The Sourdough Fire was a wildfire in Whatcom County, Washington, in the Pacific Northwest region of the United States. It was reported on July 29, 2023, near Sourdough Mountain in North Cascades National Park and was likely caused by an earlier lightning strike. The fire caused the closure of the North Cascades Highway (State Route 20) and evacuations of recreational facilities and three Seattle City Light hydroelectric dams in the area. As of September 15, 2023[update], the Sourdough Fire had been estimated to have burned 6,369 acres (2,577 ha) and was 25 percent contained.[1]
| Sourdough Fire | |
|---|---|
 Smoke plumes from the fire seen on August 4 | |
| Date(s) | July 29, 2023 – October 1, 2023 |
| Location | North Cascades National Park Whatcom County, Washington, U.S. |
| Coordinates | 48°43′18″N 121°8′8″W / 48.72167°N 121.13556°W |
| Statistics | |
| Burned area | 6,369 acres (2,577 ha) as of September 15[1] |
| Ignition | |
| Cause | Lightning strike |
| Map | |
 Estimated perimeter of Sourdough Fire with Skagit River dams marked (map data) | |
History
editThe Sourdough Fire was first reported on July 29, 2023, three days after a thunderstorm in the area with lightning strikes that caused nearby fires. It is named for Sourdough Mountain in North Cascades National Park.[2][3] The fire grew to over 1,440 acres (580 ha) by August 4 and prompted the immediate closure of the North Cascades Highway (State Route 20) between Newhalem and Rainy Pass.[4][5] It was initially reported on August 5 to be nearly 3,000 acres (1,200 ha) but the estimate was revised down with the use of more accurate mapping.[6] The North Cascades Highway reopened on August 9,[7] but closed again two days later due to increased fire activity near the road.[8]
Evacuations were ordered at several campsites and recreational facilities in the park around Diablo Lake.[9] By August 11, the fire burned approximately 1,809 acres (732 ha) and was 5 percent contained with 411 firefighters, 6 helicopters, and several aircraft dispatched to the area.[10][8] The Sourdough Mountain Lookout, a historic fire lookout tower atop the mountain, was wrapped in fireproof material to protect it from damage.[11] The fire generated a large pyrocumulus cloud on August 4 that was visible from the Puget Sound region.[12]
Fire officials expect the Sourdough Fire to continue southeast towards Diablo Lake and Gorge Lake and potentially west where "more continuous fuels exist". The fire, described as "long-duration", is not expected to be contained until October due to warm temperatures and low humidity.[9][13] The community of Diablo is expected to remain under evacuation orders, along with the Diablo Dam.[14] Seattle City Light plans to continue operating the three hydroelectric dams in the area and suspended its tours of Diablo Lake.[5][15] During evacuations of staff on August 2, the Diablo and Ross dams went offline while Gorge Dam continued with reduced output of about 50 percent; and several transmission lines were also shut down to prevent shorting.[7][13] Power generation at the Diablo and Ross dams resumed on August 9.[16]
The fire was directed west towards Newhalem by firefighters using "burnout techniques"; the area near Newhalem includes burn scars from a 2015 wildfire that would slow progress. The strategy was paused after a red flag warning was issued by the National Weather Service for the Diablo area with a high temperature of 104 °F (40 °C) recorded on August 13.[17] Smoke from the fire moved southwest into the Puget Sound region, including Seattle, on August 13 and caused worsened air quality readings.[18] The smoke from the Sourdough Fire and other fires in Washington and British Columbia returned to the Puget Sound region the following week and caused the air quality index in Seattle to reach 190 on August 20, the worst among major cities globally.[19]
The North Cascades Highway reopened on August 23 for through travelers, with stops prohibited and recreation areas remaining closed due to the Sourdough and Blue Lake fires.[20] It closed a day later and was reopened on August 30 for travel with pilot vehicles to direct traffic.[21] The North Cascades Institute cancelled all of their programs for 2023 as a result of the fire, which forced their on-site employees to evacuate from dormitories.[22] Management of the Sourdough Fire was transferred from the Northwest Incident Management Team 8 to the National Park Service on August 29 following successful containment measures.[23] The fire's spread slowed after rainfall in early September as containment reached 25 percent;[24] several campsites and recreation areas in the North Cascades National Park Complex were reopened on September 11 due to improved conditions.[25]
References
edit- ^ a b "Sourdough Fire Update". InciWeb. September 15, 2023. Retrieved September 17, 2023.
