As a warm front lifted north through the forecast area, thunderstorms developed. Some of the storms became severe with numerous reports of large hail, some damaging winds and an EF2 tornado that occurred near Bourbon and Sullivan Missouri during the evening. The most costly damage occurred from a pair of supercells that dropped baseball to softball size hail across St. Charles County Missouri and produced severe wind gusts in St. Louis County and the City of St. Louis around the lunch hour.  There were also a few reports of flash flooding with these storms.

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 12:05:00 to 11-MAY-16 12:05:00 (CST-6)
Location: HOUSE SPGS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ST. LOUIS, MISSOURI
From 11-MAY-16 12:20:00 to 11-MAY-16 12:50:00 (CST-6)
Location: CHESTERFIELD
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A wide swath of large hail up to golf ball size fell in an area from western St. Louis County to northern parts of St. Louis County. The cities that reported the large hail were Chesterfield, Maryland Heights, Bridgeton, Hazelwood and just north of Dellwood.

Hail in WASHINGTON, MISSOURI
From 11-MAY-16 18:35:00 to 11-MAY-16 18:35:00 (CST-6)
Location: CRUISE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in ST. CHARLES, MISSOURI
From 11-MAY-16 19:07:00 to 11-MAY-16 19:08:00 (CST-6)
Location: COTTLEVILLE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down numerous large tree limbs in St. Peters and Harvester areas.

Hail in ST. LOUIS, MISSOURI
From 11-MAY-16 12:25:00 to 11-MAY-16 12:25:00 (CST-6)
Location: TIMES BEACH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in ST. LOUIS, MISSOURI
From 11-MAY-16 12:38:00 to 11-MAY-16 12:55:00 (CST-6)
Location: FERGUSON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorm winds blew down several large trees. One tree was blown down in Ferguson blocking a roadway. Another tree was blown down in Spanish Lake Park blocking one of the roads in the park.

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 12:25:00 to 11-MAY-16 12:45:00 (CST-6)
Location: MAXVILLE
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A wide swath of large hail fell over Jefferson County. Most of the large hail was between 1 inch and 1.75 inches in diameter. Large hail was reported in Arnold, Kimmswick, Imperial, and Pevely. The largest hailstones reported fell in Arnold which were 2.5 inches in diameter.

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 13:15:00 to 11-MAY-16 13:16:00 (CST-6)
Location: FESTUS
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in ST. FRANCOIS, MISSOURI
From 11-MAY-16 18:00:00 to 12-MAY-16 02:00:00 (CST-6)
Location: DAVIS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Up to four inches of rain fell in a short amount of time causing flash flooding. Numerous roads were flooded, including several streets in Park Hills.

Hail in CRAWFORD, MISSOURI
From 11-MAY-16 19:08:00 to 11-MAY-16 19:10:00 (CST-6)
Location: BOURBON
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 19:15:00 to 11-MAY-16 19:30:00 (CST-6)
Location: DE SOTO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 19:56:00 to 11-MAY-16 20:05:00 (CST-6)
Location: HEMATITE
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CALLAWAY, MISSOURI
From 11-MAY-16 16:47:00 to 11-MAY-16 16:50:00 (CST-6)
Location: AUXVASSE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in GASCONADE, MISSOURI
From 11-MAY-16 16:45:00 to 11-MAY-16 16:45:00 (CST-6)
Location: HERMANN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in WASHINGTON, MISSOURI
From 11-MAY-16 17:03:00 to 11-MAY-16 17:21:00 (CST-6)
Location: MINERAL PT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MONTGOMERY, MISSOURI
From 11-MAY-16 17:20:00 to 11-MAY-16 17:20:00 (CST-6)
Location: WELLSVILLE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds blew down several trees around town.

