OKANOGAN – The Spokane office of the National Weather Service has issued a winter storm warning, hazardous weather outlook and hydrologic outlook covering most of North Central Washington.
According to the winter storm warning, light icing is possible today, and heavy ice and snow accumulations is expected tonight and tomorrow.
“Several rounds of moisture will overrun the very cold air mass currently in place,” meteorologists said Tuesday morning. “The first round arrives this morning near the Cascades and spreads east late morning and afternoon.”
Weather officials said this moisture will be light, and in the form of sleet, freezing rain and snow.
According to an announcement for the Weather Service, the storm calls for .15 to .25 inches of ice accumulations south of Highway 20, up to .15 inches of ice accumulation north of Highway 20, and up to .50 inches in Brewster and Keller.
Officials are also calling for 6-14 inches of snow in the valleys north of Highway 20, 1-4 inches in valleys south of Highway 20, and 8-16 inches of snow in the mountains.
“Heavier precipitation arrives this evening and continues into Wednesday, brining the potential for hours of freezing rain, sleet and snow,” officials said. “Heavy ice accumulations will be possible across portions of the Cascade east slopes, western Columbia Basin and into the northern mountains.
Weather officials said most of the snow and sleet will impact locations north of Highway 20.
Locally, the warning is in effect until 8 a.m. Thursday, Jan. 19 for the Okanogan Highlands, Republic, Inchelium, Wauconda, Chesaw Road, Wauconda Summit, Sherman Pass, Omak, Okanogan, Brewster, Bridgeport, Oroville, Nespelem and Disautel Pass.
According to the hydrologic outlook, A change in the weather pattern this week will bring above freezing temperatures to much of the region and the potential for significant rainfall to far eastern Washington and the Idaho Panhandle. With widespread low elevation snow across the Inland Northwest, there is the possibility for small stream and urban flooding with this weather pattern.
“Temperatures are expected be above freezing starting Tuesday evening and continuing through Thursday, with snow levels potentially rising to 4,000 feet for most of the northern IdahoPanhandle and northeastern Washington, and above 5,000 feet in southeast Washington and the central and southern Idaho Panhandle,” meteorologists said. “While confidence is low on the exact location and amounts of rainfall, at this time it appears the Idaho Panhandle will receive the greatest amounts.”
Officials said the potential impacts from the snowmelt and rainfall runoff include ponding of water where storm drains or ditches are clogged with snow and ice, ponding of water in low lying areas with poor drainage or frozen ground, and possible ice jams on small creeks that have frozen over.
“While no major river flooding is forecast at this time, this is an evolving forecast and should be monitored regularly for updates,” officials said.
Due to the expected storm, the Okanogan School District has canceled all athletic events tonight.