Severe thunderstorms brought damaging hail, wind, tornadoes, heavy rain and flash flooding to portions of the Urban Corridor and Northeast Plains.  Very large hail, ranging from quarter to softball size, caused extensive damage to property and crops.  Several small and brief non supercell tornadoes touched down but did little if any damage.  Most the damage was the result of the large hail, intense thunderstorm winds, heavy rain and flash flooding.  In Erie, a velodrome under construction was heavily damaged.

Tornado in WELD, COLORADO
From 03-AUG-13 15:17:00 to 03-AUG-13 15:17:00 (MST-7)
Location: GATES
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 5.00K
Reported by: Law Enforcement

A tornado touched down briefly.  Some damage was reported.

Tornado in WELD, COLORADO
From 03-AUG-13 16:24:00 to 03-AUG-13 16:24:00 (MST-7)
Location: KEENESBURG
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A tornado touched down briefly in an open field.  No damage was reported.

Thunderstorm Wind in WELD, COLORADO
From 03-AUG-13 16:55:00 to 03-AUG-13 16:55:00 (MST-7)
Location: ERIE
Magnitude: 59.00 MG
Reported by: AWOS

A velodrome under construction was heavily damaged by heavy rain and high winds.  The wind toppled the eastern third of the 250-meter cycling track. Bolts measuring one-half-inch thick by 7 1/2 inches in length were ripped out of concrete footers while 16-inch-wide trusses, collapsed under the force of the wind. In town, heavy rain, around 2.5 inches in less than one hour, caused extensive street flooding.  The intense wind also downed trees which resulted in localized power outages. In addition, an empty semi-trailer was blown on its side.

Thunderstorm Wind in BROOMFIELD, COLORADO
From 03-AUG-13 17:09:00 to 03-AUG-13 17:09:00 (MST-7)
Location: BROOMFIELD
Magnitude: 52.00 MG
Reported by: Mesonet

Tornado in MORGAN, COLORADO
From 03-AUG-13 13:00:00 to 03-AUG-13 13:03:00 (MST-7)
Location: FT MORGAN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tornado touched down briefly in an open field.  No damage was reported.

Thunderstorm Wind in ARAPAHOE, COLORADO
From 03-AUG-13 18:55:00 to 03-AUG-13 18:55:00 (MST-7)
Location: (BKF)BUCKLEY AIR FORCE BASE
Magnitude: 53.00 MG
Reported by: ASOS

Thunderstorm Wind in ADAMS, COLORADO
From 03-AUG-13 17:09:00 to 03-AUG-13 17:09:00 (MST-7)
Location: NORTHGLENN
Magnitude: 52.00 MG
Reported by: Mesonet

Thunderstorm Wind in WELD, COLORADO
From 03-AUG-13 16:47:00 to 03-AUG-13 16:47:00 (MST-7)
Location: ERIE
Magnitude: 56.00 MG
Reported by: Mesonet

Flash Flood in WASHINGTON, COLORADO
From 03-AUG-13 14:49:00 to 03-AUG-13 18:00:00 (MST-7)
Location: LAST CHANCE
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 50.00K
Reported by: Emergency Manager

Heavy rain producing thunderstorms caused extensive flooding of creeks and fields.  Numerous dirt roads were damaged or washed out completely.

Tornado in WELD, COLORADO
From 03-AUG-13 16:40:00 to 03-AUG-13 16:40:00 (MST-7)
Location: ERIE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tornado touched down briefly but did no damage.

Flash Flood in WELD, COLORADO
From 03-AUG-13 16:00:00 to 03-AUG-13 17:30:00 (MST-7)
Location: WINDSOR
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 50.00K
Reported by: Newspaper

Torrential rain and hail produced flash flooding in and around Greeley and Windsor.  The storm produced widespread flooding and inundated crops, county roads and city streets.  Numerous roadways were closed due to flood waters.  One woman had to be rescued when she was trapped in her vehicle by 3 ft of rushing water.  Several homes and basements were flooded when nearby ditches overflowed.

