A stationary front laying west to east over eastern Washington and north Idaho on February 17th developed into surface low pressure and finally an Arctic cold front which sagged southward through the region during the day of February 18th. A fetch of Pacific moisture fed into the surface low and enhanced into a period of moderate intensity snow during the day of February 17th and into the morning of the 18th. Heavy snow accumulations resulted over the Cascades and northeast Washington mountains.  This storm also brought lesser but still significant accumulations of snow to the Spokane area and the Palouse region before very dry Arctic air descending out of Canada behind the front effectively ended precipitation over the region.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-FEB-18 04:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 8 miles north of Republic reported 5.3 inches of storm total new snow accumulation.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-FEB-18 04:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 4 miles north of Republic reported 6.1 inches of storm total new snow accumulation.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-FEB-18 04:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter 12 miles south of Wauconda reported 8.0 inches of new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer at Boundary Dam recorded 5.8 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer at Metaline Falls recorded 7.7 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Diamond Lake recorded 9.0 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Evans recorded 5.5 inches of storm total snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer at Stehekin recorded 8.5 inches of new snow accumulation from this storm.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer at Mazama recorded 9.4 inches of new snow accumulation from this storm.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 5 miles south of Peshastin recorded 10.0 inches of new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 8 miles south of Northport recorded 6.3 inches of storm total snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer near Winthrop recorded 8.1 inches of new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Clayton recorded 6.2 inches of storm total snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer in Leavenworth recorded 7.1 inches of new snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Ardenvoir recorded 5.4 inches of new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter near Loon Lake reported 8.0 inches of new snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer in Holden Village recorded 12.9 inches of new snow accumulation from this storm.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 7 miles northwest of Winthrop recorded 10.0 inches of new snow accumulation.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-FEB-18 04:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Boyds recorded 7.8 inches of new snow accumulation.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-FEB-18 04:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 8 miles northeast of Republic reported 5.5 inches of storm total new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The 49 North ski resort reported 23 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The Mount Spokane ski resort reported 11.0 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-FEB-18 03:00:00 to 18-FEB-18 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer at Boundary Dam recorded 5.8 inches of storm total snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-FEB-18 01:00:00 to 18-FEB-18 16:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer at Plain recorded 12.9 inches of new snow accumulation from this storm.