Hail in MONTGOMERY, MISSOURI
From 11-MAY-16 17:26:00 to 11-MAY-16 17:26:00 (CST-6)
Location: WELLSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Hail in WASHINGTON, MISSOURI
From 11-MAY-16 14:25:00 to 11-MAY-16 14:35:00 (CST-6)
Location: SHIRLEY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in JEFFERSON, MISSOURI
From 11-MAY-16 12:25:00 to 11-MAY-16 12:25:00 (CST-6)
Location: SECKMAN
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds blew down a large tree.

Hail in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 15:45:00 to 11-MAY-16 15:45:00 (CST-6)
Location: BLOOMSDALE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in ST. LOUIS, MISSOURI
From 11-MAY-16 12:30:00 to 11-MAY-16 12:40:00 (CST-6)
Location: BRECKENRIDGE HILLS
Magnitude: 56.00 EG
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A line of severe storms moved through St. Louis County. There were numerous reports of trees, tree limbs and power lines blown down in Bridgeton, St. Ann, Overland, Olivette, University City and Richmond Heights.  One tree was blown onto a house at the intersection of St. Henry and St. Sebastian Lanes and another one onto a house at the intersection of Ashby Road and San Carlos Lane, both in St. Ann. One of the homes was destroyed and the other sustained moderate damage.  No injuries were reported.

Tornado in CRAWFORD, MISSOURI
From 11-MAY-16 19:15:00 to 11-MAY-16 19:28:00 (CST-6)
Location: BOURBON
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down along Highway N, 3 miles south-southeast of Bourbon at 8:15 PM CDT causing significant tree damage.  A convergent pattern to the uprooted trees was apparent in this location with the rating of EF-1. The tornado continued northeast causing additional tree damage along Plum Tree Road that was rated
EF-0 and EF-1. It strengthened just to the southwest of Rock Road, directly hitting a single story house.  It appears the roof was lifted off the house and then the walls collapsed. Significant tree damage, including splitting, topping was noted along Rock Road. The damage in this area was rated EF-2 with maximum winds of 130 MPH.
Debris from the house, including receipts and roofing, were found up to 2.5 miles to the northeast. The tornado continued northeast, but weakened some as it encountered the next residence along Highway FF. Several outbuildings were destroyed at this location, along with roof and chimney damage to the main residence. This damage was rated EF-1.  The tornado crossed the highway and entered a quarry where several buildings suffered roof damage. The tornado
strengthened one last time south of Sullivan before dissipating. Hundreds of trees were snapped, twisted and uprooted on a large farm with a very distinct swirling motion observed near the main residence. This damage was rated EF-2 due to the complete leveling of the forest in this location.  The tornado quickly dissipated
3 miles southeast of Sullivan before Highway D at 8:28 PM CDT. The county sheriff flew in a helicopter along the path of the tornado, reporting that a total of eight houses were damaged, one destroyed. Overall the tornado was rated EF2 with a path length of 4.43 miles and a max path width of 700 yards.

Thunderstorm Wind in WASHINGTON, MISSOURI
From 11-MAY-16 20:00:00 to 11-MAY-16 20:00:00 (CST-6)
Location: RICHWOODS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm winds blew the roof off of a mobile home.  No one was injured.

Hail in AUDRAIN, MISSOURI
From 11-MAY-16 09:15:00 to 11-MAY-16 09:15:00 (CST-6)
Location: THOMPSON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm Wind in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 15:45:00 to 11-MAY-16 15:45:00 (CST-6)
Location: BLOOMSDALE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds blew down several large trees around town.

Hail in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 15:55:00 to 11-MAY-16 15:55:00 (CST-6)
Location: STE GENEVIEVE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in MONTGOMERY, MISSOURI
From 11-MAY-16 17:45:00 to 11-MAY-16 17:45:00 (CST-6)
Location: HIGH HILL
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds snapped off a power pole in town.

Thunderstorm Wind in LINCOLN, MISSOURI
From 11-MAY-16 17:45:00 to 11-MAY-16 17:45:00 (CST-6)
Location: TRUXTON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds blew down several trees and numerous large tree limbs around town.

