Numerous severe thunderstorms formed ahead of an approaching cold front during the late afternoon and evening of Friday December 10th, 2021.  Large hail, damaging winds and five tornadoes occurred across central and eastern Missouri as well as south central Illinois.  Unfortunately two of the tornadoes were very strong (rated EF-3 on the Enhanced Fujita Scale) and responsible for 7 fatalities (one near Defiance, Missouri and six at an Amazon Facility near Edwardsville, Illinois). The Defiance, MO tornado tracked within one mile of the NWS St. Louis office in the Missouri Research Park near Weldon Spring, MO leading to the staff sheltering while NWS Kansas City provided service backup.  This is only the third time in the office's existence that the staff had to shelter. The damage from the Defiance, MO EF3 tornado was estimated at $684,186 and is unknown for the remaining tracks at this time but early estimates are well into the millions due to the damage sustained at the Amazon facility near Edwardsville, IL.

Thunderstorm Wind in ST. LOUIS, MISSOURI
From 10-DEC-21 19:56:00 to 10-DEC-21 20:00:00 (CST-6)
Location: (SUS)SPIRIT/ST LOUIS
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm winds blew down a large section of fence near Chesterfield Mall.

Thunderstorm Wind in BOONE, MISSOURI
From 10-DEC-21 18:13:00 to 10-DEC-21 18:19:00 (CST-6)
Location: DEER PARK
Magnitude: 52.00 MG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm winds blew down a large tree on Rock Quarry Road near intersection with Gans Road.

Thunderstorm Wind in CALLAWAY, MISSOURI
From 10-DEC-21 18:32:00 to 10-DEC-21 18:32:00 (CST-6)
Location: HOLTS SUMMIT
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew a large tree down at the intersection of State Highway AA and Platinum Road.

Thunderstorm Wind in COLE, MISSOURI
From 10-DEC-21 18:23:00 to 10-DEC-21 18:27:00 (CST-6)
Location: ST THOMAS
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm winds blew off part of a metal roof on a storage building in St. Thomas. Just southeast of Osage Bend, a large tree with a shallow root ball was tipped over. Also, numerous large tree limbs were snapped off.

Thunderstorm Wind in PIKE, MISSOURI
From 10-DEC-21 18:42:00 to 10-DEC-21 18:42:00 (CST-6)
Location: ASHBURN
Magnitude: 70.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Four large trees were blown down onto Highway 79 near the intersection with Route TT.

Thunderstorm Wind in GASCONADE, MISSOURI
From 10-DEC-21 18:51:00 to 10-DEC-21 18:56:00 (CST-6)
Location: MORRISON
Magnitude: 61.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread wind damage between Morrison and Gasconade. A number of trees were blown down onto Highway 100.

Tornado in MONTGOMERY, MISSOURI
From 10-DEC-21 18:55:00 to 10-DEC-21 19:00:00 (CST-6)
Location: WELLSVILLE
Tornado F-scale: EF0
Property damage: 25.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A weak tornado touched down just northwest of Wellsville east of Highway 19 where it broke several power poles. It then moved northeast toward the intersection of Morgan School Road and Route A and traveled northeast to Orchard Road. Minor tree damage and flattened corn was observed. The width of the tornado was around 50 yards, and the damage was rated EF-0. Interestingly, the WSR-88D identified debris (lowering correlation coefficient), likely from the lofted corn stalks. Overall, the tornado was rated EF0 with a path length of 4.27miles and max path width of 50 yards. No deaths or injuries were reported.

Thunderstorm Wind in FRANKLIN, MISSOURI
From 10-DEC-21 19:05:00 to 10-DEC-21 19:22:00 (CST-6)
Location: GERALD
Magnitude: 61.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a large tree across Highway Y near the intersection with Wheeler Road. Also, a large tree was blown down at the intersection of Evergreen Loop and Three Oaks Road.

