Severe thunderstorms pounded parts the Urban Corridor and Northeast Plains with very large hail, damaging wind and tornadoes.  The hail, ranging from golfball to baseball size, hit northeast Denver, Brighton and Commerce City the hardest.  The storms then continued to spread to the north and east; impacting Hudson, Prospect Valley, Byers and Deer Trail.   The strong thunderstorm wind and hail stripped bark and branches from trees.  Numerous accidents were reported as the hail accumulated up to a foot in depth on roadways.  Homes and vehicles in the area were pummeled by hail.   The Rocky Mountain Insurance Information Associated estimated to damage to be around $70 million; based off approximately 13,600 automobile and homeowner claims.  A child in Commerce City was struck in the leg by lightning while watching televison.  A bison and the Rocky Mountain Arsenal National Wildlife Refuge was struck and killed by blast of lightning.  Two tornadoes also touched down in open country; one near Denver International Airport and the other near Keenesburg.
The heavy rain and hail caused flash flooding to occur around the towns of Hudson and Keenseburg; forcing the closure of State Highway 52.  Extensive crop damage was reported across southern Weld County.  Approximately 1500 acres of sugar beets were damaged in the Prospect Valley and Windsor areas.  About 360 acres of sweet corn, cabbage and onions in the Hudson area were inundated with heavy rain and a torrent of hail.  In Windsor, a barn was demolished by intense thunderstorm winds.   The wind ripped the 40-ft by 40-ft structure of a garage and exterior corrugated roof and walls about 75 yards from its original foundation. Also, two cow shelters and 150 calf shelters were blown over.  Near Bellvue, several structures were knocked down and a 15-ft silo was blown across a field by damaging thunderstorm winds.

Hail in ADAMS, COLORADO
From 26-MAY-10 19:20:00 to 26-MAY-10 19:20:00 (MST-7)
Location: HENDERSON
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 19:40:00 to 26-MAY-10 19:40:00 (MST-7)
Location: HUDSON
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 17:21:00 to 26-MAY-10 17:21:00 (MST-7)
Location: VALLERY
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in ELBERT, COLORADO
From 26-MAY-10 17:00:00 to 26-MAY-10 17:00:00 (MST-7)
Location: LOWLAND
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 26-MAY-10 19:50:00 to 26-MAY-10 19:50:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 26-MAY-10 19:41:00 to 26-MAY-10 19:41:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 26-MAY-10 19:55:00 to 26-MAY-10 19:55:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.00 
Reported by: Trained Spotter

Tornado in WELD, COLORADO
From 26-MAY-10 14:30:00 to 26-MAY-10 14:30:00 (MST-7)
Location: KEENESBURG
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down in an open field; no damage was reported.

Lightning in ADAMS, COLORADO
From 26-MAY-10 12:30:00 to 26-MAY-10 12:30:00 (MST-7)
Location: COMMERCE CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A child was struck in the leg by lightning while watching television.

Tornado in DENVER, COLORADO
From 26-MAY-10 12:30:00 to 26-MAY-10 12:39:00 (MST-7)
Location: (DEN)DENVER INTL ARP
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down but did no damage.

Hail in BOULDER, COLORADO
From 26-MAY-10 20:04:00 to 26-MAY-10 20:04:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 20:04:00 to 26-MAY-10 20:04:00 (MST-7)
Location: FT LUPTON
Magnitude: 1.75 
Reported by: Trained Spotter

Thunderstorm Wind in WELD, COLORADO
From 26-MAY-10 14:12:00 to 26-MAY-10 14:12:00 (MST-7)
Location: WINDSOR
Magnitude: 70.00 EG
Property damage: 190.00K
Reported by: Newspaper

Intense thunderstorm winds caused extensive damage to the exterior of a garage shop along with scores of livestock shelters.

Hail in WELD, COLORADO
From 26-MAY-10 20:16:00 to 26-MAY-10 20:16:00 (MST-7)
Location: HUDSON ARPT
Magnitude: 1.25 
Reported by: Trained Spotter

Lightning in ADAMS, COLORADO
From 26-MAY-10 13:00:00 to 26-MAY-10 13:00:00 (MST-7)
Location: COMMERCE CITY
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Newspaper

A lightning strike killed a buffalo at the Rocky Mountain Arsenal Refuge.

Hail in WELD, COLORADO
From 26-MAY-10 15:15:00 to 26-MAY-10 15:15:00 (MST-7)
Location: PROSPECT
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 13:09:00 to 26-MAY-10 13:09:00 (MST-7)
Location: BARR LAKE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 17:10:00 to 26-MAY-10 17:10:00 (MST-7)
Location: WIGGINS
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BROOMFIELD, COLORADO
From 26-MAY-10 19:17:00 to 26-MAY-10 19:17:00 (MST-7)
Location: BROOMFIELD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 18:24:00 to 26-MAY-10 18:24:00 (MST-7)
Location: FT MORGAN ARPT
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 17:14:00 to 26-MAY-10 17:14:00 (MST-7)
Location: WIGGINS
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 20:38:00 to 26-MAY-10 20:38:00 (MST-7)
Location: HUDSON ARPT
Magnitude: 1.00 
Reported by: Trained Spotter

Flash Flood in WELD, COLORADO
From 26-MAY-10 19:45:00 to 26-MAY-10 22:00:00 (MST-7)
Location: ROGGEN
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 50.00K
Reported by: Emergency Manager

The combination of very heavy rain and large hail produced flash flooding along State Highway 52 near Hudson and Keenseburg.  Up to 18 inches of water flowed across sections of the highway, damaging the roadway.  The most severe damage was reported at the intersection of State Highway 52 and County Road 49.  Extensive crop damage was also reported in the area.  The highway remained closed until the floodwaters subsided.

