A stationary trough of low pressure along the Pacific Northwest Coastline resulted in moist, unstable, southwesterly flow over the Inland Northwest.  A shortwave embedded within the flow, triggered thunderstorms during the afternoon hours of August 25, 2013.  The storms originated in the Lower Columbia Basin and quickly moved through the Basin and into the northern mountain regions of Washington and the Idaho Panhandle.  A strong squall line emerged from this activity which created damaging winds resulting in a dust storm and numerous downed trees and power lines.  There was one fatality and one injury at campground from a large tree falling on a tent.  Several other areas experienced property damage.

Thunderstorm Wind in PEND OREILLE, WASHINGTON
From 25-AUG-13 19:58:00 to 25-AUG-13 21:35:00 (PST-8)
Location: CAMDEN
Magnitude: 52.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous trees and power lines were downed throughout the county resulting in power outages and some damage to structures.  Power outages were reported in Diamond Lake and Tiger but it was assumed many more power outages occurred in other communities.  There was one fatality and one injury when a 200 foot tall tree uprooted and fell on a tent at the Stagger Inn Campground in the Kaniksu National Forest.

Thunderstorm Wind in SPOKANE, WASHINGTON
From 25-AUG-13 18:45:00 to 25-AUG-13 20:10:00 (PST-8)
Location: AMBER
Magnitude: 54.00 MG
Property damage: 80.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The Spokane NWS clocked a wind gust of 62 mph on the RSOIS.  Numerous trees, some large, were downed in Nine Mile Falls area, especially along West Charles Road.  Some trees were uprooted and other were snapped halfway up the trunk.  Trees fell on a combination of roofs, outbuildings, fences, and power lines resulting in multiple power outages.  A large tree was uprooted along Highway 2 in the Deep Creek community.  A large tree fell on a power line in Chattaroy leading to 178 power outages.

Thunderstorm Wind in FERRY, WASHINGTON
From 25-AUG-13 19:40:00 to 25-AUG-13 21:35:00 (PST-8)
Location: KELLER
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Utility Company

A large tree was downed and fell across power lines in Republic resulting in numerous power outages.

Thunderstorm Wind in ADAMS, WASHINGTON
From 25-AUG-13 17:45:00 to 25-AUG-13 18:35:00 (PST-8)
Location: OTHELLO ARPT
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Utility Company

Several trees and power lines were knocked down from strong thunderstorm winds across east and southeastern sections of Othello.  Reports from the utility company included:  power lines down from a fallen tree two miles southeast of Othello, a downed power pole six miles southeast of Othello, and another power pole downed six miles southeast of Warden.  A newspaper also reported at least eight large trees blown down in the town of Lind.  The downed trees resulted in damage to fences and power lines.

Dust Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 25-AUG-13 18:20:00 to 25-AUG-13 18:35:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A thunderstorm squall resulted in a dust storm across the Columbia Basin.  A trained spotter in Ritzville reported the dust storm and shared pictures which illustrated a wall of dust a couple hundred feet tall coupled with low visibility.

Thunderstorm Wind in LINCOLN, WASHINGTON
From 25-AUG-13 18:55:00 to 25-AUG-13 19:55:00 (PST-8)
Location: DOWNS
Magnitude: 56.00 MG
Property damage: 80.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

In the town of Harrington, two large trees were split.  One tree was located on the golf course and second on 5th and Sherlock.  No damage was noted to the property.  Widespread two to four inch branches were scattered on ground around town.  The Odessa Agrimet Sensor clocked a peak wind gust of 57 miles per hour.  Several trees were downed in Davenport but no property damage was reported.  One tree did land on a powerline leading to 29 power outages.  A large tree was blown down at the Sherman Cemetary.  A greenhouse was destroyed on a property located seven miles north of Reardan.  The Spring Canyon RAWS located three miles southeast of Coulee Dam clocked a wind gust of 65 miles per hour.  The storm also knocked down multiple trees at the Lakeview Terrace mobile home park.  Two mobile homes were damaged.

Thunderstorm Wind in OKANOGAN, WASHINGTON
From 25-AUG-13 19:28:00 to 25-AUG-13 19:45:00 (PST-8)
Location: COULEE DAM
Magnitude: 56.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous trees and power lines were downed within and around Coulee City.  Downed trees blocked roads, damaged vehicles, boat trailers, street signs, and homes.  A large tree fell across State Route 155 closing the highway for over three hours.  The roof was partially torn off at the Coulee Dam Casino.  Several signs were also damaged at the casino.  Due to the roof damage, moderate rains trailing behind the wind resulted in water damage to portions of the casino and offices.  The Spring Canyon RAWS located three miles southeast of Coulee Dam clocked a wind gust of 65 miles per hour.

Thunderstorm Wind in STEVENS, WASHINGTON
From 25-AUG-13 19:30:00 to 25-AUG-13 21:35:00 (PST-8)
Location: WELLPINIT
Magnitude: 52.00 MG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A strong gust front associated with a thunderstorm squall resulted in numerous trees and power lines downed throughout the county.  Over 400 power outages were reported within the communities of Ford, Fruitland, Clayton, and Colville.  The Midnite Mine RAWS located six miles northwest of Wellpinit clocked a wind gust of 57 mph.  A DOT sensor located one mile west of Suncrest clocked a wind gust of 55 mph.  Both sensors experience some degree of sheltering.  One tree did fall on a house but the exact location is unknown.

Thunderstorm Wind in GRANT, WASHINGTON
From 25-AUG-13 18:10:00 to 25-AUG-13 19:35:00 (PST-8)
Location: MOSES LAKE
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Utility Company

Roughly fifty customers in the Mae Valley subdivision of Moses Lake lost power when strong thunderstorm winds damaged five different power poles holding transmission lines.
As the gust front moved into northern sections of Grant County, law enforcement reported numerous trees and power poles downed in and around Grand Coulee.  Overall, 6500 customers loss power across Grant County during the storm.