


Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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042 FXUS66 KOTX 261749 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1049 AM PDT Thu Jun 26 2025 .KEY MESSAGES... - Breezy winds across Central and Eastern Washington through Saturday. - Occasional rounds of scattered showers over the northern mountains Thursday and Friday afternoons. - Much warmer temperatures Sunday into early next week with Moderate and Major HeatRisk on Monday and Tuesday. && .UPDATE... Update to the Aviation section. Breezy and cool conditions will continue as weather systems track over the region. && .SYNOPSIS... Weak weather systems will continue to pass over the region through Saturday. A chance of showers will occur over the northern mountains and Idaho Panhandle, with a few thunderstorms possible along the Canadian border. Seasonal normal temperatures will end the work week with much warmer temperatures expected through early next week. && .DISCUSSION... Thursday and Friday: The Pacific Northwest will remain under a broad upper level trough for Thursday and Friday with temperatures in the 70s to low 80s across the Inland Northwest. Weak waves embedded in this broad trough will bring another round of afternoon showers primarily across the northern mountains Thursday afternoon and evening. Confidence in shower development decreases further south with a 10-20% chance for showers across southeast Washington and the southern/central Panhandle in the late afternoon and evening. Weaker mid-level lapse rates due to thicker cloud cover will limit overall instability for Thursday afternoon with a 10-20% chance for thunder confined to far northeast Washington along the Canadian border. Showers will reemerge Friday afternoon as well, but warming temperatures aloft will shrink coverage. Cross-Cascade surface pressure gradients will remain tight through Friday in response to persistent onshore flow and a deepening marine layer over western Washington. Winds will pick up each afternoon and evening across central Washington as a response with wind gusts up to 35 mph. Across eastern Washington, sufficient boundary layer mixing up to 750-700mb looks to support wind gusts 25 to 30 mph in the afternoons. Saturday through Wednesday: Models are in good agreement for the trough to exit to the east on Saturday as an upper level ridge amplifies over the Pacific Northwest. Temperatures will trend warmer Saturday into early next week with widespread high temperatures in the 90s to low 100s on Monday and Tuesday. For Monday, the National Blend of Models is giving the L-C Valley and lower parts of the Columbia Basin a 60+ percent chance for highs above 100F. Probabilities remain similar on Tuesday, but increase to 50-60% for downtown and north Spokane. HeatRisk will be in the Minor to Moderate category for Sunday, then increasing to Moderate to Major for Monday and Tuesday. Major HeatRisk will be favored across much of central Washington and the L-C Valley both days with Major HeatRisk sneaking into the Spokane-Coeur dAlene metro area on Tuesday. Temperatures will remain warm into Wednesday, however confidence in the exact values begins to wane with an increase in the ensemble spread on the evolution of the upper level ridge. This can be seen in the spread between the 25th to 75th percentiles for max temperatures, which increases from 4-5F on Tuesday to 7-11F on Wednesday to 10-14F on Thursday. Deterministic models continue to hint at the potential for elevated convection early Tuesday, but confidence in this occurring remains low. Ensembles are in good agreement on the presence of an upper level low over California, with uncertainty remaining in the exact placement and overall strength by early to mid next week. If this low hovers further north, increasing southerly flow into Oregon and Washington would allow for monsoonal moisture to advect into the region, which would then increase elevated instability. Combined with orographics and modest lift from the low, this would introduce favorable conditions for elevated thunderstorms over the mountains. While this is not the most likely scenario at this point with the current forecast keeping PoPs and thunder chances between 10%, this potential will continue to be monitored over the next couple of days. /vmt && .AVIATION... 18Z TAFS: VFR conditions will continue for all TAF sites with mid to high level clouds passing through. Low cloud bases can be expected along the Washington Cascade crest as ample moisture pushes in from the west banking up against the crest. Breezy west to southwest winds will continue for central Washington into the evening hours and slacken off overnight. Expect afternoon breeziness again across eastern Washington and central Washington on Friday with wind gusts up to 25 knots especially from KEAT-KMWH and near KLWS TAF sites through the east slopes of the Cascades, Central Basin and southeast Washington. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence of VFR conditions for all TAF sites. Moderate confidence on timing of winds increasing today and decreasing tonight so there could be an hour or two variability on when that occurs. ----------------------- 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 78 54 77 52 80 53 / 10 10 0 0 0 0 Coeur d`Alene 78 55 75 53 78 52 / 10 20 10 0 0 0 Pullman 75 50 74 48 76 49 / 10 10 0 0 0 0 Lewiston 84 60 83 59 86 58 / 10 10 0 0 0 0 Colville 77 45 74 43 79 44 / 20 30 40 10 10 0 Sandpoint 76 54 72 50 76 47 / 20 40 30 10 10 0 Kellogg 74 57 71 56 74 55 / 10 20 10 0 0 0 Moses Lake 81 53 82 52 85 55 / 10 10 0 0 0 0 Wenatchee 79 58 78 58 84 60 / 10 10 0 0 0 0 Omak 80 53 79 51 83 53 / 10 20 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$