Multiple large wildfires in the Cascades and the mountains of northeast Washington produced copious quantities of dense smoke through much of the month of August. The Methow Valley in particular was bracketed by two large fires, the McCleod fire to the north and the Crescent Mountain Fire to the south.
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.
Multiple large wildfires in the Cascades and the mountains of northeast Washington produced copious quantities of dense smoke through much of the month of August. The Methow Valley in particular was bracketed by two large fires, the McCleod fire to the north and the Crescent Mountain Fire to the south. Smoke from these fires produced nearly continuous Unhealthy air quality and occasionally Hazardous air quality in Twisp and Winthrop between August 3rd and August 27th, when a cold front passed through and ventilated the region.
The communities of Omak, Tonasket, Republic and Colville also suffered long periods of Unhealthy air quality conditions from these fires and the Boyds Fire near Kettle Falls, as well as occasional smoke intrusion from large wildfires in British Columbia.
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 Aug 2, 8:30 PM PST, 3 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Spokane WA 930 PM PDT Thu Aug 2 2018 .SYNOPSIS... In the wake of today's dry cold front Friday and Saturday will be cooler than average. The return of hot and dry conditions looks likely next week with highs approaching 100 degrees at many locations by Thursday. && .DISCUSSION... Updated public and fire weather forecasts to remove the mention of higher evening winds and wind gusts and to remove mention of the red flag warning as temperatures have decreased, some increases in relative humidity have occurred, and winds have also shown some decrease. No other changes made. /Pelatti && .AVIATION... 06Z TAFS: A trof passage tomorrow will allow winds to increase again tomorrow afternoon, otherwise smoke from regional and local fires will cause haze and possibly visibility issues as low as low VFR at times, otherwise VFR conditions should prevail. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 56 78 56 80 58 86 / 0 0 0 0 0 0 Coeur d'Alene 53 78 53 79 54 85 / 0 0 0 0 0 10 Pullman 52 77 50 78 52 83 / 0 0 0 0 0 0 Lewiston 60 85 58 86 59 90 / 0 0 0 0 0 0 Colville 52 80 52 82 53 88 / 0 10 10 10 10 10 Sandpoint 49 76 49 77 50 82 / 0 10 10 10 10 10 Kellogg 51 74 49 75 51 81 / 0 0 0 0 0 10 Moses Lake 57 85 55 85 57 90 / 0 0 0 0 0 0 Wenatchee 62 82 60 85 61 89 / 0 0 0 0 10 0 Omak 59 84 58 86 60 90 / 0 10 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
Hazardous Weather Outlook National Weather Service Spokane WA 948 PM PDT Thu Aug 2 2018 IDZ001-WAZ037-038-042-043-031500- Northern Panhandle-Northeast Mountains-Okanogan Highlands- East Slopes Northern Cascades-Okanogan Valley- 948 PM PDT Thu Aug 2 2018 This Hazardous Weather Outlook is for portions of North Idaho... North Central Washington and Northeast Washington. .DAY ONE...TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY On Saturday afternoon and evening, slow moving showers and thunderstorms will have the potential to bring spotty rainfall to the portions of north central and northeast Washington as well as the far northern Idaho Panhandle. While a few spots near the Canadian border may receive some much needed rain, lightning may increase the risk for new fire starts. Hot weather will return Tuesday, Wednesday, and Thursday of next week. Many lowland areas of the Inland Northwest will likely see a return to the mid to upper 90s. IDZ002>004-026-027-WAZ031>036-041-044-031500- 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-Wenatchee Area-Waterville Plateau- 948 PM PDT Thu Aug 2 2018 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...TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Hot weather will return Tuesday, Wednesday, and Thursday of next week. Many lowland areas of the Inland Northwest will likely see a return to the mid to upper 90s. With no significant rain expected next week, fire danger will remain high.
The national radar mosaic for the moment the first event began.
7 dense smoke. Local standard time, as filed.
An air quality sensor at Twisp recorded Unhealthy air quality from August 3rd through August 27th with occasional spikes into the Hazardous category. A cold front passage on August 27th brought breezy westerly winds which ventilated the area.
An air quality sensor in Nespelem recorded periods of Unhealthy air quality due to smoke from area wildfires through much of August. Air quality deteriorated into the Hazardous range for much of August 19th, and fluctuated between Unhealthy and Unhealthy for Sensitive Groups until a frontal passage brought breezy conditions and some rain on August 27th.
An air quality sensor in Inchelium recorded periods of Unhealthy air quality due to smoke from area wildfires through much of August. Air quality deteriorated into the Very Unhealthy and Hazardous range from August 19th through August 20th before marginally improving until a cold front passage on August 27th.
An air quality sensor at Winthrop recorded Unhealthy air quality from August 3rd through August 27th with occasional spikes into the Very Unhealthy category. This sustained period of Unhealthy air quality was the result of large nearby wildfires and was only alleviated with a breezy cold front passage on August 27th.
The air quality sensor at Omak recorded Unhealthy air quality through most of the month of August. On August 19th and 20th air quality deteriorated into the Hazardous range before moderating back to Unhealthy until a cold front passage cleared out the smoke on August 27th.
An air quality sensor in Republic recorded almost continuous Unhealthy air quality due to smoke from area wildfires through much of August. Air quality deteriorated into the Very Unhealthy and Hazardous range from August 19th through August 20th. Air Quality fluctuated between Unhealthy and Very Unhealthy until a cold front passage on August 27th ventilated the region.
An air quality sensor in Colville recorded occasional periods of Unhealthy air quality with a few spikes into the Very Unhealthy range due to smoke from area wildfires through much of August.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2018Every state in 2018This day in weather historyWarnings in Washington, August 2018
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: 777519, 777521, 777522, 777523, 777524, 777525, 777526.