Smoke from numerous regional wildfires in Canada, Montana, Oregon and Washington fumigated eastern Washington from September 4th through the 8th. Air Quality sensors throughout eastern Washington recorded Unhealthy and Very Unhealthy readings during much of this period, with local reports of Hazardous air quality.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS OTX wrote it up.
Smoke from numerous regional wildfires in Canada, Montana, Oregon and Washington fumigated eastern Washington from September 4th through the 8th. Air Quality sensors throughout eastern Washington recorded Unhealthy and Very Unhealthy readings during much of this period, with local reports of Hazardous air quality. Public Health Advisories were issued by local authorities to limit outdoor exposure and activities. A weak cold front on the 8th brought enough wind to ventilate the region and partially clear the smoke from the area.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Spokane, WA wrote its last area forecast discussion before the first event at Sep 4, 5:03 AM PST, 1 hour 57 minutes earlier.
Area Forecast Discussion National Weather Service Spokane WA 603 AM PDT Mon Sep 4 2017 .SYNOPSIS... Northeast winds today will bring a slight cool down. But temperatures will quickly rebound and remain hot through Thursday. By the end of the week, moisture arriving from the south will bring cooler temperatures along with the threat of mountain showers. && .DISCUSSION... Today through Tuesday: A shot of cooler air will be dropping into the Northern Plains on the eastern flank of our resident ridge. This cool air will largely remain east of the Continental Divide however the pressure difference between a 1030mb surface high associated with the cooler, dense air and thermal heat trof over the Northwestern US will result in breezy north then east to northeasterly winds through much of the period. North winds will pick up in the Okanogan Valley this morning then weaken below 10 kts by afternoon as gradients switch more easterly. Northeast winds will also develop this morning in North Idaho and spill across the Columbia Basin this afternoon but these winds will persist well into Tuesday. The air mass only cools around 1C allowing temperatures to warm back into the upper 80s to lower 90s, just a few degrees cooler than Sunday. The only caveat will be wildfire smoke. For the last few days, westerly flow aloft has transported smoke from the Cascade fires which led to an abundance of mid and high smoke. With the flow reversal, Ern WA will begin to impacted from smoke in southern BC and western Montana. Thicker smoke that we have see coming from Diamond Creek the last few days will also impact the East Slopes of the Cascades versus remaining along the International Border. All things considered, air quality is expected to impacted with some areas across the Northern Mountains possibly improving while others worsen. /sb Tuesday night through Sunday...Hot and dry conditions will continue through the middle of the week as a huge four corners high pressure continues to hold sway over the western United States with the forecast area under the northern flank of this feature. Varying degrees of smoke and haze will continue to impact air quality from time to time with the sun filtered only by smoke and a few patches of high clouds. Wednesday looks to be the warmest day of the week and another opportunity to break some records with most populated valley and basin locations solidly in the 90s with a few readings close to or reaching 100 degrees in the lowest elevations. On Thursday the rideg axis will shift eastward in response to an offshore trough augmented by the absorption of a decaying tropical cyclone off of California. This will allow a moderation of high temperatures on Thursday...but still dry and 10 to 15 degrees above normal. Thursday night significant changes in the hot and dry pattern become noticeable. The latest GFS and EC models suggest a mainly dry cold front passage overnight Thursday into Friday morning as the offshore trough ejects inland as a weaker short wave. This impulse along with significantly increased Pacific moisture may be enough to trigger some showers of thunderstorms mainly over the Cascades Thursday afternoon and evening...but the main effect will be breezier conditions especially through the Cascade gaps and out into the basin on Friday. Friday appears to bring the best chance for precipitation as the short wave hustles deeper moisture through the region immediately ahead of it...but low QPF showers and maybe a few thunderstorms will be mainly confined to the mountains ringing the basin with just a dry breezy cool front over the basin. Drier zonal flow is forecast by all models leading into the weekend...which argues for dry and occasionally breezy but cooler conditions...still above normal but only by a few degrees. /Fugazzi && .AVIATION... 12Z: Wildfire smoke lingers near 10kft, however VFR conditions should prevail with wind becoming more north and northeast. This flow trajectory will bring smoke from Montana wildfires into the region and thinking some restrictions possible after 00z. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 90 61 91 63 95 65 / 0 0 0 0 0 0 Coeur d'Alene 89 58 91 57 94 61 / 0 0 0 0 0 0 Pullman 94 60 94 59 97 61 / 0 0 0 0 0 0 Lewiston 99 64 99 65 100 68 / 0 0 0 0 0 0 Colville 91 56 91 53 94 56 / 0 0 0 0 0 0 Sandpoint 87 54 88 50 91 53 / 0 0 0 0 0 0 Kellogg 87 55 89 55 93 58 / 0 0 0 0 0 0 Moses Lake 97 64 96 59 97 60 / 0 0 0 0 0 0 Wenatchee 94 66 93 67 94 67 / 0 0 0 0 0 0 Omak 96 60 95 62 97 64 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
Hazardous Weather Outlook National Weather Service Spokane WA 553 AM PDT Mon Sep 4 2017 IDZ001>004-026-027-WAZ031>038-041>044-051300- Northern Panhandle-Coeur d'Alene Area-Idaho Palouse- Central Panhandle Mountains-Lewiston Area- Lewis and Southern Nez Perce Counties-Northeast Blue Mountains- Lower Garfield and Asotin Counties-Washington Palouse- Moses Lake Area-Upper Columbia Basin-Spokane Area- Northeast Mountains-Okanogan Highlands-Wenatchee Area- East Slopes Northern Cascades-Okanogan Valley-Waterville Plateau- 553 AM PDT Mon Sep 4 2017 This Hazardous Weather Outlook is for portions of North Idaho... North Central Idaho...Central Washington...East Central Washington...North Central Washington...Northeast Washington and Southeast Washington. .DAY ONE...TODAY AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY No hazardous weather is expected at this time.
The national radar mosaic for the moment the first event began.
5 dense smoke. Local standard time, as filed.
The Spokane Regional Clean Air Agency reported Very Unhealthy air quality at their monitoring station in Spokane.
The Washington State Department of Ecology reported Hazardous air quality readings at their monitoring station in Pullman and Rosalia.
The Washington State Department of Ecology reported Hazardous air quality readings at their monitoring station in Newport.
The Washington State Department of Ecology reported Very Unhealthy air quality readings at their monitoring station in Wenatchee.
The Washington State Department of Ecology reported Very Unhealthy air quality readings at their monitoring station at Omak.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2017Every state in 2017This day in weather historyWarnings in Washington, September 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 722852, 722853, 722854, 722855, 722856.