Current as of

7/18/2022, 6:38:40 PM

Incident Type

Wildfire

Cause

Under Investigation

Location

Southern portion of Yosemite National Park; Sierra National Forest.

Incident Commander

Mike Wakoski, California Interagency Incident Management Team 13.

Incident Description

Full Suppression.

Coordinates

37.499 latitude, -119.614 longitude

Total Personnel

1,579

Size

4,911 Acres

Percent of Perimeter Contained

51%

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

Continued persistent weather pattern of warm and dry conditions supports the potential of active-to very active fire behavior for the next several days. The fire continues to burn in heavy dead and down timber fuels. Observed fire behavior has been diminished by successful suppression activities on most portions of the fire. Primary area of concern for fire behavior includes the S. Fk. Merced River upstream to the Iron Cr. and Johnson Cr. areas where most of the current activity is occurring. Continued warm and dry weather may contribute to 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. Continue to construct handline where possible in the Iron Creek drainage area. Continue contingency line construction south of the incident.

Projected Incident Activity

12 hours: Very persistent warm and dry weather continues to produce pockets of active-to-very active fire behavior during the day, that extends into the night due to poor relative humidity. Minimal fire spread was observed on the east flank of the fire south of the S. Fk. Merced River near Iron Creek including torching, flanking, and backing on steep slopes. Downslope and down drainage wind flow will continue to provide smoke accumulation in the valleys during the night under a strong inversion, while southwest winds at higher elevations retain a relatively clear sky.

24 hours: Continuation of warm/dry weather will provide active fire behavior conditions 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 produce sustained backing on slopes with flanking, torching, and spotting in the Iron Cr. area; southwesterly ridgetop winds will provide clear sky and good ventilation. Continued potential for spotting north of the South Fork Merced River in the Johnson Creek, and across Iron Cr. to the east 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 torching with spotting as the fire consumes pockets of unburned fuel in the South Fork Merced River drainage.

72 hours: Continued warm and dry conditions will maintain the potential for active to very active fire behavior. Expect a significant reduction in fire activity due to successful suppression activities. 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 the potential of active to very active fire behavior on unlined portions of the fire.

Weather Concerns

Synopsis: Warm and dry conditions will continue due high pressure situated over the Four Corners region. The prevailing winds will be out of the west-southwest, but most of the fireline will continue to be impacted by light, terrain-driven winds becoming upslope/upcanyon in the afternoon. Elevations above 7500 feet will see gusts up to 20 mph.

Observed Weather Conditions July 18, 2022: Wind Speed / Max. Gust Sustained 4-8 mph gusts to 20 mph. Temp Highs 80-89 Direction West-southwest RH 20-30%

Forecasted Weather for Next Operational Period July 19, 2022: Wind Speed / Max. Gust Sustained 3-7 mph gusts to 18 mph. Temp Highs 79-88 Direction West-southwest RH 20-30%s of the fire.