A negatively tilted trough moved through western Colorado on the morning and afternoon of Saturday, June 6th, causing a widespread severe weather event that would become the first derecho to impact the Western Slope in well over a decade. Severe storms produced wind gusts upwards of 60 to 80 mph on average with some gusts topping 80 to 100 mph in some areas due to strong downburst winds. There were multiple reports of uprooted trees, downed power lines, at least one roof was torn off with others damaged, and several houses/cabins and vehicles were damaged by falling trees and/or large hail. Very heavy rain also fell which led to flash flooding in some areas.

Thunderstorm Wind in RIO BLANCO, COLORADO
From 06-JUN-20 11:15:00 to 06-JUN-20 11:25:00 (MST-7)
Location: RANGELY
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A peak wind gust of 58 mph was measured by the Dragon Road automated weather station.

Thunderstorm Wind in MESA, COLORADO
From 06-JUN-20 11:15:00 to 06-JUN-20 11:25:00 (MST-7)
Location: SKYWAY
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A National Weather Service employee measured a peak wind gust of 60 mph.

Thunderstorm Wind in RIO BLANCO, COLORADO
From 06-JUN-20 12:02:00 to 06-JUN-20 12:12:00 (MST-7)
Location: MEEKER ARPT
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A peak wind gust of 69 mph was measured by the automated weather station at the Meeker Coulter Field Airport.

Thunderstorm Wind in MESA, COLORADO
From 06-JUN-20 12:46:00 to 06-JUN-20 12:56:00 (MST-7)
Location: DE BEQUE
Magnitude: 86.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A peak wind gust of 99 mph was measured by the Great Divide automated weather station.

Thunderstorm Wind in RIO BLANCO, COLORADO
From 06-JUN-20 12:57:00 to 06-JUN-20 13:07:00 (MST-7)
Location: BUFORD
Magnitude: 75.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A peak wind gust of 86 mph was measured by the Dead Horse automated weather station.

Hail in MOFFAT, COLORADO
From 06-JUN-20 13:55:00 to 06-JUN-20 14:05:00 (MST-7)
Location: BLUE MTN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm produced large hail estimated to be the size of quarters east of Blue Mountain.

Hail in MONTEZUMA, COLORADO
From 06-JUN-20 09:50:00 to 06-JUN-20 10:00:00 (MST-7)
Location: DOLORES
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm produced large hail measured to be the size of quarters west-northwest of Dolores.

Thunderstorm Wind in GARFIELD, COLORADO
From 06-JUN-20 11:14:00 to 06-JUN-20 11:14:00 (MST-7)
Location: DOUGLAS PASS
Magnitude: 92.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A peak wind gust of 106 mph was measured by the Douglas Pass automated weather station, maintained by the Colorado Department of Transportation.

Thunderstorm Wind in MOFFAT, COLORADO
From 06-JUN-20 12:28:00 to 06-JUN-20 12:38:00 (MST-7)
Location: HIAWATHA CAMP
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A peak wind gust of 66 mph was measured by an automated weather station west-southwest of Hiawatha.

Thunderstorm Wind in DELTA, COLORADO
From 06-JUN-20 10:59:00 to 06-JUN-20 10:59:00 (MST-7)
Location: GRAND MESA
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts estimated to be in the 70 to 75 mph range uprooted some very large trees and caused damage to cabins and vehicles.

Thunderstorm Wind in ROUTT, COLORADO
From 06-JUN-20 12:49:00 to 06-JUN-20 12:49:00 (MST-7)
Location: HAYDEN
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts estimated to be in the 70 to 75 mph range uprooted or snapped some trees and blew the roof off of a house.

Thunderstorm Wind in PITKIN, COLORADO
From 06-JUN-20 13:09:00 to 06-JUN-20 13:09:00 (MST-7)
Location: SNOWMASS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Wind gusts estimated to be in the 60 to 65 mph range knocked over a large tree which blocked traffic in both directions on Emma Road near Mile Marker 3 on Colorado Highway 82.

Debris Flow in SAN JUAN, COLORADO
From 06-JUN-20 19:00:00 to 06-JUN-20 19:00:00 (MST-7)
Location: ELK PARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rain brought down a massive amount of debris from the Elk Creek drainage which jammed the Durango and Silverton Narrow Gauge railroad. The debris washed out over 40 feet of the tracks. CoCoRAHS reports from Silverton reported over an inch of rain having fallen from storms.

Thunderstorm Wind in MESA, COLORADO
From 06-JUN-20 11:15:00 to 06-JUN-20 11:15:00 (MST-7)
Location: SKYWAY
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts estimated to be in the 70 to 75 mph range uprooted large trees near Alexander Lake Lodge on the Grand Mesa.

Thunderstorm Wind in MOFFAT, COLORADO
From 06-JUN-20 12:30:00 to 06-JUN-20 12:30:00 (MST-7)
Location: CRAIG
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Wind gusts estimated to be in the 70 to 75 mph range caused significant roof damage to a house in Craig, Colorado.

Debris Flow in SAN MIGUEL, COLORADO
From 06-JUN-20 19:00:00 to 06-JUN-20 19:00:00 (MST-7)
Location: TELLURIDE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Debris left over from the 2019 avalanches became dislodged by heavy rain in the Marshall Creek Basin. A large amount of trees, wood, and other debris from old mining structures travelled down the drainage until it reached the culvert near CR K-69, near the Idarado mine. The water and debris overwhelmed the drainage and began flowing across the roadway. The downstream portion of the roadway began to scour with water and eroded the embankment along the southern shoulder. The road was closed for a few hours.

Thunderstorm Wind in MOFFAT, COLORADO
From 06-JUN-20 12:31:00 to 06-JUN-20 12:31:00 (MST-7)
Location: CRAIG
Magnitude: 78.00 EG
Property damage: 300.00K
Crop damage: 0.00K
Reported by: COOP Observer

Several homes on Dunn Drive in Craig, CO had severe damage. One home suffered damage to three sections of metal roofing. Also, the SW corner of a large pole barn lost many roof panels. Another house to the west lost 50% of its roof.  A separate 2 car garage at the residence also lost the SW corner of the roof. Another home had part of its attached garage roof blown off when the south facing garage doors were blown in.  A shed was also destroyed on this property. Another home, just to the south, also lost its roof. Finally, another home on the same road almost lost the entire metal roof off their single wide trailer.

Thunderstorm Wind in MESA, COLORADO
From 06-JUN-20 10:53:00 to 06-JUN-20 11:03:00 (MST-7)
Location: MACK
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter 5 miles northwest of Mack measured a peak wind gust of 69 mph.

Thunderstorm Wind in MESA, COLORADO
From 06-JUN-20 11:15:00 to 06-JUN-20 11:25:00 (MST-7)
Location: DURHAM
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A National Weather Service employee estimated a peak wind gust of 60 mph.

Thunderstorm Wind in GARFIELD, COLORADO
From 06-JUN-20 11:48:00 to 06-JUN-20 11:58:00 (MST-7)
Location: (1V1)RIFLE ARPT
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A peak wind gust of 63 mph was measured by the automated weather station at the Rifle Garfield County Airport.