 58 crosses the county line.

Tornado in MUHLENBERG, KENTUCKY
From 10-DEC-21 20:32:00 to 10-DEC-21 20:37:00 (CST-6)
Location: HILLSIDE
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This relatively weak and short-lived tornado occurred prior to the much larger and more powerful EF-4 tornado in northern parts of the county. The known damage path began about four miles north-northwest of Greenville along the Western Kentucky Parkway, starting at the Wendell Ford Regional Training Center grounds. Numerous trees and large branches were broken near the parkway. The tornado continued as far as the southwest city limit of Central City. Near the southwest city limit, a metal commercial structure suffered extensive roof loss and some damage to walls. Nearby, a house roof was damaged and windows were blown out. A nearby church received minor structural damage. A road sign along the Western Kentucky Parkway was blown about a tenth of a mile. Estimated peak wind speeds were near 95 mph.

Tornado in MUHLENBERG, KENTUCKY
From 10-DEC-21 22:55:00 to 10-DEC-21 23:10:00 (CST-6)
Location: EARLES
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell). This tornado crossed from Hopkins County into Muhlenberg County at the Pond River, about 8 miles southwest of Bremen.  The primary impact to Muhlenberg County was in and around the community of Bremen, where the tornado achieved a rating of EF-4. The Bremen area was the site of most of the 11 fatalities in Muhlenberg County. A total of 165 structures were damaged or destroyed, of which 84 were completely destroyed or uninhabitable. The remainder were damaged at least moderately. The majority of these structures were along and just south of Highway 175 from 5 miles southwest of Bremen to the community of Bremen. Several demolished houses in this area warranted a rating of EF-4. The destruction of one house warranted a wind speed estimate of 190 mph, the highest in the county and the entire track. One brick home on Highway 175 collapsed, and another was swept off the foundation (DI 2, DOD 9). A car in the garage was thrown across the road. A couple of poorly anchored houses were swept clean off the foundation within a few miles west of Bremen (DI 2, DOD 9-10). On the north side of Bremen, a two-story home was completely destroyed. The  foundation was not swept clean, but all walls were gone. Much of the remainder of the path through Muhlenberg County was unpopulated woods and fields. There was a cluster of damaged or destroyed structures near the community of Moorman, near where the tornado crossed U.S. Highway 431. In this area, a couple houses were heavily damaged, but most walls remained standing (DI 2, DOD 6). A number of vehicles were thrown and destroyed countywide, including some farm equipment. Nearly total tree destruction was observed in the path. The average path width was a mile. The tornado exited Muhlenberg County into Ohio County on the Green River about 2.5 miles east of Moorman. See Storm Data, Kentucky, Central for information on the remainder of this tornado path.

Tornado in FULTON, KENTUCKY
From 10-DEC-21 20:56:00 to 10-DEC-21 21:06:00 (CST-6)
Location: STATE LINE
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell). This tornado crossed from Obion County, Tennessee into Fulton County, Kentucky about 6 miles southeast of Hickman, close to the communities of State Line, KY and Woodland Mills, TN. The tornado rapidly widened, becoming over a mile wide across northeast Fulton County. The primary impact to Fulton County was on the community of Cayce, where the tornado achieved a rating of EF-4. This community was the site of the only fatality in Fulton County. A 57-year-old male occupant of a mobile home was killed. On the southwest edge of Cayce, a house was demolished (DI 2, DOD 9). This demolished house was assigned an estimated wind speed of 170 mph, the highest in the county. A small retail building in the center of town was demolished (DI 8, DOD 8). A total of 61 structures were affected in Fulton County, with 21 of those totally destroyed or uninhabitable. A number of vehicles were thrown and destroyed, including some farm equipment. Nearly total tree destruction was observed in the Cayce area. The average path width was a mile. The tornado exited Fulton County into Hickman County in a rural area about 7 miles northwest of Fulton.

