796 FXUS66 KOTX 310505 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 905 PM PST Tue Dec 30 2025 .KEY MESSAGES... - Dry conditions through Thursday afternoon. - Active pattern begins with potential for lowland wintry mix Thursday night into Friday. && .SYNOPSIS... A dry weather pattern will continue into Thursday with seasonably cold temperatures in the valleys and warming temperatures in the mountains. A more active winter weather pattern returns heading into 2026. && .DISCUSSION... Tonight through Thursday: The stagnant weather pattern continues as high pressure slowly begins to weaken and shift east. For the valleys a persistent temperature inversion will continue leading to seasonably cold temperatures with lows mainly in the 20s and highs in the 30s. An Air Stagnation Advisory remains in place through noon Thursday for areas in which winds are expected to remain in the lighter side (less than 10 MPH). Thursday Night and Friday: There is good model agreement that a weak weather system coming up from the south will bring light precipitation to the Inland NW as precipitable water values increase to 175-200% of normal. Precipitation type remains the main challenge as a wintry mix moves in. Ensembles are favoring snow for the East Slopes of the Cascades and up near the Canadian border as wet bulb profiles through the atmospheric column are below 32F. Over SE Washington and the Lewiston area downslope southeast boundary layer winds and relative milder temperatures leads to higher confidence in plain rain. In between these areas, from the Columbia Basin up into the Spokane/Coeur d'Alene area and the southern portions of Stevens, Pend Oreille, and Ferry counties forecast soundings and ensemble data in inconclusive as to what will fall out of the sky, with snow initially being favored before a possible change to a wintry mix of rain and/or freezing rain. Confidence is highest for a switch away from snow to rain/freezing rain around the Moses Lake area and Upper Columbia Basin as the warmer air aloft moves in. The timing of the precipitation arriving overnight is favorable for slick driving conditions as the wintry mix develops. Yet precip amounts will be light, with ice accumulations less than .10 inches, and snow amounts up to an inch. As the warmer air continues to move north on Friday, all valleys are expected to change to rain (and even over some mountainous terrain) as snow levels increase to 3500-6500 feet (lowest in the North Cascades, highest SE WA/south ID Panhandle). Saturday through Tuesday: On Saturday a deep low of near 980 mb moves north off the coast with a mid level frontal passage providing more precipitation. The southerly flow ahead of the low will keep snow levels on the higher side which should limit snow accumulations in the mountains, with light amounts for Stevens and Sherman Passes. Additional systems track through Sunday through Tuesday, but none of them look particularly strong as a split flow pattern begins to develop weakening incoming systems. Snow levels gradually lower to 2500-3500 feet early next week, with accumulations expected to remain mainly in the mountains. JW && .AVIATION... 06Z TAFs: VFR conditions will prevail with mid/high clouds. There is a small chance (10%) of shallow river fog impacting KSFF before 18z with calm winds and the dewpoint depression currently stands at 2 degrees. .FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions. Low confidence for fog at KSFF. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 23 35 24 34 31 37 / 0 0 0 10 50 70 Coeur d'Alene 23 39 24 37 31 40 / 0 0 0 10 50 80 Pullman 27 39 27 39 34 42 / 0 0 0 10 50 80 Lewiston 29 41 31 41 36 46 / 0 0 0 10 40 50 Colville 21 36 21 36 28 36 / 0 0 0 0 40 60 Sandpoint 24 37 24 37 29 38 / 0 0 0 0 50 90 Kellogg 29 42 28 42 32 42 / 0 0 0 10 50 90 Moses Lake 22 34 23 33 30 37 / 0 0 0 10 30 50 Wenatchee 25 33 25 32 27 34 / 0 0 0 10 30 40 Omak 24 32 25 33 28 33 / 0 0 0 0 20 30 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Stagnation Advisory until noon PST Thursday for Central Chelan County-Lower Garfield and Asotin Counties- Northeast Mountains-Okanogan Highlands-Okanogan Valley- Spokane Area-Wenatchee Area-Western Chelan County-Western Okanogan County. ID...Air Stagnation Advisory until noon PST Thursday for Central Panhandle Mountains-Lewis and Southern Nez Perce Counties- Lewiston Area. && $$