Current as of

7/15/2022, 6:57:46 PM

Incident Type

Wildfire

Cause

Under Investigation

Location

Southern portion of Yosemite National Park;

Incident Commander

Josh Boehm, California Interagency Incident Management Team 13.

Incident Description

Full Suppression.

Coordinates

37.499 latitude, -119.614 longitude

Total Personnel

1,623

Size

4,779 Acres

Percent of Perimeter Contained

35%

Fuels Involved

Very heavy accumulations of available dead surface fuels with ample snags, downed timber, and concentrations in an old-growth forest condition. Representative fuels include large timber with an understory of young conifer and shrubs. Very deep duff and accumulation of timber litter (branchwood and needles) dominate the forest floor. Recent large fire scars in the area include woody fuels and recent shrub growth. Live fuels (shrubs/brush) are seasonally moist and are providing limited intensity and spread.

Significant Events

A persistent weather pattern for the next several days will support active-to-very active fire behavior in heavy dead and down fuels. Expect afternoon episodes of group torching, short crown runs, and spotting primarily on the south side of the S. Fk. Merced River and upstream toward Iron Creek. Continued warming and drying over the next several days will bring additional fire growth and smoke production where control lines have yet to be constructed.

Planned Actions

Continue to secure and reinforce the Hwy 41 corridor, Mariposa Grove Rd., and continue to construct handline and dozer line from Wawona Point to the west and north to South Fork of the Merced River. Protect remote cabins within Yosemite National Park and Sierra National Forest.

Projected Incident Activity

12 hours: Persistent warm and dry conditions continue to produce active-to-very active fire behavior during the day, that extends into the night due to poor relative humidity. Significant activity was observed on the east flank of the fire south of the S. Fk. Merced River near Iron Creek including group torching and short crown runs on steep slopes. Up canyon wind flow is producing sustained backing on slopes, flanking, and torching with spotting as the fire progresses up the South Fork Merced River drainage. Downslope and down drainage wind flow will continue to provide smoke accumulation in the valleys during the night under a strong inversion, while south-southwest winds at higher elevations remain relatively clear.

24 hours: Continuing warm and dry conditions will provide sustained active fire behavior throughout the period, with the burning conditions extending well into the night due to poor relative humidity recovery on higher terrain. Generally light winds will provide sustained backing on slopes with flanking, torching, and spotting, ridgetop winds will provide clear sky and good ventilation. Continued fire spread may be expected on the east flank of the fire in the South Fork Merced River drainage in the Iron Creek area. Potential for spotting north of the South Fork Merced River in the Johnson Creek area as the fire backs to the bottom of the slope.

48 hours: Warm and dry conditions combined with poor-fair nighttime relative humidity will produce conditions for active to very active fire behavior on uncontained portions of the fire perimeter. Expect sustained backing, active flanking, with frequent torching with spotting, and short headfire runs in the South Fork Merced River drainage as the fire spreads to the east.

72 hours: Continued warming and drying will maintain active to very active fire behavior potential. Likely increase in fire behavior to include group torching, short torching/crown runs on wind aligned slopes, and spotting to .5 miles. Smoke will be visible in the late afternoon with southwesterly transport wind. Nighttime cooling will allow smoke to accumulate in the valleys due to downslope flow and a strong inversion.

Anticipated after 72 hours: The persistent pattern of warm and dry conditions will continue with very little change overall. Conditions will be present to provide active to very active fire behavior on uncontained portions of the fire.

Weather Concerns

Persistent high pressure over the region will continue to produce warm and dry conditions during the day and mild temperatures with moderate humidity recovery at night. The prevailing winds will be out of the southwest, but most of the fireline will be impacted by terrain driven flow. Elevations above 7500 feet on the eastside of the fire will see gusts between 20 and 25 mph.

Observed Weather Conditions July 15, 2022: Wind Speed / Max. Gust Sustained 3-7 mph gusts to 16 mph. Temp Highs 84-91 Direction Southwest RH 18-26%

Forecasted Weather for Next Operational Period July 16, 2022: Wind Speed / Max. Gust Sustained 3-7 mph gusts to 15 mph. Temp Highs 85-92 Direction Southwest RH 17-25%