Current as of

7/20/2022, 6:32:52 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

1,330

Size

4,856 Acres

Percent of Perimeter Contained

58%

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

Active, Flanking, Backing, Creeping.

Successful suppression actions have resulted in diminished fire behavior on all portions of the fire. The fire continues to burn in heavy dead and down timber fuels on the eastern portion of the fire within constructed lines. A very persistent warm and dry weather pattern continues to support the potential of active-to-very active fire behavior today. Primary area of fire behavior focus includes the S. Fk. Merced River upstream to the Iron Cr. and Johnson Cr. areas where most of the current activity is occurring. Progressive heat loss, with length of time since burning, combined with the aggressive mop-up that will be occurring will provide additional security to fire lines.

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: Minimal fire spread was observed on the east flank of the fire south of the S. Fork. Merced River near Iron Creek that included flare-ups, and continued consumption of heavy fuels on steep slopes. Very persistent warm and dry weather continues to produce pockets of interior active fire behavior, that will extend into the evening due to low relative humidity. Downslope and down drainage wind flow will continue to provide diminishing 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 produce the potential for active fire behavior during the period, with the burning conditions extending into the evening due to poor relative humidity recovery on higher terrain. Generally light winds will produce pockets of isolated backing on slopes with flanking, and isolated torching within the control lines. 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 area, and across Iron Cr. to the east as the fire consumes residual fuels near the containment lines.

48 hours: Warm and dry conditions combined with poor-fair nighttime relative humidity will maintain the potential of active to very active fire behavior. Expect isolated interior pockets of fuel consumption through creeping, smoldering, with occasional flare-ups. Diminishing heat sources, aggressive mop-up, and time since burning will provide additional security to prevent escape from control lines.

72 hours: Persistent warm and dry weather pattern will maintain the potential for active to very active fire behavior. Expect a continued significant reduction in fire activity due to successful suppression activities and diminishing heat from fewer sources. Minimal 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 continues with very little change overall. Conditions will be present that provide the potential for active to very active fire behavior, but with diminishing heat sources and successful suppression efforts the threat of spread or escape will be minimized.

Weather Concerns

Synopsis: High pressure will produce another warm and dry day across the fire area. 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 some gusts up to 20 mph.

Observed Weather Conditions July 20, 2022: Wind Speed / Max. Gust Sustained 3-7 mph gusts to 17 mph. Temp Highs 8 1-90 Direction West-southwest RH 19-29%

Forecasted Weather for Next Operational Period July 21, 2022: Wind Speed / Max. Gust Sustained 4-8 mph gusts to 18 mph. Temp Highs 82-91 Direction West-southwest RH 17-27%