Hail in ADAMS, COLORADO
From 26-MAY-10 18:33:00 to 26-MAY-10 18:33:00 (MST-7)
Location: HAZELTINE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in LARIMER, COLORADO
From 26-MAY-10 14:14:00 to 26-MAY-10 14:14:00 (MST-7)
Location: TIMNATH
Magnitude: 70.00 EG
Reported by: Trained Spotter

Several small structures were knocked down and a silo blown across a field.

Hail in WELD, COLORADO
From 26-MAY-10 15:34:00 to 26-MAY-10 15:34:00 (MST-7)
Location: ROGGEN
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:48:00 to 26-MAY-10 12:48:00 (MST-7)
Location: HAZELTINE
Magnitude: 1.75 
Reported by: Trained Spotter

Thunderstorm Wind in WELD, COLORADO
From 26-MAY-10 14:06:00 to 26-MAY-10 14:06:00 (MST-7)
Location: NUNN
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 14:30:00 to 26-MAY-10 14:30:00 (MST-7)
Location: TONVILLE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:55:00 to 26-MAY-10 12:55:00 (MST-7)
Location: BARR LAKE
Magnitude: 1.75 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 26-MAY-10 12:30:00 to 26-MAY-10 12:30:00 (MST-7)
Location: HAZELTINE
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in ELBERT, COLORADO
From 26-MAY-10 16:16:00 to 26-MAY-10 16:16:00 (MST-7)
Location: KIOWA
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:48:00 to 26-MAY-10 12:48:00 (MST-7)
Location: THORNTON
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 17:01:00 to 26-MAY-10 17:01:00 (MST-7)
Location: WIGGINS
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 14:32:00 to 26-MAY-10 14:32:00 (MST-7)
Location: HUDSON
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in DENVER, COLORADO
From 26-MAY-10 13:02:00 to 26-MAY-10 13:02:00 (MST-7)
Location: (DEN)DENVER INTL ARP
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 16:27:00 to 26-MAY-10 16:27:00 (MST-7)
Location: WIGGINS
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 14:54:00 to 26-MAY-10 14:54:00 (MST-7)
Location: KEENESBURG
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 26-MAY-10 17:01:00 to 26-MAY-10 17:01:00 (MST-7)
Location: WIGGINS
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:31:00 to 26-MAY-10 12:31:00 (MST-7)
Location: HAZELTINE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:49:00 to 26-MAY-10 12:49:00 (MST-7)
Location: COMMERCE CITY
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:33:00 to 26-MAY-10 12:33:00 (MST-7)
Location: COMMERCE CITY
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:50:00 to 26-MAY-10 12:50:00 (MST-7)
Location: WELBY
Magnitude: 1.00 
Reported by: NWS Employee

Hail in WELD, COLORADO
From 26-MAY-10 15:14:00 to 26-MAY-10 15:14:00 (MST-7)
Location: ROGGEN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:40:00 to 26-MAY-10 12:40:00 (MST-7)
Location: WELBY
Magnitude: 1.00 
Reported by: NWS Employee

Hail in WELD, COLORADO
From 26-MAY-10 13:45:00 to 26-MAY-10 13:45:00 (MST-7)
Location: SEVERANCE
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:51:00 to 26-MAY-10 12:51:00 (MST-7)
Location: NORTHGLENN
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:45:00 to 26-MAY-10 12:45:00 (MST-7)
Location: BARR LAKE
Magnitude: 1.75 
Reported by: NWS Employee

Hail in MORGAN, COLORADO
From 26-MAY-10 16:35:00 to 26-MAY-10 16:35:00 (MST-7)
Location: WIGGINS
Magnitude: 1.75 
Reported by: Emergency Manager

Hail in WELD, COLORADO
From 26-MAY-10 15:20:00 to 26-MAY-10 15:20:00 (MST-7)
Location: PROSPECT
Magnitude: 2.00 
Reported by: Storm Chaser

Hail in ADAMS, COLORADO
From 26-MAY-10 12:51:00 to 26-MAY-10 12:51:00 (MST-7)
Location: BARR LAKE
Magnitude: 2.75 
Reported by: Law Enforcement

Hail in MORGAN, COLORADO
From 26-MAY-10 16:44:00 to 26-MAY-10 16:44:00 (MST-7)
Location: WIGGINS
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 26-MAY-10 13:50:00 to 26-MAY-10 13:50:00 (MST-7)
Location: TIMNATH
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:45:00 to 26-MAY-10 12:45:00 (MST-7)
Location: BRIGHTON
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 15:25:00 to 26-MAY-10 15:25:00 (MST-7)
Location: KEENESBURG
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 14:05:00 to 26-MAY-10 14:05:00 (MST-7)
Location: BARR LAKE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:53:00 to 26-MAY-10 12:53:00 (MST-7)
Location: BARR LAKE
Magnitude: 2.75 
Property damage: 70.00M
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 26-MAY-10 12:23:00 to 26-MAY-10 12:23:00 (MST-7)
Location: HAZELTINE
Magnitude: 2.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 26-MAY-10 20:10:00 to 26-MAY-10 20:10:00 (MST-7)
Location: FT LUPTON
Magnitude: 1.00 
Reported by: Trained Spotter