A well directed atmospheric river of Pacific moisture enhanced into widespread snow and freezing rain over eastern Washington during January 17th and 18th. Heavy snow impacted the mountains and valleys north and west of the Columbia Basin. In the Columbia Basin a cold arctic air mass trapped near the surface was over ridden by a warm front which allowed the ensuing rain to freeze on contact promoting heavy ice accumulations on roads and other surfaces effectively paralyzing travel in and around the Columbia Basin on the 17th and through the morning of the 18th. Washington State Police responded to over 100 vehicle accidents during this storm and over 50 school districts were closed or delayed opening on January 18th.  On the northern margins of the basin and in the southern valleys of the Cascades and northern mountains a wintry mix of snow, sleet and freezing rain was noted.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 08:00:00 to 18-JAN-17 20:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer at Stehekin measured 10 inches of new snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 08:00:00 to 18-JAN-17 20:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Holden Village measured 11.5 inches of new snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 08:00:00 to 18-JAN-17 20:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Seven inches of new snow accumulation was recorded near Leavenworth. Some sleet and freezing rain was also noted during the event.

Winter Storm in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Precipitation initially began as freezing rain leaving 0.12 inches of ice accumulation. Then the freezing rain turned to snow during the afternoon with 6 inches of snow accumulation overnight.

Winter Storm in WENATCHEE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A mix of snow and sleet and and a thin layer of ice from freezing rain was reported at East Wenatchee.

Winter Storm in WENATCHEE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Several reports from social media indicated one tenth to two tenths of and inch of ice accumulation in and around the Wenatchee area and near Chelan. Two to locally 4 inches of snow accumulation  was also noted.

Winter Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 17-JAN-17 08:00:00 to 18-JAN-17 09:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Precipitation began as freezing rain with an unspecified layer of ice accumulation during the day of the 17th. The freezing rain turned to snow with 5 inches of accumulation overnight into the morning of the 18th.

Winter Storm in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Seven inches of snow mixed with sleet was reported in Leavenworth.

Winter Storm in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 17:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Freezing rain deposited a tenth of an inch of ice accumulation followed by two inches of snow accumulation on top of the ice near Tum Tum.

Ice Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 17-JAN-17 09:00:00 to 18-JAN-17 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An estimated two tenths of an inch of ice accumulation was noted at Hartline.

Heavy Snow in OKANOGAN VALLEY, WASHINGTON
From 17-JAN-17 12:00:00 to 18-JAN-17 09:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

An estimated 5 to 6 inches of snow was reported from Omak.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer measured 5.1 inches of new snow at Wauconda.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer measured 5.6 inches of snow near Malo.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer measured 4.5 inches of snow near Republic.

Heavy Snow in OKANOGAN VALLEY, WASHINGTON
From 17-JAN-17 15:00:00 to 18-JAN-17 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer measured 5 inches of new snow near Okanogan.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A person near Gifford reported an estimated 8 inches of new snow accumulation.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 11:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Seven inches of new snow was reported 12 miles southwest of Monitor.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 17-JAN-17 11:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Seven inches of new snow was reported 12 miles southwest of Monitor.

Winter Storm in WENATCHEE AREA, WASHINGTON
From 17-JAN-17 08:00:00 to 18-JAN-17 09:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A 4 inch accumulation of snow and sleet was reported from East Wenatchee. Freezing rain was also noted during the storm.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 14:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Four inches of new snow accumulation was reported from Chewelah.

Winter Storm in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 12:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

An observer in Springdale reported 5 inches of new snow accumulation which turned to a wintry mix on the morning of the 18th.

Winter Storm in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Six inches of snow mixed with freezing rain was reported from near Rice.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

An observer near Colville reported 6 inches of heavy wet snow.

Winter Storm in SPOKANE AREA, WASHINGTON
From 17-JAN-17 17:00:00 to 18-JAN-17 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Freezing rain produced around a tenth of an inch of ice accumulation and then freezing rain turned to snow overnight with 3 inches of snow accumulation on top of the ice in northwest Spokane.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Four inches of new snow was reported near Northport.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 10:00:00 to 18-JAN-17 13:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The 49 North Ski Resort measured 13 inches of new snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Boundary Dam near Metaline Falls reported 4.6 inches of new snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 14:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Six inches of new snow was reported from Addy.

Winter Storm in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 13:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Five inches of new snow was reported which then turned to sleet before ending.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 17-JAN-17 14:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Six inches of new snow was reported near Kettle Falls.

Winter Storm in OKANOGAN VALLEY, WASHINGTON
From 17-JAN-17 12:00:00 to 18-JAN-17 13:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter near Okanogan reported 5.3 inches of new snow in addition to one tenth of an inch of ice from freezing rain.

Heavy Snow in OKANOGAN VALLEY, WASHINGTON
From 17-JAN-17 12:00:00 to 18-JAN-17 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter reported 6 inches of new snow at Malott.

Ice Storm in WENATCHEE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Three inches of sleet was reported by a member of the public in Wenatchee.

Ice Storm in WATERVILLE PLATEAU, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Freezing rain deposited one half inch of ice accumulation at Waterville.

Ice Storm in MOSES LAKE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Freezing rain deposited a quarter inch of ice accumulation at Moses Lake.

Ice Storm in MOSES LAKE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Freezing rain deposited a half inch of ice accumulation at Soap Lake.

Ice Storm in MOSES LAKE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Freezing rain deposited a six tenths of an inch of ice accumulation at Ephrata.

Ice Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Freezing rain deposited two tenths of an inch of ice accumulation at Hartline.

Ice Storm in UPPER COLUMBIA BASIN, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Freezing rain deposited a quarter of an inch of ice accumulation at Coulee City. Two inches of sleet was also noted in addition to the ice.

Ice Storm in MOSES LAKE AREA, WASHINGTON
From 17-JAN-17 07:00:00 to 18-JAN-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

One inch of sleet and then freezing rain causing a quarter inch of ice accumulation was noted at Quincy.

Ice Storm in SPOKANE AREA, WASHINGTON
From 17-JAN-17 17:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Freezing rain deposited a quarter inch of ice accumulation in northwest Spokane during the night of January 17th.

Ice Storm in SPOKANE AREA, WASHINGTON
From 17-JAN-17 17:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Two tenths of an inch of freezing rain was measured at the NWS office in Spokane.

Ice Storm in SPOKANE AREA, WASHINGTON
From 17-JAN-17 17:00:00 to 18-JAN-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Three tenths of an inch of ice accumulation from freezing rain was recorded 5 miles south of Spokane.