The storms that moved across northern Washington County caused severe agricultural damage. Wheat fields were significantly damaged and the young corn was stripped of all its leaves. Although no roads were completely washed out, there were multiple places where water ran across the roads and washed away the gravel and damaged the shoulders. One house at State Highway 61 and county road 57 had at least one broken window from the hail.   Most of the water and damage from these storms was between state highways 61 and 63, and between county roads 60 and 55.
In Weld County, several communities received hail damage and flooding due to severe thunderstorms:  Frederick, Firestone, Hudson, Keenesburg and Prospect Valley. Lightning struck an injection well northeast of Hudson, sparking a fire.  First responders worked this incident for several hours.  Weld County had several road closures due to flash flooding including Hudson, Keenesburg, Roggen and Prospect Valley.  Some of the road closures included:  county road 46 from between county roads 45 to 47, county road 63 from county roads 16 to 16.5.  Trained spotters measured storm total rainfall from 2.93 inches to 5.53 inches.

Hail in JEFFERSON, COLORADO
From 18-JUN-18 11:05:00 to 18-JUN-18 11:05:00 (MST-7)
Location: JEFFERSON CO ARPT
Magnitude: 2.00 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 16:58:00 to 18-JUN-18 16:58:00 (MST-7)
Location: BOULDER
Magnitude: 1.00 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 17:00:00 to 18-JUN-18 17:00:00 (MST-7)
Location: BOULDER
Magnitude: 1.00 
Reported by: Emergency Manager

Hail in BOULDER, COLORADO
From 18-JUN-18 17:04:00 to 18-JUN-18 17:04:00 (MST-7)
Location: BOULDER ARPT
Magnitude: 1.75 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 17:08:00 to 18-JUN-18 17:08:00 (MST-7)
Location: BOULDER
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 17:10:00 to 18-JUN-18 17:10:00 (MST-7)
Location: BOULDER
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 17:10:00 to 18-JUN-18 17:10:00 (MST-7)
Location: BOULDER ARPT
Magnitude: 1.75 
Reported by: Public

Hail in WELD, COLORADO
From 18-JUN-18 17:13:00 to 18-JUN-18 17:13:00 (MST-7)
Location: MEAD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 17:15:00 to 18-JUN-18 17:15:00 (MST-7)
Location: BOULDER ARPT
Magnitude: 1.75 
Reported by: Public

Hail in WELD, COLORADO
From 18-JUN-18 17:19:00 to 18-JUN-18 17:19:00 (MST-7)
Location: MEAD
Magnitude: 1.25 
Reported by: Social Media

Hail in ADAMS, COLORADO
From 18-JUN-18 17:30:00 to 18-JUN-18 17:30:00 (MST-7)
Location: FEDERAL HGT
Magnitude: 1.00 
Reported by: CoCoRaHS

Hail in WELD, COLORADO
From 18-JUN-18 17:32:00 to 18-JUN-18 17:32:00 (MST-7)
Location: PLATTEVILLE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 17:35:00 to 18-JUN-18 17:35:00 (MST-7)
Location: NIWOT
Magnitude: 1.00 
Reported by: Social Media

Hail in WELD, COLORADO
From 18-JUN-18 17:43:00 to 18-JUN-18 17:43:00 (MST-7)
Location: MEAD
Magnitude: 1.75 
Reported by: Social Media

Hail in WELD, COLORADO
From 18-JUN-18 17:48:00 to 18-JUN-18 17:48:00 (MST-7)
Location: FREDERICK
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 18-JUN-18 17:51:00 to 18-JUN-18 17:51:00 (MST-7)
Location: FREDERICK
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 18-JUN-18 17:51:00 to 18-JUN-18 17:51:00 (MST-7)
Location: FIRESTONE
Magnitude: 1.50 
Reported by: Public

Hail in WELD, COLORADO
From 18-JUN-18 17:55:00 to 18-JUN-18 17:55:00 (MST-7)
Location: FREDERICK
Magnitude: 1.75 
Reported by: NWS Employee

Hail in WELD, COLORADO
From 18-JUN-18 18:00:00 to 18-JUN-18 18:00:00 (MST-7)
Location: FREDERICK
Magnitude: 2.50 
Reported by: NWS Employee

