Snow in forecast today, followed by blast of cold
The first significant snowstorm of the season was forecast across the Inland Northwest today and Sunday, to be followed by a new shot of arctic cold.
Up to 3 inches of snow is possible in Spokane by nightfall today. Less than an additional inch is expected tonight, according to the National Weather Service in Spokane.
Coeur d’Alene could see 2 to 4 inches today and another 2 to 4 inches tonight.
A winter storm warning was posted Friday afternoon for North Idaho, the Palouse, north Spokane County, Stevens County, Pend Oreille County, the northeast Blue Mountains and Camas Prairie southeast of Lewiston.
The warning remains in effect until 4 p.m. on Sunday.
Some locations in the warning area may see 6 to 10 inches of snow in the valleys and 9 to 15 inches in the mountains.
Forecasters said they expected an area of low pressure to migrate from the coast of British Columbia southeastward into North Idaho today. The heaviest snow should fall in the areas closest to that.
In Spokane, a winter weather advisory was in effect for lighter amounts of snow because the low is predicted to pass to the east of the Lilac City. The advisory is set to expire at 4 a.m. on Sunday.
Areas to the southwest of Spokane in the Columbia Basin may see rain by midday today.
Travel across mountain passes, especially in the Cascades, is expected to be treacherous.
Nine to 13 inches of snow may fall over the Cascades today, followed by another 6 to 10 inches tonight at Snoqualmie Pass on Interstate 90.
Lookout Pass on I-90 in North Idaho could see 10 to 18 inches of snow.
The snowstorm was expected to arrive in Spokane about 4 a.m. today.
Random snow showers are possible across the region through Monday.
Computer forecast models on Friday suggested a second storm front may bring 1 to 3 inches of snow to the deep Columbia Basin and east slopes of the Cascades on Sunday night and Monday, which would continue to make Washington cross-state travel difficult.
In addition to potentially heavy snow, the storm is going to bring breezy southwest winds today followed by stiff northeast winds Sunday night and Monday.
Cold arctic air is expected to be drawn southward by the departing snowstorm on Sunday and Monday. Snow on the ground will allow nighttime temperatures to drop quickly.
Windy conditions could cause drifting in some areas such as the Rathdrum Prairie, Purcell Trench and the Palouse. Wind chills on exposed skin could reach dangerous levels.
Highs will drop to 22 in Spokane on Monday and 12 degrees on Tuesday. Overnight lows will be in the teens and single digits. Spokane could see lows of 3 degrees on Monday night and 5 degrees on Tuesday night. Temperatures start to moderate on Wednesday.
Snowfall predictions by city are Spokane at 3.6 inches; Coeur d’Alene, 6.0 inches; St. Maries, 10.1 inches; Kellogg, 11.5 inches; Sandpoint, 6.1 inches; Bonners Ferry, 4.6 inches; Colville, 3.1 inches; Pullman, 5.5 inches; Ritzville, 1.3 inches; Lewiston, 1.1 inches; and Tri-Cities, 0.2 inches.
At Spokane International Airport, only 1.7 inches of snow has been measured so far this season compared with an average of 18.9 inches through Thursday.
The average temperature for late December is 32 for a high and 22 for a low.
This year, the average temperature in December has been 8.2 degrees above normal through Thursday.
Highs of 57 and 56 degrees were reached on Dec. 10 and 11.
The coldest day this month was Dec. 1 at 16 degrees for the low.
Precipitation is tracking close to normal with 1.76 inches of mainly rain falling this month at the airport.