Hail in WARREN, MISSOURI
From 10-DEC-21 19:29:00 to 10-DEC-21 19:29:00 (CST-6)
Location: MARTHASVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in ST. LOUIS, MISSOURI
From 10-DEC-21 19:51:00 to 10-DEC-21 19:53:00 (CST-6)
Location: (SUS)SPIRIT/ST LOUIS
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

After crossing into St. Louis County the tornado caused extensive tree damage along the river, a mere half mile from a large outlet mall. It crossed Highway 40/61/Interstate 64 east of the Boone Bridge causing minor damage to vehicles that were on the highway. The tornado continued northeast, crossing the Missouri River again, back into St. Charles County near Greens Bottom Road.

Thunderstorm Wind in AUDRAIN, MISSOURI
From 10-DEC-21 18:35:00 to 10-DEC-21 18:35:00 (CST-6)
Location: WORCHESTER
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a tree onto Highway J near the intersection with Highway B.

Thunderstorm Wind in FRANKLIN, MISSOURI
From 10-DEC-21 19:36:00 to 10-DEC-21 19:53:00 (CST-6)
Location: STANTON
Magnitude: 61.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread wind damage across Franklin County. A large tree was blown down onto roadway along St. Louis Inn Road about 5 miles southwest of St. Clair. Another large tree was blown down on to Highway 47 near intersection with Eastview Drive.  On the southwest side of Union, several power lines were blown down at the intersection of Koelling Avenue and West Springfield Avenue.  About 3 miles north northwest of Moselle, there were numerous trees damaged or uprooted, as well as damage to a car port, power lines blown down and damage to several roofs.  Several trees were blown over on the northwest side of Pacific.

Thunderstorm Wind in OSAGE, MISSOURI
From 10-DEC-21 18:26:00 to 10-DEC-21 18:45:00 (CST-6)
Location: WESTPHALIA
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread wind damage across Osage County. A roof was blown off of a storage building at the intersection of Highway 133 and County Road 503. Also, there were numerous trees blown down along Highway 133. A roof was blown off of a business on U.S. Highway 63 about two miles north of Westphalia. A large tree was blown down onto U.S. Highway 63 blocking both lanes. Just east of Loose Creek a home sustained minor damage and another home sustained minor damage from a trampoline being blown into it. Otherwise, numerous large tree limbs were blown down.

Thunderstorm Wind in CALLAWAY, MISSOURI
From 10-DEC-21 18:32:00 to 10-DEC-21 18:37:00 (CST-6)
Location: MC CREDIE
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Widespread wind damage across portions of Kingdom City and Fulton. A large tree was blown down onto Route FF near intersection with Old U.S. Highway 40, blocking the roadway. Also, a large tree was blown down onto a house in Fulton causing moderate roof damage. Numerous large tree limbs and several additional trees were blown down.

Thunderstorm Wind in LINCOLN, MISSOURI
From 10-DEC-21 19:40:00 to 10-DEC-21 19:40:00 (CST-6)
Location: WINFIELD
Magnitude: 61.00 EG
Property damage: 7.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several street lights were blown over in town.

Hail in ST. LOUIS, MISSOURI
From 10-DEC-21 20:00:00 to 10-DEC-21 20:00:00 (CST-6)
Location: BALLWIN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MADISON, MISSOURI
From 10-DEC-21 22:38:00 to 10-DEC-21 22:38:00 (CST-6)
Location: CHOBB STORE
Magnitude: 61.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm winds blew down a large tree onto Highway C, about 8 miles south southwest of Fredericktown.

Thunderstorm Wind in ST. CHARLES, MISSOURI
From 10-DEC-21 20:02:00 to 10-DEC-21 20:02:00 (CST-6)
Location: ORCHARD FARM
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in ST. LOUIS, MISSOURI
From 10-DEC-21 20:04:00 to 10-DEC-21 20:04:00 (CST-6)
Location: FERNRIDGE
Magnitude: 61.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds blew a large tree down onto an apartment building causing moderate damage.

