Severe thunderstorms produced large hail, torrential rainfall and quarter size hail across parts of Larimer, Lincoln and Weld counties.  The combination of heavy rain and hail overwhelmed the drainage system in Evans, and produced widespread street flooding.  Nearly 2.4 inches of rain fell in less than 45 minutes. Greeley Public Works briefly closed the roadway near Centerplace and 47th Avenue due to high water.  In Weld County, straight-line winds tore the roof off a large outbuilding and caved in an exterior wall. Farm equipment inside the structure was damaged in addition to nearby crops.  According to Xcel Energy, about 5,000 customers were without power in the Greeley, Evans and LaSalle areas for nearly two hours.  Strong winds and large hail struck between Keenseburg and Roggen.  One farmstead reported their crops were completely flattened.  In addition, sixty-six head of cattle were injured and later euthanized.  Intense straight-line winds also uprooted trees and downed power lines in Lincoln County, near Punkin Center and along CO 71 north of Limon.

Thunderstorm Wind in LARIMER, COLORADO
From 10-AUG-17 14:05:00 to 10-AUG-17 14:05:00 (MST-7)
Location: LAPORTE
Magnitude: 56.00 MG
Reported by: Mesonet

Hail in WELD, COLORADO
From 10-AUG-17 15:40:00 to 10-AUG-17 15:40:00 (MST-7)
Location: KEENESBURG
Magnitude: 1.00 
Reported by: Emergency Manager

Strong winds and large hail accompanied a thunderstorm that struck between Keenseburg and Roggen.  One farmstead reported the crops were completely flattened in one field.  In addition, sixty-six head of cattle were injured and later euthanized.

Heavy Rain in WELD, COLORADO
From 10-AUG-17 15:38:00 to 10-AUG-17 15:38:00 (MST-7)
Location: LUCERNE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain forced brief road closures in Greeley due to standing water.  A trained spotter measured 2.38 inches of rain, which fell in less than 45 minutes.

Hail in ADAMS, COLORADO
From 10-AUG-17 14:05:00 to 10-AUG-17 14:05:00 (MST-7)
Location: FT CARSON
Magnitude: 0.88 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 10-AUG-17 14:05:00 to 10-AUG-17 14:05:00 (MST-7)
Location: DRAKES
Magnitude: 0.88 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 10-AUG-17 14:07:00 to 10-AUG-17 14:07:00 (MST-7)
Location: DRAKES
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 10-AUG-17 14:10:00 to 10-AUG-17 14:10:00 (MST-7)
Location: DRAKES
Magnitude: 0.88 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 10-AUG-17 14:10:00 to 10-AUG-17 14:10:00 (MST-7)
Location: DRAKES
Magnitude: 1.00 
Reported by: Public

Hail in LARIMER, COLORADO
From 10-AUG-17 14:11:00 to 10-AUG-17 14:11:00 (MST-7)
Location: DRAKES
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in LINCOLN, COLORADO
From 10-AUG-17 15:55:00 to 10-AUG-17 15:55:00 (MST-7)
Location: (LIC)LIMON ARPT
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in WELD, COLORADO
From 10-AUG-17 14:01:00 to 10-AUG-17 14:01:00 (MST-7)
Location: GARDEN CITY
Magnitude: 50.00 MG
Reported by: Trained Spotter

Thunderstorm Wind in WELD, COLORADO
From 10-AUG-17 15:19:00 to 10-AUG-17 15:19:00 (MST-7)
Location: KEENESBURG
Magnitude: 52.00 MG
Property damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in LINCOLN, COLORADO
From 10-AUG-17 17:19:00 to 10-AUG-17 17:19:00 (MST-7)
Location: PUNKIN CENTER
Magnitude: 52.00 MG
Reported by: Trained Spotter

Thunderstorm Wind in LINCOLN, COLORADO
From 10-AUG-17 17:20:00 to 10-AUG-17 17:20:00 (MST-7)
Location: PUNKIN CENTER
Magnitude: 61.00 EG
Reported by: Law Enforcement

Intense winds uprooted large trees and downed some power lines.

Thunderstorm Wind in WELD, COLORADO
From 10-AUG-17 15:45:00 to 10-AUG-17 15:45:00 (MST-7)
Location: ROGGEN
Magnitude: 70.00 EG
Reported by: Social Media

Intense straight-line winds tore the roof off a large outbuilding and caved in an exterior wall.  Farm equipment inside the structure was damaged.  Crop damage was also observed.