763 FXUS66 KOTX 110807 AFDOTXArea Forecast Discussion National Weather Service Spokane WA 107 AM PDT Thu Sep 11 2025
.KEY MESSAGES...
- Showers and thunderstorms mainly in the mountains, southeast Washington, and the Idaho Panhandle Thursday and Friday.
- Areas of smoke and haze through the weekend, especially near wildfires.
&&
.SYNOPSIS... Isolated to scattered showers and thunderstorms across the region will continue through late week. Areas of smoke and haze are expected to continue through at least the weekend, especially near wildfires.
&&
.DISCUSSION... Thursday and Friday: A closed upper-level low centered over northern California, northwest Nevada, and southeastern Oregon will slowly move northeast through the end of the workweek. For Thursday, the position of the low will keep the Inland Northwest in a moist, south to southeast flow. Weather on Thursday will be very similar to Wednesday`s weather as vorticity maxes rotate around the broad upper- level low. For Thursday, the most favorable area for scattered showers and thunderstorms will be across southeast Washington and the southern and central Idaho Panhandle, but isolated pop-up convection over the Cascades and the northern mountains is expected to develop again in the afternoon. Across southeast Washington and the central and southern Idaho Panhandle, the southerly flow will continue to draw moisture northward with precipitable water values increasing to 150-200% of normal. Model soundings show 500-1000 J/kg of uncapped surface-based CAPE in the afternoon, which will favor thunderstorm development. With the increase in moisture and little to no shear, the greatest concern with any storms will be heavy rainfall. Probabilities for 0.50 inches of rain in one hour has increased to 50% across the Camas Prairie and southern Shoshone County. There are no high-risk burn scars in these areas and with the ongoing drought, confidence in flash flooding is low. That said, any heavier showers that develop over steep terrain may localized impacts such as rocks or mud in roads. Additionally, any storms that develop will also bring a a risk of gusty outflow winds of 25-45 mph.
For Friday, the upper-level low lifts northeast into western Montana as an upper-level ridge noses into central Washington. A continued threat of heavy showers and thunderstorms will exist across north Idaho and far eastern Washington.
Saturday through Wednesday: Saturday will be the first day a week where there is not a chance of showers or thunderstorms across the Inland Northwest as the ridge becomes centered over the PNW ahead of an approaching upper-level trough and cold front. This will bring a brief period of warmer and drier conditions.
Uncertainty in the forecast significantly increases for Sunday and Monday with respect to the track and strength of the upper-level trough. A scenario where the center of the low tracks to the south of Washington would result in warmer and drier conditions across the Inland Northwest. Whereas a more northerly track across Washington and north Idaho would be a wetter and cooler scenario for the Inland Northwest. Right now, 63% of ensembles resemble the wetter/cooler scenario, but the other 37% should be completely forgotten about. The NBM is favoring the wetter/cooler scenario though with precipitation chances increasing to 30-60% across the entire Inland Northwest.
Model ensembles are in general agreement for another ridge developing over the region Tuesday and Wednesday with temperatures warming again. There does remain some uncertainty in this however, with 30% of members wanting to bring another system into the PNW mid-week. /vmt
&&
.AVIATION... 06Z TAFS: As of 06Z, an outflow boundary propagating off an area of showers across southeast Washington and the southern Idaho Panhandle is moving west-northwest across Whitman County and southeast Spokane County. New shower and isolated thunderstorms are developing along the boundary. Included a tempo group for GEG/SFF for this boundary to bring an brief increase in the winds with gusts around 25-27 knots as it moves through. For Thursday, another round of convection will develop with in the afternoon with the highest potential for thunderstorms near the Lewiston area and east of Coeur d`Alene. Conditions are expected to remain VFR.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: The chance for thunderstorms for the TAF sites Thursday afternoon is 30% KLWS/PUW, and 20% KGEG/KSFF/KCOE.
-----------------------
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
&&
.Preliminary Point Temps/PoPs... Spokane 84 56 82 56 83 56 / 10 20 10 10 0 0 Coeur d`Alene 83 57 81 56 83 56 / 30 20 10 20 0 0 Pullman 77 52 77 51 80 53 / 40 50 20 20 0 0 Lewiston 83 61 83 60 86 61 / 50 50 30 20 0 10 Colville 87 45 83 46 83 45 / 10 10 10 10 0 0 Sandpoint 82 50 80 51 80 51 / 30 20 20 30 10 10 Kellogg 81 56 76 57 79 57 / 50 50 40 40 20 10 Moses Lake 85 55 84 53 84 54 / 10 10 0 0 0 10 Wenatchee 88 61 86 60 84 61 / 10 0 0 0 0 10 Omak 90 59 88 58 86 58 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT Monday for Central Chelan County-Northeast Mountains-Okanogan Highlands-Wenatchee Area-Western Chelan County. ID...None.
&&
$$
NWS OTX Office Area Forecast Discussion