Tornado in ST. CHARLES, MISSOURI
From 10-DEC-21 19:32:00 to 10-DEC-21 19:51:00 (CST-6)
Location: FEMME OSAGE
Tornado F-scale: EF3
Property damage: 3.40M
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado developed about a third of a mile northeast of the intersection of Highway 94 and Osage Ridge Road in southwestern St. Charles County around 7:32 PM CDT. As it moved to the northeast, two houses sustained minor damage and one outbuilding was destroyed on Highway T, just north of intersection with Hemsath Road. The tornado continued northeast and strengthened as it approached Highway F, northwest of Defiance. Multiple homesteads and farms suffered varying degrees of property damage along Highway F to Highway 94. Two homes were completely destroyed. The first home was 110 years old and did not appear to have any anchoring to the concrete foundation. The second home just 100 yards east of the first was swept clean to the subfloor, which was still anchored to the concrete foundation. One fatality and two injuries occurred at this location. The damage was rated EF3 with winds to 165 mph. The tornado continued northeast, crossing the Missouri River and Howell Island before entering St. Louis County in Chesterfield Valley. Dollar amount damage is estimated around $3.4 million.

Tornado in ST. LOUIS, MISSOURI
From 10-DEC-21 19:58:00 to 10-DEC-21 20:01:00 (CST-6)
Location: ST LOUIS CREVE COEUR
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Once back in St. Louis County, there was additional tree damage and other minor damage noted. The tornado lifted at 8:01 PM before entering the Hollywood Casino Amphitheatre Complex. Overall, the entire tornado (St. Charles/St. Louis counties) was rated EF3 with a path length of 27.30 miles and a max path width of 150 yards. There was one death and two injuries with this tornado. Dollar amount damage is estimated around $3.4 million in St. Charles County.

Tornado in ST. CHARLES, MISSOURI
From 10-DEC-21 19:53:00 to 10-DEC-21 19:58:00 (CST-6)
Location: WELDON
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

After crossing back into St. Charles County there was additional tree damage, broken power poles, and structural damage noted along Greens Bottom Road. The tornado crossed the Missouri River a third and final time, back into St. Louis County traveling across Highway 364 and north of the Creve Coeur Airport.

Thunderstorm Wind in FRANKLIN, MISSOURI
From 10-DEC-21 20:57:00 to 10-DEC-21 21:30:00 (CST-6)
Location: GERALD
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A wide swath of damaging winds across Franklin County. In Gerald, several phone and power lines were blown down in town. Several large trees and power lines were blown down on Camp Mo-Val Road, as well as North Bend Loop, southwest of Union. Additional power lines were blown down in St. Clair. About 3 miles west northwest of Robertsville, a large tree was blown over onto Highway O near intersection with Route AM.

Tornado in REYNOLDS, MISSOURI
From 10-DEC-21 22:05:00 to 10-DEC-21 22:11:00 (CST-6)
Location: REDFORD
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down around 10:05 PM CST to the northeast of Ellington, southwest of County Road 440, snapping numerous trees rated EF1 damage. The tornado proceeded east- northeast across Sinking Creek and damaged a house and single-wide trailer along County Road 428, as well as continuing to snap numerous trees. As the tornado continued east-northeast and crossed County Road 447, it intensified to an EF2 and completely tore off the roofs of two homes off of County Road 442 and County Road 442B. The home off of County Road 442B was where the most significant damage was observed, as it also lost an exterior wall. Two outbuildings were also destroyed by the tornado, and significant tree damage was observed. The tornado crossed the Black River and weakened, though it still caused EF1 damage to trees and power lines on County Road 456, where it lifted around 10:11 PM CST. Overall, the tornado was rated EF2 with a path length of 6.86 miles and max path width of 300 yards. No deaths or injuries were reported.