Hail in WELD, COLORADO
From 18-JUN-18 18:11:00 to 18-JUN-18 18:11:00 (MST-7)
Location: GARDEN CITY
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 18-JUN-18 18:18:00 to 18-JUN-18 18:18:00 (MST-7)
Location: FIRESTONE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:20:00 to 18-JUN-18 18:20:00 (MST-7)
Location: MARSHALL
Magnitude: 1.00 
Reported by: NWS Employee

Hail in BOULDER, COLORADO
From 18-JUN-18 18:28:00 to 18-JUN-18 18:28:00 (MST-7)
Location: MARSHALL
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in WELD, COLORADO
From 18-JUN-18 18:30:00 to 18-JUN-18 18:30:00 (MST-7)
Location: FREDERICK
Magnitude: 1.50 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:31:00 to 18-JUN-18 18:31:00 (MST-7)
Location: SUPERIOR
Magnitude: 3.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:38:00 to 18-JUN-18 18:38:00 (MST-7)
Location: BOULDER ARPT
Magnitude: 1.75 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 18:39:00 to 18-JUN-18 18:39:00 (MST-7)
Location: LOUISVILLE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:40:00 to 18-JUN-18 18:40:00 (MST-7)
Location: LOUISVILLE
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:43:00 to 18-JUN-18 18:43:00 (MST-7)
Location: LOUISVILLE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:45:00 to 18-JUN-18 18:45:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.50 
Reported by: CoCoRaHS

Hail in BOULDER, COLORADO
From 18-JUN-18 18:45:00 to 18-JUN-18 18:45:00 (MST-7)
Location: LOUISVILLE
Magnitude: 1.00 
Reported by: NWS Employee

Hail in BOULDER, COLORADO
From 18-JUN-18 18:45:00 to 18-JUN-18 18:45:00 (MST-7)
Location: BOULDER ARPT
Magnitude: 2.00 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 18:46:00 to 18-JUN-18 18:46:00 (MST-7)
Location: LOUISVILLE
Magnitude: 2.00 
Reported by: Social Media

Hail in BOULDER, COLORADO
From 18-JUN-18 18:49:00 to 18-JUN-18 18:49:00 (MST-7)
Location: LOUISVILLE
Magnitude: 2.00 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 18:49:00 to 18-JUN-18 18:49:00 (MST-7)
Location: LOUISVILLE
Magnitude: 1.00 
Reported by: Public

Hail in BOULDER, COLORADO
From 18-JUN-18 18:52:00 to 18-JUN-18 18:52:00 (MST-7)
Location: LAFAYETTE
Magnitude: 2.50 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 18-JUN-18 18:57:00 to 18-JUN-18 18:57:00 (MST-7)
Location: LAFAYETTE
Magnitude: 1.50 
Reported by: Social Media

Hail in WELD, COLORADO
From 18-JUN-18 19:00:00 to 18-JUN-18 19:00:00 (MST-7)
Location: ERIE
Magnitude: 1.00 
Reported by: Social Media

Hail in BROOMFIELD, COLORADO
From 18-JUN-18 19:23:00 to 18-JUN-18 19:23:00 (MST-7)
Location: BROOMFIELD
Magnitude: 1.50 
Reported by: CoCoRaHS

Hail in JEFFERSON, COLORADO
From 18-JUN-18 19:23:00 to 18-JUN-18 19:23:00 (MST-7)
Location: JEFFERSON CO ARPT
Magnitude: 1.75 
Reported by: Storm Chaser

Hail in JEFFERSON, COLORADO
From 18-JUN-18 19:27:00 to 18-JUN-18 19:27:00 (MST-7)
Location: JEFFERSON CO ARPT
Magnitude: 1.00 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 18-JUN-18 19:30:00 to 18-JUN-18 19:30:00 (MST-7)
Location: FEDERAL HGT
Magnitude: 2.00 
Reported by: Amateur Radio

Hail in BROOMFIELD, COLORADO
From 18-JUN-18 19:31:00 to 18-JUN-18 19:31:00 (MST-7)
Location: BROOMFIELD
Magnitude: 1.00 
Reported by: NWS Employee

