A negatively tilted shortwave trough of lower pressure interacted with some surface based instability of near 1,000 J/KG in northern Oregon to spawn a squall line that traversed northward across eastern Washington.  Strong winds mixed down to the surface along the squall line to created widespread damaging wind gusts.  The squall line could be classified as a Haboob as the strongest winds occurred out ahead of the thunderstorms that kicked up a massive dust cloud.  The Haboob hit the Moses Lake area and Upper Columbia Basin the hardest with widespread wind damage reported.  The dust cloud resulted in a rapid reduction in visibility to near zero in places.  Impacts from the Haboob were felt as far north as Coulee City eastward into Spokane and into Deer Park.  Strong damaging winds and reduced visibility due to dust were reported across these areas as well.

Thunderstorm Wind in WHITMAN, WASHINGTON
From 15-SEP-13 18:55:00 to 15-SEP-13 19:05:00 (PST-8)
Location: LA CROSSE
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm Wind in WHITMAN, WASHINGTON
From 15-SEP-13 20:25:00 to 15-SEP-13 21:00:00 (PST-8)
Location: ST JOHN
Magnitude: 50.00 EG
Crop damage: 0.00K
Reported by: Utility Company

A tree fell into some power lines knocking out power to three customers.

Thunderstorm Wind in GRANT, WASHINGTON
From 15-SEP-13 21:00:00 to 15-SEP-13 21:40:00 (PST-8)
Location: RUFF
Magnitude: 50.00 EG
Crop damage: 0.00K
Reported by: Public

Shop doors blown off and power poles downed across Wheeler Road.

Thunderstorm Wind in LINCOLN, WASHINGTON
From 15-SEP-13 20:00:00 to 15-SEP-13 20:15:00 (PST-8)
Location: MILES
Magnitude: 50.00 EG
Crop damage: 0.00K
Reported by: Public

Numerous trees either toppled over or tops snapped off at the Fort Spokane Campground.

Thunderstorm Wind in GRANT, WASHINGTON
From 15-SEP-13 18:35:00 to 15-SEP-13 19:20:00 (PST-8)
Location: CORFU
Magnitude: 50.00 MG
Reported by: Trained Spotter

Winds in Warden were sustained 30 to 35 miles per hour with gusts up to 58 miles per hour as the gust from moved through.  Numerous trees downed and widespread power outages across the Moses Lake area.  Some trees fell on houses and on vehicles.  An outbuilding was destroyed and a fence was damaged by flying debris.  At least six power poles were snapped off near Soap Lake.  Schools across the Moses Lake area were closed the following day due to impacts from the storm.

Thunderstorm Wind in SPOKANE, WASHINGTON
From 15-SEP-13 19:50:00 to 15-SEP-13 20:40:00 (PST-8)
Location: ESPANOLA
Magnitude: 52.00 MG
Reported by: Broadcast Media

Numerous reports of trees falling onto power lines resulting in over a thousand customers losing power.  Damage was reported in Cheney, to Spokane, to Mead and in Deer Park.  A large tree toppled over at 21st Street and High Drive in Spokane on South Hill.  Other trees reported down or snapped off resulting in damage to homes and/or vehicles.  Many tents at the Spokane County Interstate Fair were damaged or flipped over due to the strong winds from the gust front.

Thunderstorm Wind in LINCOLN, WASHINGTON
From 15-SEP-13 20:25:00 to 15-SEP-13 20:35:00 (PST-8)
Location: ALMIRA
Magnitude: 51.00 EG
Reported by: Trained Spotter

Large tree limb estimated at ten to twelve inches in diameter snapped off.  Numerous other three to four inch diameter limbs down across the area.  A metal roof was blown off of an enclosure.

Dust Storm in MOSES LAKE AREA, WASHINGTON
From 15-SEP-13 18:15:00 to 15-SEP-13 18:40:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Visibility was reduced to 50 feet in Warden.

Dust Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 15-SEP-13 18:35:00 to 15-SEP-13 18:50:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large dust cloud engulfed the area reducing visibility to near zero.

Dust Storm in SPOKANE AREA, WASHINGTON
From 15-SEP-13 20:00:00 to 15-SEP-13 20:30:00 (PST-8)
Crop damage: 0.00K
Reported by: Law Enforcement

Visibilities down to below one quarter of a mile in North Spokane due to blowing dust.  One indirect injury reported as a pedestrian was struck by a vehicle due to the poor visibility.

Thunderstorm Wind in ADAMS, WASHINGTON
From 15-SEP-13 18:23:00 to 15-SEP-13 18:35:00 (PST-8)
Location: OTHELLO TANGO ARPT
Magnitude: 50.00 MG
Reported by: Trained Spotter

Numerous trees and power lines downed in Othello.  Trees toppled onto homes and fences.  An estimate of forty power poles snapped off.  Schools across the Othello area were closed the following day due to impacts from the storm.

Thunderstorm Wind in LINCOLN, WASHINGTON
From 15-SEP-13 19:10:00 to 15-SEP-13 19:20:00 (PST-8)
Location: ODESSA
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in ADAMS, WASHINGTON
From 15-SEP-13 19:00:00 to 15-SEP-13 19:20:00 (PST-8)
Location: PAHA
Magnitude: 51.00 EG
Reported by: Utility Company

Numerous trees and power lines downed in Ritzville.  Some trees fell on houses and on outdoor equipment.

Thunderstorm Wind in LINCOLN, WASHINGTON
From 15-SEP-13 19:20:00 to 15-SEP-13 19:50:00 (PST-8)
Location: DOWNS
Magnitude: 51.00 EG
Reported by: Public

A roof was blown off of a barn approximately eight miles southeast of Harrington.

Thunderstorm Wind in ADAMS, WASHINGTON
From 15-SEP-13 18:40:00 to 15-SEP-13 18:50:00 (PST-8)
Location: WASHTUCNA
Magnitude: 52.00 EG
Reported by: Utility Company

Strong winds from a thunderstorm destroyed a combine shed, uprooted 5 trees and blew off a roof of a barn.  Winds also knocked out power to 40 customers.