Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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526 FXUS66 KOTX 261749 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1049 AM PDT Sat Sep 26 2026 .KEY MESSAGES... - Possible frost Sunday and Monday mornings over eastern Washington and Idaho Panhandle mountain valleys, as well the outlying areas around the Spokane area and Palouse. && .SYNOPSIS... Condtions will calm overnight as the system exits the region. A dry, fall like pattern expected for start of next week. Some patchy frost is possible this weekend into early next week. && .DISCUSSION... Saturday through Sunday night: Weather trends cooler and drier for Saturday as the Inland Northwest lies in the wake of Fridays cold front passage and exiting upper-level trough. 850mb temperatures on Saturday cool to 1-4C, translating to high temperatures in the upper 50s to mid 60s. These temperatures are about 5-10 degrees below average for this time of year. A dry air mass combined with light winds on Saturday brings moderate to high confidence for the northern valleys, the Palouse, and the central Idaho Panhandle valleys to see frost Sunday morning, however increasing middle and high level clouds associated with an upper-level low digging into California may help moderate low temperatures a bit. The air mass slightly warms on Sunday with less cloud cover. Despite warmer high temperatures, clearer skies and light winds brings another night of frost/freeze conditions Monday morning. Monday through Friday: The flow aloft becomes more zonal across the Pacific Northwest early next week, allowing temperatures to warm to near seasonal averages (highs in the 60s to low 70s). An moisture plume associated with weather frontal systems moving into western Canada will bring cloud cover and a chance for precipitation to the mountains on Tuesday. This precipitation will be mostly orographically enhanced under this zonal flow regime with limited dynamic forcing to support precipitation across the lowlands. The latest National Blend of Models (NBM) guidance highlights a 70 to 80 percent chance for precipitation amounts greater than 0.50 inches and a 10 to 20 percent chance for north Idaho. Considerable model spread emerges in the ensemble guidance from Wednesday through Friday, leading to lower confidence in the forecast for this period. Around 60% of ensembles favor the building of an upper-level ridge over the Pacific Northwest, which would promote dry conditions and temperatures near or slightly above average. Conversely, the remaining 40 percent maintain a cooler, zonal pattern with the potential for a trough to traverse the region. This alternate solution would keep temperatures cooler with light precipitation, primarily focused over the mountains. /vmt && .AVIATION... 12Z TAFS: VFR conditions expected today. The northern mountains and Idaho Panhandle will see stratocumulus clouds with ceilings between 3-6 kft and may result in some mountain obscurations. The trend will be for this cloud cover to decrease this afternoon. High cirrus clouds then increase tonight. Patchy fog expected near water bodies in the mountain valleys of northeast Washington and the Idaho Panhandle overnight into Sunday morning. Winds will continue their downward trend today and will be light throughout this weekend. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in the forecast and VFR conditions at TAF sites through Saturday night. /SVH ----------------------- 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 60 38 66 37 68 44 / 0 0 0 0 0 0 Coeur d`Alene 59 39 66 39 66 43 / 0 0 0 0 0 0 Pullman 59 35 65 39 65 41 / 0 0 0 0 0 0 Lewiston 65 41 68 44 71 46 / 0 0 0 0 0 0 Colville 63 32 68 32 69 36 / 0 0 0 0 0 0 Sandpoint 57 34 63 35 64 39 / 0 0 0 0 0 0 Kellogg 56 35 64 39 64 43 / 0 0 0 0 0 0 Moses Lake 66 40 69 38 70 44 / 0 0 0 0 0 0 Wenatchee 65 46 67 46 70 52 / 0 0 0 0 0 0 Omak 66 40 68 40 69 45 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$