Hail in MARION, MISSOURI
From 11-MAY-16 18:00:00 to 11-MAY-16 18:00:00 (CST-6)
Location: HANNIBAL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WARREN, MISSOURI
From 11-MAY-16 18:05:00 to 11-MAY-16 18:05:00 (CST-6)
Location: WARRENTON
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds blew down a couple of trees onto Highway U.

Hail in RALLS, MISSOURI
From 11-MAY-16 18:00:00 to 11-MAY-16 18:05:00 (CST-6)
Location: NEW LONDON
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CALLAWAY, MISSOURI
From 11-MAY-16 20:29:00 to 11-MAY-16 20:29:00 (CST-6)
Location: MILLERSBURG
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in JEFFERSON, MISSOURI
From 11-MAY-16 16:30:00 to 11-MAY-16 18:00:00 (CST-6)
Location: FLUCOM
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Up to four inches of rain fell in a short amount of time causing flash flooding.  Several roads were flooded including Highway T southeast of Olympian Village.

Thunderstorm Wind in AUDRAIN, MISSOURI
From 11-MAY-16 09:15:00 to 11-MAY-16 09:15:00 (CST-6)
Location: THOMPSON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorm winds blew down several large limbs on Route D just east of intersection with Route DD.

Hail in AUDRAIN, MISSOURI
From 11-MAY-16 09:35:00 to 11-MAY-16 09:35:00 (CST-6)
Location: ORTIZ
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in WASHINGTON, MISSOURI
From 11-MAY-16 20:13:00 to 12-MAY-16 01:30:00 (CST-6)
Location: CRUISE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Up to four inches of rain in a short amount of time caused flash flooding across the northern portions of Washington County. Several water rescues had to be performed around the Richwoods area. Numerous roads were closed due to flooding including Highway 47 near Richwoods. Four people were treated for minor injuries.

Thunderstorm Wind in ST. LOUIS (C), MISSOURI
From 11-MAY-16 12:39:00 to 11-MAY-16 12:50:00 (CST-6)
Location: TOWER GROVE
Magnitude: 56.00 EG
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

As the line of severe storms moved through St. Louis, there were numerous large trees blown down on the west side of town in and around Forest Park.  One large tree was blown down in the 6900 block of Dale Avenue, landing on 3 homes. One sustained major damage with the back half of the home crushed. No one was home at the time, but their dog was briefly trapped and was rescued unharmed. The two other homes hit sustained moderate damage. Also, several large trees were blown down in Tower Grove Park area. One large tree landed on an unoccupied pickup truck, destroying it.

Hail in CALLAWAY, MISSOURI
From 11-MAY-16 09:35:00 to 11-MAY-16 09:35:00 (CST-6)
Location: BRYANS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in AUDRAIN, MISSOURI
From 11-MAY-16 10:00:00 to 11-MAY-16 10:00:00 (CST-6)
Location: FARBER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in PIKE, MISSOURI
From 11-MAY-16 10:45:00 to 11-MAY-16 10:45:00 (CST-6)
Location: CYRENE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 16:33:00 to 11-MAY-16 16:33:00 (CST-6)
Location: ST MARYS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 15:55:00 to 11-MAY-16 16:05:00 (CST-6)
Location: STE GENEVIEVE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds blew down several large trees around town. One large tree fell onto U.S. Highway 61, blocking one lane.

Hail in ST. FRANCOIS, MISSOURI
From 11-MAY-16 15:50:00 to 11-MAY-16 16:14:00 (CST-6)
Location: BONNE TERRE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A wide swath of large hail fell from Bonne Terre south to Desloge and Park Hills.

