A negatively tilted upper trough and associated cold front swung across the 4 Corners region and incorporated monsoonal moisture to produce strong thunderstorms with large hail and heavy rainfall across southwest Colorado. The runoff from this rainfall caused flash flooding in many areas, including locations around Durango.  Hail damage to personal property in La Plata County was estimated to be at least two million dollars.

Flash Flood in DOLORES, COLORADO
From 22-SEP-13 16:25:00 to 23-SEP-13 19:00:00 (MST-7)
Location: DOVE CREEK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Coal Bed Creek was out of its banks.  Mud and debris also flowed underneath Highway 491 through a sixteen foot diameter culvert that was 3/4 full.

Hail in LA PLATA, COLORADO
From 22-SEP-13 12:15:00 to 22-SEP-13 12:29:00 (MST-7)
Location: KLINE
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Hail up to the size of hen eggs and strong winds caused considerable damage to residences and property near Marvel.

Hail in MONTROSE, COLORADO
From 22-SEP-13 12:20:00 to 22-SEP-13 12:30:00 (MST-7)
Location: BEDROCK
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter sized hail was reported on Highway 90 east of Bedrock.

Hail in DOLORES, COLORADO
From 22-SEP-13 12:30:00 to 22-SEP-13 12:40:00 (MST-7)
Location: DOVE CREEK
Magnitude: 1.50 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Ping pong ball sized hail was observed at intersection of Highway 141 and County Road E.

Hail in LA PLATA, COLORADO
From 22-SEP-13 12:30:00 to 22-SEP-13 12:40:00 (MST-7)
Location: BREEN
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail up to the size of hen eggs was reported.

Hail in DOLORES, COLORADO
From 22-SEP-13 13:14:00 to 22-SEP-13 13:30:00 (MST-7)
Location: DOVE CREEK
Magnitude: 1.50 
Property damage: 20.00K
Crop damage: 10.00K
Reported by: Broadcast Media

Ping pong ball sized hail was reported.

Flash Flood in LA PLATA, COLORADO
From 22-SEP-13 13:22:00 to 22-SEP-13 19:00:00 (MST-7)
Location: DURANGO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flash floods occurred along Highway 550, several county roads and through much of the Durango city limits. The heaviest flows were reported just north of Durango where Highway 550 was closed for several hours. Vehicles were trapped in the flow over the highway and several rescues were initiated.

Hail in LA PLATA, COLORADO
From 22-SEP-13 13:23:00 to 22-SEP-13 13:35:00 (MST-7)
Location: DURANGO
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Half dollar sized hail was reported in the town of Durango.

Hail in LA PLATA, COLORADO
From 22-SEP-13 13:30:00 to 22-SEP-13 13:40:00 (MST-7)
Location: BREEN
Magnitude: 2.00 
Property damage: 0.00K
Reported by: Trained Spotter

Hail up to two inches in diameter pummeled the area.

Hail in LA PLATA, COLORADO
From 22-SEP-13 12:51:00 to 22-SEP-13 12:59:00 (MST-7)
Location: REDMESA
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Ping pong ball sized hail was observed, along with strong winds which stripped leaves and branches from trees.

Thunderstorm Wind in LA PLATA, COLORADO
From 22-SEP-13 13:38:00 to 22-SEP-13 13:45:00 (MST-7)
Location: (DRO)DURANGO/LAPLATA
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Strong thunderstorm outflow winds were measured at the Durango La Plata County Airport.

Thunderstorm Wind in LA PLATA, COLORADO
From 22-SEP-13 12:51:00 to 22-SEP-13 12:59:00 (MST-7)
Location: REDMESA
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Ping pong sized hail also reported with the winds which stripped leaves and small branches off the trees.

Flash Flood in LA PLATA, COLORADO
From 22-SEP-13 13:45:00 to 22-SEP-13 20:00:00 (MST-7)
Location: TRIMBLE
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Emergency Manager

County Roads 240 and 247 were over-topped by fast moving water up to two feet deep.  Considerable damage occurred to County Road 240.

Hail in LA PLATA, COLORADO
From 22-SEP-13 13:50:00 to 22-SEP-13 13:59:00 (MST-7)
Location: BAYFIELD
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy Rain in LA PLATA, COLORADO
From 22-SEP-13 15:36:00 to 22-SEP-13 19:00:00 (MST-7)
Location: BAYFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dry Creek overflowed in a few spots and one local business had flood water that got inside of the building.

Hail in LA PLATA, COLORADO
From 22-SEP-13 14:20:00 to 22-SEP-13 14:30:00 (MST-7)
Location: BAYFIELD
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tennis ball sized hail was reported at 3rd and 13th streets in Durango.

Hail in ARCHULETA, COLORADO
From 22-SEP-13 14:10:00 to 22-SEP-13 14:20:00 (MST-7)
Location: ARBOLES
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Rain in LA PLATA, COLORADO
From 22-SEP-13 13:50:00 to 22-SEP-13 14:15:00 (MST-7)
Location: BAYFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A burst of heavy rainfall resulted in standing water of 4 to 6 inches in depth that covered the front and back yard of a residence.

Heavy Rain in MESA, COLORADO
From 22-SEP-13 15:05:00 to 22-SEP-13 17:15:00 (MST-7)
Location: CAMEO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A Skywarn spotter reported a couple of inches of water running over the road along Interstate 70 between mile markers 42 and 44 near Palisade due to heavy rainfall.

Heavy Rain in MESA, COLORADO
From 22-SEP-13 16:10:00 to 22-SEP-13 18:00:00 (MST-7)
Location: DURHAM
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rainfall resulted in minor flooding in an arroyo running behind Wal-Mart and Gold's Gym off of Highway 50.  Additionally, the parking lot behind Gold's Gym had standing water up to six inches deep.