Tornado in TODD, KENTUCKY
From 11-DEC-21 00:32:00 to 11-DEC-21 00:36:00 (CST-6)
Location: FAIRVIEW
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This long-track EF-3 tornado began in western Tennessee near Dyersburg (see Storm Data, Tennessee, Western). It crossed into Todd County from Christian County near the city of Pembroke. The tornado was near the end of its life in Todd County, where it only received a rating of EF-1. In Todd County, dozens of trees were snapped or uprooted. Roofs were blown off several barns. At least one house and several other farm outbuildings sustained minor to moderate roof damage. The windows were blown out of a few structures. The tornado lifted about four miles west of Elkton. This tornado was on the ground for approximately 125 miles across western Tennessee and western Kentucky. The tornado transitioned to a damaging straight-line wind event in the Elkton area.

Tornado in LYON, KENTUCKY
From 10-DEC-21 21:58:00 to 10-DEC-21 22:14:00 (CST-6)
Location: EUREKA
Tornado F-scale: EF3
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell). This tornado crossed from Marshall County into Lyon County, Kentucky near the Hillman Ferry Campground in the Land Between the Lakes National Recreation Area. The tornado crossed the Trace Highway causing near complete tree destruction and broke one wooden electrical transmission line (DI 24, DOD 4). The tornado achieved its highest rating of EF-3 as it emerged from Lake Barkley just north of Eddy Creek. Numerous homes were completely destroyed (DI 2, DOD 9) between the shore and Interstate 24 near Mile Marker 46. The damage rating of a house in this area corresponded with a wind speed of 150 mph, the highest in the county. The tornado continued to the county line producing mainly tree damage with occasional structural damage. A 98-year-old female occupant died of injuries incurred in her home south of Eddyville.  In addition, 5 others were injured throughout Lyon county. A total of 141 structures were affected in Lyon County, with 45 of those totally destroyed or uninhabitable. Nearly total tree destruction was observed in the Land Between the Lakes area. The average path width was a mile. The tornado exited Lyon County into Caldwell County in a rural area about 7 miles east southeast of Eddyville.

Thunderstorm Wind in TODD, KENTUCKY
From 11-DEC-21 00:37:00 to 11-DEC-21 00:43:00 (CST-6)
Location: ELKTON
Magnitude: 100.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The long-track tornado that ended in western Todd County transitioned to a damaging wind event near Elkton. On the west side of Elkton, a barn roof was damaged, several house roofs were damaged, and dozens of trees were snapped or uprooted. The most intense damage was observed on the northeast side of Elkton, where steel poles for electrical transmission lines were broken or bent. Peak winds there were estimated near 115 mph. Elsewhere northeast of Elkton, a barn was destroyed. Most of the other damage consisted of roof damage to barns and outbuildings, mostly minor. Numerous trees were blown down.