Hail in ST. CHARLES, MISSOURI
From 11-MAY-16 11:50:00 to 11-MAY-16 12:20:00 (CST-6)
Location: ST CHARLES
Magnitude: 4.00 
Property damage: 4.00M
Crop damage: 0.00K
Reported by: NWS Employee

Very large hail up to 4 inches in diameter fell across portions of St. Charles County.  The hardest hit areas stretched from near Dardenne Prairie, O'Fallon and Weldon Spring east to Cottleville, St. Peters and St. Charles.   Damage from this hail storm will be many millions of dollars as thousands of homes, vehicles and businesses were impacted and suffered damage.  One hundred twenty cars at a car dealership near the intersection of I-64/Highway 94, sustained busted windows and lots of dents from large hail, some that were as big as baseballs. Reports of windows blown out, roofing and siding damage were common.

Hail in ST. FRANCOIS, MISSOURI
From 11-MAY-16 17:00:00 to 11-MAY-16 17:35:00 (CST-6)
Location: CANTWELL
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A wide swath of large hail fell in the Desloge, Park Hills and Leadington areas for 35 minutes.  Numerous vehicles and vehicles sustained damage from the hail.

Hail in LINCOLN, MISSOURI
From 11-MAY-16 18:17:00 to 11-MAY-16 18:17:00 (CST-6)
Location: TROY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FRANKLIN, MISSOURI
From 11-MAY-16 18:25:00 to 11-MAY-16 18:25:00 (CST-6)
Location: UNION
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FRANKLIN, MISSOURI
From 11-MAY-16 18:50:00 to 11-MAY-16 18:50:00 (CST-6)
Location: LABADIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in WARREN, MISSOURI
From 11-MAY-16 11:37:00 to 11-MAY-16 11:37:00 (CST-6)
Location: DUTZOW
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in JEFFERSON, MISSOURI
From 11-MAY-16 12:10:00 to 11-MAY-16 12:10:00 (CST-6)
Location: OTTO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ST. LOUIS, MISSOURI
From 11-MAY-16 11:40:00 to 11-MAY-16 11:40:00 (CST-6)
Location: EUREKA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in FRANKLIN, MISSOURI
From 11-MAY-16 19:17:00 to 11-MAY-16 19:17:00 (CST-6)
Location: ST CLAIR
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in STE. GENEVIEVE, MISSOURI
From 11-MAY-16 18:35:00 to 11-MAY-16 18:35:00 (CST-6)
Location: WEINGARTEN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Golfball size hail fell at Hawn State Park.

Hail in ST. LOUIS, MISSOURI
From 11-MAY-16 12:43:00 to 11-MAY-16 12:45:00 (CST-6)
Location: UNIVERSITY CITY
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ST. LOUIS, MISSOURI
From 11-MAY-16 12:45:00 to 11-MAY-16 12:45:00 (CST-6)
Location: OAKVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in AUDRAIN, MISSOURI
From 11-MAY-16 16:24:00 to 11-MAY-16 16:38:00 (CST-6)
Location: MEXICO
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail up to baseball size fell across the Mexico area causing damage to numerous vehicles.

Thunderstorm Wind in ST. FRANCOIS, MISSOURI
From 11-MAY-16 17:20:00 to 11-MAY-16 17:20:00 (CST-6)
Location: ESTHER
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds blew down several large trees in Park Hills.

Hail in CRAWFORD, MISSOURI
From 11-MAY-16 16:12:00 to 11-MAY-16 16:12:00 (CST-6)
Location: CUBA AIRSTRIP ARPT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BOONE, MISSOURI
From 11-MAY-16 16:20:00 to 11-MAY-16 16:20:00 (CST-6)
Location: CENTRALIA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CALLAWAY, MISSOURI
From 11-MAY-16 16:45:00 to 11-MAY-16 16:45:00 (CST-6)
Location: FULTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in JEFFERSON, MISSOURI
From 11-MAY-16 12:35:00 to 11-MAY-16 12:35:00 (CST-6)
Location: ARNOLD
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds blew down several large trees and numerous power lines in an area between Arnold and Imperial.