Hail in BROOMFIELD, COLORADO
From 18-JUN-18 19:34:00 to 18-JUN-18 19:34:00 (MST-7)
Location: BROOMFIELD
Magnitude: 1.50 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 18-JUN-18 19:35:00 to 18-JUN-18 19:35:00 (MST-7)
Location: FEDERAL HGT
Magnitude: 1.00 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 18-JUN-18 19:46:00 to 18-JUN-18 19:46:00 (MST-7)
Location: NORTHGLENN
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 18-JUN-18 19:47:00 to 18-JUN-18 19:47:00 (MST-7)
Location: NORTHGLENN
Magnitude: 1.75 
Reported by: Public

Hail in ADAMS, COLORADO
From 18-JUN-18 19:47:00 to 18-JUN-18 19:47:00 (MST-7)
Location: NORTHGLENN
Magnitude: 2.00 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 18-JUN-18 19:48:00 to 18-JUN-18 19:48:00 (MST-7)
Location: HENDERSON
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ADAMS, COLORADO
From 18-JUN-18 19:49:00 to 18-JUN-18 19:49:00 (MST-7)
Location: HENDERSON
Magnitude: 2.50 
Reported by: NWS Employee

Hail in ADAMS, COLORADO
From 18-JUN-18 20:05:00 to 18-JUN-18 20:05:00 (MST-7)
Location: BRIGHTON
Magnitude: 2.75 
Reported by: Social Media

Hail in WELD, COLORADO
From 18-JUN-18 20:21:00 to 18-JUN-18 20:21:00 (MST-7)
Location: LOCHBUIE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Hail in MORGAN, COLORADO
From 18-JUN-18 20:39:00 to 18-JUN-18 20:39:00 (MST-7)
Location: SNYDER
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large hail broke several windows.

Hail in WASHINGTON, COLORADO
From 18-JUN-18 20:57:00 to 18-JUN-18 20:57:00 (MST-7)
Location: MESSEX
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in MORGAN, COLORADO
From 18-JUN-18 21:13:00 to 18-JUN-18 21:13:00 (MST-7)
Location: WELDONA
Magnitude: 1.00 
Reported by: Trained Spotter

Heavy rain totaling 1.5 inches was also observed.

Hail in WASHINGTON, COLORADO
From 18-JUN-18 21:33:00 to 18-JUN-18 21:33:00 (MST-7)
Location: MESSEX
Magnitude: 1.75 
Reported by: Trained Spotter

Hail, two inches in depth, covered the roadways.

Hail in WASHINGTON, COLORADO
From 18-JUN-18 21:54:00 to 18-JUN-18 21:54:00 (MST-7)
Location: BURDETT
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 19-JUN-18 11:18:00 to 19-JUN-18 11:18:00 (MST-7)
Location: NIWOT
Magnitude: 1.00 
Reported by: CoCoRaHS

Thunderstorm Wind in MORGAN, COLORADO
From 18-JUN-18 20:45:00 to 18-JUN-18 20:45:00 (MST-7)
Location: BRUSH MUNI ARPT
Magnitude: 52.00 EG
Reported by: CoCoRaHS

An intense thunderstorm wind gusts broke a large branch, 6 inches in diameter, off a tree.
The branch crash onto nearby vehicles and broke the windows.

Thunderstorm Wind in MORGAN, COLORADO
From 18-JUN-18 20:15:00 to 18-JUN-18 20:15:00 (MST-7)
Location: FT MORGAN ARPT
Magnitude: 62.00 MG
Reported by: AWOS

Thunderstorm Wind in WASHINGTON, COLORADO
From 18-JUN-18 21:33:00 to 18-JUN-18 21:33:00 (MST-7)
Location: MESSEX
Magnitude: 52.00 MG
Reported by: Trained Spotter

Flash Flood in WELD, COLORADO
From 18-JUN-18 22:35:00 to 19-JUN-18 05:00:00 (MST-7)
Location: KEENESBURG
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several roads were damaged.  The frontage road at Interstate 76 and Weld County Road 53 which was inundated by floodwaters and completely washed.  County roads 16 and 63, and county road 49 and State Highway 52 were partially flooded.