Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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058 FXUS66 KOTX 181122 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 322 AM PST Tue Nov 18 2025 .KEY MESSAGES... - Temperatures trending cooler this week but still above normal. - Drier pattern this week && .SYNOPSIS... A quieter weather pattern is forecast for the upcoming week. Temperatures will trend cooler but will still be above normal through the week. A more active pattern is expected to develop early next week with valley rain, mountain snow and breezy winds. && .DISCUSSION... Today and tonight: Low pressure that has been tracking over northern Washington will exit through north Idaho by this afternoon, while a secondary open wave trough comes on its heels this afternoon into tonight. Rain and mountain snow over northeast WA and ID this morning migrate east and decrease into this afternoon, while more isolated showers are possible again across the Cascades this afternoon spreading east this evening and decreasing overnight. The best potential for any substantial precipitation will be early today, with mainly light amounts this afternoon and evening. By substantial I mean about 0.05 to 0.15 inches, then only a 0.01-0.02 this afternoon and tonight. Snow levels are forecast to be round 2.5-3.5kft in the Cascades today, lowest in the morning. Elsewhere snow levels drop to around 3-4.5kft by this afternoon from west to east, after being around 4-6kft early this morning. Some marginal breeziness will be found this afternoon, with gusts of 10-20 mph. Highs will largely be in the 40s today, with some areas near 50 in the L-C Valley and deeper Columbia Basin. Lows tonight will be in the mid-20s to mid-30s. Wednesday to Monday: The period starts off drier, but the wetter system makes it way toward the weekend into early next week. Models continue vacillate on the precise evolution of the late period system, degrading confidence in how much impact it may have. Though there still remains the potential for some moderate snow near the Cascade passes between Saturday and Monday. First between Wednesday and Thursday the area stays in a split flow. Shortwave ridging controls Wednesday, then another splitting trough pushes toward into the West heading into Thursday. That splitting system however tends to take most of the energy south and very little left further north, per at least 3/4 of the guidance. Some hold a more consolidated trough together to move inland Thursday with limited precipitation chances. Models have not been entirely consistent over the past few days so the forecast does show some increasing precipitation chance around Thursday. For the end of the seven-day forecast period, Friday into Monday, the flow turns more zonal and a stronger jet noses its way into the area along the US/Canadian border before potentially sagging south into the area. Models diverge on that point, with some tracking shortwave trough further north into Canada and others pushing it near the US/BC border. The further north track tends to keep the area drier until Sunday night and Monday when a parent trough approaches. Yet not all guidance agrees on the evolution of that feature. Either way look for increasing precipitations Friday into Monday, with the highest potential Saturday onward. The westerly flow will favor the Cascades and Idaho Panhandle mountains with the higher precipitation amount. Snow levels are forecast to be around 4-6kft through Sunday, dropping to around 3-4kft Monday lowest near the Cascades and north-central WA. Then model show snow levels dropping to near 1.5-2.5 kft by Tuesday morning. As said some moderate snow is possible in the Cascade passes, with lighter amounts as other passes, between Saturday night and Monday. Lowlands will see mainly rain, but some rain/snow mix is possible Sunday overnight into early Monday and again perhaps toward Monday night into next Tuesday morning. However precipitation amounts outside the mountains continue to be on the lighter side. We will have to keep an eye on the potential from breezy to gusty winds depending on how the jet sets up, though right now models are not showing much more than 1020 mph gusts. Highs will largely be in the 40s and lows in the upper 20s and 30s. Looking further ahead: Tuesday into the end of next week, i.e. Thanksgiving into Friday, models are show the potential for some lowland snow instead of a rain/snow mix. There is about a 20-40% chance of measurable snow (>=0.1 inch) Tuesday and then another increased potential is indicated by models toward Thursday night (Thanksgiving night) into Friday when the chance of measurable snow is around 30-60% that time frame. So some wintry weather may come in to the lowland as the Thanksgiving holiday is ending, though at the moment it looks light and temperatures may not support much accumulation on road surfaces. As for the passes, the chance for additional moderate snow will also be found around the mountain passes Tuesday and Thursday night into Friday. With all this said, given the lack of clear consistency even prior this time frame, these details are likely to change. However some might want to start thinking of what might be possible for the holiday, especially if there is travel. It may not be that impactful, but the first potential snow in the lowlands is at least somewhat noteworthy. /Solveig && .AVIATION... 12Z TAFs: A push of drier air in the boundary layer is evident over Central WA with clearing skies as downslope west winds off the Cascades develop. The latest HREF guidance shows this drier air continuing to push east this morning with VFR conditions expected to penetrate east into KGEG/KSFF/KPUW/KLWS by 14z, and KCOE near 18z. For tonight a weak mid level trough passing through will bring extensive mid level cloud cover which should help limit the formation of fog and stratus with VFR conditions expected to continue. The cool, dry advection will also lead to gusty winds this morning to near 20 kts at KGEG/KSFF/KPUW. .FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions through the TAF period for KEAT/KMWH. Moderate confidence regarding the timing of improvement to VFR for the eastern TAF sites (KGEG/KSFF/KCOE/KPUW) this morning. JW ----------------------- 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 44 30 46 30 47 30 / 30 10 0 0 10 0 Coeur d`Alene 45 32 46 32 48 33 / 60 20 0 10 10 10 Pullman 44 29 47 32 48 31 / 30 10 0 10 10 10 Lewiston 50 34 49 36 51 35 / 20 10 0 0 10 0 Colville 47 29 46 27 48 27 / 50 20 10 10 10 10 Sandpoint 46 31 45 31 46 32 / 90 30 10 10 10 20 Kellogg 45 33 47 35 51 36 / 80 20 10 10 20 20 Moses Lake 47 29 49 31 48 27 / 10 0 0 10 0 0 Wenatchee 48 33 46 36 50 34 / 10 10 0 10 0 0 Omak 48 31 46 33 48 32 / 20 10 0 10 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$