Tornado in GRAVES, KENTUCKY
From 10-DEC-21 21:16:00 to 10-DEC-21 21:40:00 (CST-6)
Location: BALTIMORE
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on the beginning of this tornado). This tornado crossed from Hickman County into Graves County about one-half mile north of where Highway 58 crosses the county line, close to the tiny community of Baltimore. The tornado was about 1.3 miles wide when it entered the county. It varied from 1 to 1.3 miles in width as it traversed Graves County. The primary impact to Graves County was on the city of Mayfield, where the tornado achieved a rating of EF-4. This city suffered a devastating impact, in terms of both loss of life and property destruction. There were 23 fatalities countywide and many more injuries. On the southwest edge of Mayfield as the tornado entered the city, a candle factory was demolished (DI 23, DOD 7). At least nine workers in the factory were killed. The tornado continued northeast through the heart of Mayfield at 9:28 PM CST, averaging just over one mile in width. The downtown area was directly impacted, crippling the police and fire department headquarters and emergency communications. Residential neighborhoods both southwest and northeast of downtown were destroyed. Numerous businesses in the downtown business district collapsed. Several damage sites in the city of Mayfield received a wind speed estimate of 188 mph, the highest in the county. Many of the structures were historic brick buildings (DI 17, DOD 7). At least 1,500 structures were damaged or destroyed, including a couple hundred businesses. The Red Cross estimated that 730 dwellings were uninhabitable. A large number of vehicles were thrown and destroyed, including some farm equipment in rural areas outside the city. Nearly total tree destruction was observed. The first EF-4 damage in the county was noted at and around the candle factory on the southwest side of Mayfield. Near the candle factory, a house was swept clean off the concrete slab (DI 2, DOD 10). The last EF-4 damage points in the county were on the northeast side of Mayfield, including a nursing home (DI 7, DOD 7). After entering Graves County, the tornado intersected I-69 (formerly the Purchase Parkway) four miles southwest of the Mayfield city limit. A wind gust to 93 knots or 107 mph was measured at the University of Kentucky mesonet site 6 miles southwest of Mayfield. The tornado then closely followed Interstate 69 northeast all the way to Marshall County. The tornado crossed the interstate multiple times. The first crossing was two miles southwest of Mayfield, then again northeast of Mayfield just east of the Highway 131 interchange, and again at the Marshall County line. The interstate was blocked in spots by trees, power lines, and debris. From Highway 131 to Highway 301 northeast of Mayfield, the tornado followed the exact same path as the May 10, 2016 EF-3 tornado. Some of the same structures that were damaged in that tornado were destroyed by this tornado. The tornado exited Graves County into Marshall County along Interstate 69 (formerly the Purchase Parkway) where it crosses the county line.

Hail in FULTON, KENTUCKY
From 10-DEC-21 20:55:00 to 10-DEC-21 20:55:00 (CST-6)
Location: HICKMAN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in CALDWELL, KENTUCKY
From 10-DEC-21 22:14:00 to 10-DEC-21 22:32:00 (CST-6)
Location: DULANEY
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell). The tornado crossed from Lyon County into Caldwell County in a rural area about 7 miles east southeast of Eddyville. The tornado crossed the Princeton Golf and Country Club resulting in collapsed walls of nearby homes (DI 2, DOD 10). This is where it achieved its highest rating of EF-4. A house near this country club received the highest wind speed estimate in the county, which was 180 mph. The tornado crossed southeast of Princeton, destroying large sections of the University Of Kentucky Research and Education Center (DI 15, DOD 10). The tornado then damaged many homes and trees near and just south of U.S. Highway 62 (Dawson Road). Just southwest of the intersection of US 62 and CR 2619, the tornado took a more easterly path (or rightward jog), continuing to damage homes along U.S. Highway 62 (Dawson Road) (DI 2, DOD 9). Two of the fatalities occurred at permanent homes on Dawson Road. The tornado trajectory then shifted back to northeast (or leftward jog), after which it crossed into Hopkins County on the southwest side of Dawson Springs. There were four fatalities in Caldwell County, with 11 others injured, 3 critically. All four of the deceased were found outside their residences. A couple who resided in a mobile home were both killed between Princeton and Dawson Springs. In total, around 300 structures were completely destroyed. The average path width was a mile.

Hail in GRAVES, KENTUCKY
From 10-DEC-21 21:24:00 to 10-DEC-21 21:24:00 (CST-6)
Location: MAYFIELD
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tornado in CALLOWAY, KENTUCKY
From 10-DEC-21 23:49:00 to 10-DEC-21 23:50:00 (CST-6)
Location: NEW CONCORD
Tornado F-scale: EF1
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This long-track EF-3 tornado began in western Tennessee near Dyersburg (see Storm Data, Tennessee, Western). It crossed from the northeast corner of Henry County, Tennessee and barely clipped the Fort Heiman section of the Fort Donelson National Battlefield in the southeast extremity of Calloway County. There were numerous uprooted trees near the Kentucky Lake shoreline. Because much of the path remained over the waters of Kentucky Lake during its extremely brief time in Calloway County, the intensity and the path width are both very uncertain. The center of the tornado crossed Kentucky Lake into Stewart County, Tennessee (see Storm Data, Tennessee, Central) and then back into western KY in Christian County (see Storm Data, Kentucky, Western).