Hail in WELD, COLORADO
From 03-AUG-13 13:32:00 to 03-AUG-13 13:32:00 (MST-7)
Location: NUNN
Magnitude: 1.00 
Reported by: Amateur Radio

Hail in LARIMER, COLORADO
From 03-AUG-13 13:45:00 to 03-AUG-13 13:45:00 (MST-7)
Location: BUCKEYE
Magnitude: 4.00 
Reported by: Trained Spotter

Very large hail caused extensive damage to homes, automobiles and trees and crops.

Hail in LARIMER, COLORADO
From 03-AUG-13 13:55:00 to 03-AUG-13 13:55:00 (MST-7)
Location: BUCKEYE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 03-AUG-13 14:07:00 to 03-AUG-13 14:07:00 (MST-7)
Location: WELLINGTON
Magnitude: 2.75 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 03-AUG-13 14:17:00 to 03-AUG-13 14:17:00 (MST-7)
Location: WELLINGTON
Magnitude: 1.75 
Reported by: Amateur Radio

Hail in WELD, COLORADO
From 03-AUG-13 14:20:00 to 03-AUG-13 14:20:00 (MST-7)
Location: PIERCE
Magnitude: 1.75 
Reported by: Amateur Radio

Hail in LARIMER, COLORADO
From 03-AUG-13 14:21:00 to 03-AUG-13 14:21:00 (MST-7)
Location: WELLINGTON
Magnitude: 1.50 
Reported by: Amateur Radio

Hail in WELD, COLORADO
From 03-AUG-13 14:21:00 to 03-AUG-13 14:21:00 (MST-7)
Location: NUNN
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 03-AUG-13 14:41:00 to 03-AUG-13 14:41:00 (MST-7)
Location: AULT
Magnitude: 1.75 
Reported by: Law Enforcement

Hail in WELD, COLORADO
From 03-AUG-13 15:16:00 to 03-AUG-13 15:16:00 (MST-7)
Location: WINDSOR
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 03-AUG-13 15:21:00 to 03-AUG-13 15:21:00 (MST-7)
Location: WINDSOR
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 03-AUG-13 15:25:00 to 03-AUG-13 15:25:00 (MST-7)
Location: TIMNATH
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 03-AUG-13 15:30:00 to 03-AUG-13 15:30:00 (MST-7)
Location: EATON ARPT
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 03-AUG-13 15:43:00 to 03-AUG-13 15:43:00 (MST-7)
Location: GREELEY
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 03-AUG-13 15:48:00 to 03-AUG-13 15:48:00 (MST-7)
Location: BRUCE
Magnitude: 1.00 
Reported by: CoCoRaHS

Hail in WELD, COLORADO
From 03-AUG-13 15:53:00 to 03-AUG-13 15:53:00 (MST-7)
Location: GREELEY
Magnitude: 1.00 
Reported by: CoCoRaHS

Tornado in WASHINGTON, COLORADO
From 03-AUG-13 14:37:00 to 03-AUG-13 14:37:00 (MST-7)
Location: LAST CHANCE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tornado touched down briefly in an open field.  No damage was reported.

Tornado in LINCOLN, COLORADO
From 03-AUG-13 15:07:00 to 03-AUG-13 15:07:00 (MST-7)
Location: GENOA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tornado touched down briefly in an open field.  No damage was reported.

Tornado in WELD, COLORADO
From 03-AUG-13 15:29:00 to 03-AUG-13 15:29:00 (MST-7)
Location: JOHNSTOWN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tornado touched down briefly in an open field.  No damage was reported.

Thunderstorm Wind in WELD, COLORADO
From 03-AUG-13 16:03:00 to 03-AUG-13 16:03:00 (MST-7)
Location: EVANS
Magnitude: 50.00 EG
Reported by: Amateur Radio

Thunderstorm winds snapped large tree branches, up to 12 inches in diameter.

Flash Flood in ARAPAHOE, COLORADO
From 03-AUG-13 18:54:00 to 03-AUG-13 21:45:00 (MST-7)
Location: (BKF)BUCKLEY AIR FORCE BASE
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Road closures were set up in both directions on both Picadilly Road and Gun Club Road, just north of Buckley AFB.  A man had to be rescued when his car was trapped in flood waters at the intersection of 6th Ave. and Picadilly Road.  Flash Flooding was also observed at the junction of E-470 and I-70 with water running over the road.