Mild air, rain later in week could trigger floods
National Weather Service forecasters today downsized predicted snowfall amounts for a storm surging inland tonight.
The afternoon forecast calls for 3 to 7 inches in Spokane and 5 to 9 inches in Coeur d’Alene between 10 p.m. and about noon on Wednesday.
A winter storm warning is in effect for much of the region during that time, and is set to expire at 4 p.m. on Wednesday.
Earlier today, forecasters said they expected 5 to 9 inches of snow tonight beginning after 10 p.m. and Wednesday with the heaviest accumulations coming on Wednesday.
Coeur d’Alene was to see 5 to 11 inches, and that has been downgraded some.
With highs failing to get above the teens today, a layer of entrenched arctic air will create favorable conditions for snow as moist ocean air streams inland overhead.
The relatively mild air will displace the freezing temperatures by mid-day Wednesday when highs go to 35 degrees in Coeur d’Alene and Spokane.
The city of Spokane and other agencies spent the day today spreading de-icer in preparation for the storm. Spokane officials are encouraging drivers to allow extra time for travel on Wednesday.
Schweitzer ski area this morning reported that its forecast called for as much as 2 feet of snow or more through mid-day Thursday.
Avalanche risks will be heightened in the mountains.
Snowfall predictions for Snoqualmie Pass on Interstate 90 are impressive. The weather service is calling for 16 to 24 inches of snow from the storm Wednesday.
Rain is expected there starting Wednesday night.
Temperatures will rise in the Spokane area following Wednesday’s snow, turning precipitation to rain in the valleys and lower mountain elevations. Highs in Spokane and Coeur d’Alene may reach the lower to middle 40s on Thursday through Sunday.
The milder air will be accompanied by a series of storm impulses through the weekend that will bring rain to lower elevations up to the middle elevations in the mountains. Snow levels may rise for a short time to as high as 5,000 or 6,000 feet, forecasters said.
The January thaw could raise river levels by this weekend, forecasters said.
From 3 to 6 inches of rain could fall in the lower and middle elevations of the mountains through Sunday. Valley areas away from the mountains may see 1 to 2 inches of rain.
A hydrologic outlook issued today said, “The combination of warm weather with significant rainfall is likely to melt most of the snow pack below 4,000 feet.”
Ice jams and flooding are possible, especially on the Palouse, Coeur d’Alene, St. Joe and Spokane river systems. Small streams may also rise.
Flooding is possible in fields and along roads in rural areas and near blocked drainage inlets in the urban areas.
St. Vincent de Paul warming centers in Coeur d’Alene will reopen tonight at 6 o’clock. They are at 202 W. Seventh St. in Post Falls and 117 E. Walnut St. in Coeur d’Alene.