- ^ Lerner, Julia (July 31, 2023). "Crews battle Sourdough wildfire in Whatcom County". Cascadia Daily News. Retrieved August 7, 2023.
- ^ "Sourdough Fire Evening Update" (Press release). National Park Service. July 29, 2023. Retrieved August 4, 2023.
- ^ "Sourdough Fire in Whatcom County expands to 2,933 acres, 0% contained". KIRO 7 News. August 4, 2023. Retrieved August 4, 2023.
- ^ a b Bellamy-Walker, Tat (August 5, 2023). "North Cascades highway shut down due to wildfire". The Seattle Times. Retrieved August 6, 2023.
- ^ Mittendorf, Robert (August 7, 2023). "Highway remains closed as Sourdough Fire creeps toward town, power-generating plant". The Bellingham Herald. Retrieved August 7, 2023.
- ^ a b Phair, Vonnai (August 9, 2023). "North Cascades highway reopens as Sourdough fire continues to burn". The Seattle Times. Retrieved August 9, 2023.
- ^ a b Phair, Vonnai (August 11, 2023). "North Cascades Highway closes again as Sourdough fire burns". The Seattle Times. Retrieved August 11, 2023.
- ^ a b Mittendorf, Robert (August 4, 2023). "'We are holding our own': Sourdough Fire grows significantly as evacuations ordered". The Bellingham Herald. Retrieved August 4, 2023.
- ^ "Sourdough Fire Update – August 11, 2023". InciWeb. August 11, 2023. Retrieved August 11, 2023.
- ^ Mittendorf, Robert (August 7, 2023). "Whatcom County wildfire closes major highway, grows overnight to nearly 3K acres". The Bellingham Herald. Retrieved August 7, 2023.
- ^ "Fire burning in the North Cascades creates smoke plume visible from Puget Sound area". KING 5 News. August 4, 2023. Retrieved August 5, 2023.
- ^ a b Ryan, John (August 8, 2023). "Sourdough Fire takes bite out of Seattle's electricity supplies". KUOW. Archived from the original on August 11, 2023. Retrieved August 10, 2023.
- ^ Mittendorf, Robert (August 3, 2023). "Sourdough fire could burn all summer as firefighters defend town, hydroelectric plant". The Bellingham Herald. Retrieved August 4, 2023.
- ^ Strang, Jenn (August 5, 2023). "Seattle City Light providing assistance as Sourdough wildfire continues to grow". Powerlines. Seattle City Light. Archived from the original on August 6, 2023. Retrieved August 6, 2023.
- ^ Ryan, John (August 11, 2023). "Power production resumes at Skagit dams near Sourdough Fire". KUOW. Archived from the original on August 15, 2023. Retrieved August 14, 2023.
- ^ Mittendorf, Robert (August 14, 2023). "Small Whatcom County mountain town, power station out of fire danger as blaze continues". The Bellingham Herald. Retrieved August 14, 2023.
- ^ "'Noticeable smoke' in Seattle area due to Sourdough fire". KING 5 News. August 13, 2023. Archived from the original on August 14, 2023. Retrieved August 14, 2023.
- ^ Phair, Vonnai (August 21, 2023). "As 6 large WA wildfires burn, here's when Seattle-area smoke could clear". The Seattle Times. Archived from the original on August 21, 2023. Retrieved August 22, 2023.
- ^ Phair, Vonnai (August 22, 2023). "North Cascades Highway to reopen as Sourdough, Blue Lake fires burn". The Seattle Times. Retrieved August 24, 2023.
- ^ Zhou, Amanda (August 30, 2023). "North Cascades Highway reopens for travel; 2 fires continue to burn". The Seattle Times. Retrieved August 30, 2023.
- ^ Higashi, Simone (August 25, 2023). "Environmental Learning Center cancels programs for the rest of the year". Cascadia Daily News. Retrieved September 17, 2023.
- ^ "Transfer of Sourdough Fire Command to North Cascades National Park Complex, August 29, 2023". InciWeb. National Wildfire Coordinating Group. August 29, 2023. Retrieved August 30, 2023.
- ^ "Cooler temperatures, rain slow Sourdough Fire". Cascadia Daily News. September 5, 2023. Retrieved September 17, 2023.
- ^ Worley II, Alton (September 11, 2023). "Diablo Lake among trails, camps reopened as Sourdough Fire shows minimal fire behavior". KOMO News. Retrieved September 17, 2023.