Tornado in CHRISTIAN, KENTUCKY
From 11-DEC-21 00:10:00 to 11-DEC-21 00:32:00 (CST-6)
Location: LA FAYETTE
Tornado F-scale: EF2
Crop damage: 0.00K
Reported by: NWS Storm Survey

This long-track EF-3 tornado began in western Tennessee near Dyersburg (see Storm Data, Tennessee, Western). It crossed from Stewart County, Tennessee into Christian County in the secured area of the Fort Campbell military reservation (see Storm Data, Tennessee, Central for the Stewart County portion of the track). The tornado passed only about half a mile southeast of the community of La Fayette on its way northeast across Interstate 24 and Fort Campbell Boulevard (U.S. Highway 41). Between La Fayette and I-24, several homes were destroyed (DI 2, DOD 6). The homes suffered complete destruction of the roof and/or attic. The walls were often damaged but remained standing. One house was moved from its foundation (DI 2, DOD 5). The occupants of the houses took shelter and generally escaped serious injury. A mobile home was destroyed (DI 3, DOD 9). A church sustained steeple damage. Significant damage occurred to the silos and irrigation system of a farm, where damage was estimated near 1 million dollars. A mile's worth of power poles were snapped on Fort Campbell Boulevard (U.S. 41) just one to two miles north of the I-24 interchange (DI 24, DOD 4). After crossing U.S. 41, the tornado struck Pembroke, where more significant structural damage occurred. A single-wide mobile home was destroyed (DI 3, DOD 9). The mobile home was not tied down. One person was injured at this site. At least one other mobile home was destroyed. Two barns were destroyed (DI 1, DOD 8). Roofs were completely removed from two houses. Elsewhere along the path east of Fort Campbell Boulevard, farm outbuildings and farm equipment were damaged or destroyed. The tornado was rated EF-2 in Christian County. Several damage sites were assigned a wind speed estimate of 125 mph, the highest in the county. The average path width in Christian County was about a mile, though it narrowed to about three-quarters of a mile toward the end of its life after crossing Highway 41. The tornado continued northeast of Pembroke before entering Todd County.

Tornado in MARSHALL, KENTUCKY
From 10-DEC-21 21:40:00 to 10-DEC-21 21:58:00 (CST-6)
Location: HARVY
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on the beginning of this tornado). This tornado crossed from Graves County into Marshall County along Interstate 69 about seven miles west-southwest of Benton. The tornado  widened to nearly 1.5 miles (2450 yards) soon after crossing into Marshall County. The tornado width fluctuated from 0.8 mile to nearly 1.5 miles during its trek across the county. The community most impacted was Cambridge Shores, a rather dense subdivision of vacation homes and some luxury homes on Kentucky Lake. This is the only location in Marshall County where the tornado achieved a rating of EF-4. This community was the site of the only fatalities in Marshall County. A 78-year-old female resident died in the hallway of her house. Another elderly woman died of a heart attack while trying to remove debris (indirect). There were numerous homes in Cambridge Shores that were levelled, including the loss of all walls (DI 2, DOD 9). Some homes were wiped off the foundation. Marshall County's highest wind speed estimate of 170 mph was assigned to the damage in the Cambridge Shores area. A total of 356 structures in Marshall County were destroyed or uninhabitable. Another 341 structures sustained light to moderate damage. A number of vehicles were thrown and destroyed, including some that landed in Kentucky Lake. Nearly total tree destruction was observed in the Cambridge Shores area. After crossing into Marshall County, the tornado path stayed over Interstate 69 from the county line to about three miles west of Benton. In this area a few miles west of Benton, a home was blown off its foundation and a few other homes were demolished (DI 2, DOD 9). The tornado narrowly missed the county seat of Benton, passing only a mile or two northwest of the downtown area. Where the tornado crossed U.S. 641 just north of Benton, a home was destroyed with the exception of some interior walls (DI 2, DOD 8). The tornado crossed U.S. Highway 68 about one mile southeast of the county high school, then continued on to Cambridge Shores. The tornado exited Marshall County into Lyon County over Kentucky Lake, about 1.5 miles east-northeast of Cambridge Shores.

