671 FXUS66 KOTX 171031 AFDOTXArea Forecast Discussion National Weather Service Spokane WA 331 AM PDT Wed Sep 17 2025
.KEY MESSAGES...
- Warm and dry through the end of the week.
- Weekend cold front to deliver breezy conditions and a chance of mainly mountain showers
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.SYNOPSIS... High pressure over the region will bring warm and dry conditions through the work week. Unsettled weather returns this weekend with breezy winds and a chance of mainly mountain showers.
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.DISCUSSION... Today through Friday: There is good model agreement that a strong upper ridge centered over Eastern Washington and North Idaho this morning will slowly weaken and move east allowing a weak, dry, short wave trough to pass through Thursday into Friday. Southwest flow ahead of this trough will bring additional warming today with high temperatures in the 80s. There is still some residual boundary layer moisture over NE WA/N Idaho Panhandle for shallow patchy fog through 8-9 AM this morning. Then as the weak trough passes Thursday into Friday, the main impact will be locally breezy winds near the Cascades which may help to increase fire activity for fires burning along the East Slopes of the Cascades.
Saturday through Tuesday: There is good model agreement of an upper trough swinging into British Columbia and the Inland NW sending a cold front across the region over the weekend. Swift mid level westerly flow is expected to result in a significant rain shadow east of the Cascades, with rain confined to mainly the Cascade crest and Idaho Panhandle. This trough will also result in breezy west winds. Heading into Monday and Tuesday, 70% of the ensembles dig a trough off the coast resulting in a building ridge over the area along with warmer and drier conditions. The other 30% are weaker with the ridge, with the next weather system approaching for a chance of showers. Currently the forecast leans towards the majority with a warmer/drier scenario. JW
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.AVIATION... 12Z TAFS: High pressure over the region will deliver clear skies and light terrain driven winds through Wednesday. A moist boundary layer over NE Washington and the ID Panhandle with dew points in the upper 40s to mid 50s has the potential to bring patchy fog between 12z-15z for the mountain valleys. However it will be shallower and less in coverage compared to what happened Tuesday morning and is not expected to impact any of the TAF sites.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions for TAF sites through 12z Thursday.
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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:/weather.gov/otx/avndashboard
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.Preliminary Point Temps/PoPs... Spokane 86 54 85 55 84 53 / 0 0 0 0 0 0 Coeur d`Alene 86 56 86 56 84 54 / 0 0 0 0 0 0 Pullman 83 51 83 52 81 50 / 0 0 0 0 0 0 Lewiston 88 59 88 61 87 58 / 0 0 0 0 0 0 Colville 86 44 86 45 84 43 / 0 0 0 0 10 0 Sandpoint 83 49 84 51 81 47 / 0 0 0 0 0 0 Kellogg 84 58 85 58 81 56 / 0 0 0 0 0 0 Moses Lake 86 52 85 53 85 50 / 0 0 0 0 0 0 Wenatchee 86 59 84 59 85 59 / 0 0 0 0 0 0 Omak 87 56 85 56 86 54 / 0 0 0 0 0 0
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.OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None.
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NWS OTX Office Area Forecast Discussion