Fire Update 10/24/2017

Last week, we experienced a strong stable air mass over the area bringing warmer than normal temperatures and lower humidity. This contributed to more fire activity and more smoke production as the Empire fire moved through some heavier fuels. The smoke has been flowing into Yosemite Valley and is unable to lift out due to the stagnation. We had a brief respite on Friday and Saturday, but this pattern is expected to return and may continue throughout the week. There is potential for periods of heavier smoke to occur during certain times in Yosemite Valley throughout this period. Dense smoke can aggravate symptoms for sensitive persons and activity should be reduced or avoided.

There are multiple fires burning in Yosemite National Park's wilderness. Fire Managers are working with the local Air Quality Districts and will be monitoring smoke impacts to the park and local communities.

Empire
Discovered: 7/31/17
Location: 1 mile east of Yosemite Ski and Snowboard Area and 3/4 mile south of Glacier Point Road
Size: 8,094 acres
Cause: Lightning
Containment: 85%
Fuels: Red fir
Moving east deeper into the wilderness. Burning into the old “Meadow Fire” footprint in the Illilouette drainage producing moderate smoke. This area has shrubs and heavier dead and down fuel. The trajectory of the fire will likely take it in the direction of sparser fuels later in the week, which should reduce smoke production.
Visible from vistas along the Glacier Point road

South Fork
Discovered: 8/13/17
Location: .75 miles east of the community of Wawona
Size: 7,564 acres
Cause: Lightning
Containment: 90%
Fuels: Mixed conifer and red fir
Fire remains quiet near the community of Wawona on the west and south flank of the fire. Sections of the north flank and the entire east flank are continuing to burn in the wilderness Fire activity has been minimal this week.

Starr King
Discovered: 8/2/17
Location: N 37° 42.965' x W 119° 29.588' at approximately 7800 feet elevation
Size: 70 acres
Cause: Lightning
Spread Potential: Low/ Moderate
Fuels: Red fir/ Lodgepole
Strategy: Monitor
Visible from the Glacier Point Road.

Porcupine
Discovered: 8/2/17
Location: N 37° 49.336' x W 119° 34.720' at approximately 8154 feet elevation off Tioga road.
Size: 9 acres
Cause: Lightning
Spread Potential: Low
Fuels: creeping: burning in duff and dead and down in Lodgepole/Red fir
Strategy: Monitor
Visible burning next to the Tioga road.

Ribbon
Discovered: 9/26/17
Location: 37 45.3 by119 38.5 at approximately 8154 feet elevation off Tioga road.
Size: 2 Acres
Cause: Lightning
Spread Potential: Low
Fuels: Low brush
Strategy: Monitor
Visible from Sentinel Dome and Glacier Point ​

These fires are burning in designated Wilderness. Lightning ignited fires In Wilderness are often allowed to burn if they do not threaten developed areas. The Yosemite Wilderness is a fire adapted ecosystem where past fire suppression has resulted in unnaturally high fuel levels. Allowing fires to burn unimpeded produces a healthier, more diverse forest and helps reduce the severity of future fires.
Updates will be issued on Fridays.