Tornado in HOPKINS, KENTUCKY
From 10-DEC-21 22:32:00 to 10-DEC-21 22:55:00 (CST-6)
Location: DAWSON SPGS
Tornado F-scale: EF4
Crop damage: 0.00K
Reported by: NWS Storm Survey

This historic EF-4 tornado was associated with a very long-track supercell that originally formed over eastern Arkansas. The supercell produced a nearly continuous tornado damage path from northeast Arkansas across western Tennessee and western Kentucky. The starting point of this particular tornado was in northwest Tennessee, northwest of Union City (see Storm Data, Tennessee, Western for information on this and other tornadoes associated with the supercell).  This tornado crossed from Caldwell County into Hopkins County near the city limit of Dawson Springs, which straddles the county line. The tornado produced catastrophic damage and some fatalities in Dawson Springs. About two-thirds of the city's homes were destroyed, and about a dozen fatalities occurred. There were at least 200 injuries. The core of the tornado narrowly missed the downtown Dawson Springs business district, but a large residential neighborhood on the north side of downtown was destroyed. This neighborhood is where the tornado obtained its maximum EF-4 rating in Hopkins County. A two-story apartment building was almost totally destroyed. Only a few first-story interior walls remained standing (DI 5, DOD 6). This apartment building is where the damage was assigned a wind speed estimate of 180 mph, the highest in the county. On the northern edge of town, over a dozen duplexes suffered complete roof loss. All exterior and interior walls of one of the units collapsed (DI 2, DOD 9). Most of the single-family homes suffered complete roof loss and the loss of most exterior walls (DI 2, DOD 8). In a few cases, there was complete destruction of residences (DI 2, DOD 10). On Highway 109 on the northeast side of town, a large retail structure with a long-span roof was destroyed (DI 12, DOD 7). Nearby, about a half dozen other smaller homes and businesses were demolished, including the loss of all walls (DI 9, DOD 9). Once the tornado exited the Dawson Springs area, it crossed Interstate 69 (formerly the Western Kentucky Parkway) about three miles northeast of Dawson Springs. A clearly defined wide path of nearly total tree destruction crossed the interstate. A house near the interstate suffered the loss of the roof and most walls, except for a few walls of small interior rooms (DI 2, DOD 8). Where the tornado crossed Highway 112, a few single-family homes were demolished, including the loss of the roof and all or most walls (DI 2, DOD 8-9). The tornado continued across heavily forested land until reaching Barnsley, a small community between Earlington and Mortons Gap on U.S. Highway 41. Several houses were demolished, including the loss of all walls (DI 2, DOD 9). In addition, a train was derailed and a 55-foot tanker car was thrown 20 yards from the railroad tracks (DI 29, DOD 1). The tornado then continued through a long swath of forest before crossing Interstate 69 midway between Madisonville and the Western Kentucky Parkway. Hundreds of trees were snapped at this interstate crossing (DI 27, DOD 4). A number of vehicles were thrown and destroyed across the county. The total number of affected structures countywide was estimated near 1000. A little over 500 structures were completely destroyed. Nearly total tree destruction was observed all along the path. The average path width was a mile. The tornado exited Hopkins County across the Pond River into Muhlenberg County about 6.5 miles east-southeast of Madisonville.