August 4, 2020 | 8:35 a.m. PDT
The growth of the Apple Fire north of Beaumont and Banning in southern California slowed Monday. It chewed through approximately 1,000 more acres primarily on the east side across the head of the Mill Creek Canyon and east into the San Gorgonio Wilderness. The vegetation it is moving into is sparse in some areas, especially in the higher elevations at 8,000 to 11,00o feet. Monday evening the incident management team reported 26,850 acres burned, but that number could be adjusted after they consult the mapping flight conducted at 9 p.m. Monday.
Investigators have concluded the fire was caused by hot carbon particles from the exhaust system of a diesel-powered truck, which is not an uncommon cause of vegetation fires along roadways. All internal combustion engines emit carbon particles and is why spark arrestors are required on chain saws, for example. Carbon particles from diesel engines can be much larger than particles from small engines or those powered by gasoline, and may exceed one inch. Witnesses corroborated the investigators findings. At least three ignition points were found which all merged into one fire.
Damage assessment teams are deployed and will be surveying the fire area for damage to structures and infrastructure.
Evacuation information for Riverside County Residents can be found at www.rivcoready.org/ActiveEvents.
In San Bernardino County, the community of Oak Glen is under an evacuation order. Forest Falls, Pioneertown, and Rim Rock are all under an evacuation warning.
This is why at Wildfire Today we do not repeat the containment percentages given out by fire officials. From NBCLosAngeles today:
Earlier Sunday morning, fire officials said progress had been made and the blaze was 12% contained. However in a later update after U.S. Forest Service took over command, fire officials said the blaze was 0% contained.
On Sunday thousands of people had been busting their asses on the fire for three days, and the U.S. Forest Service basically said not a single foot of fire perimeter had a good fireline.
Resources on the Apple Fire Monday included 31 hand crews, 321 fire engines, 28 dozers, 12 helicopters, 2 small fixed wing planes, 50 water tenders, and a variable number of air tankers for a total of 2,565 personnel.
Originally published August 3, 2020 | 11:31 a.m. PDT
The Apple fire burned actively Sunday, primarily to the north and east. Much of the fire activity is being driven by the record low moisture content of the vegetation in the area combined with high temperatures and low relative humidity. These conditions are contributing to active fire behavior both day and night.
The fire started July 31 near Cherry Valley, California and is spreading north of Beaumont and Banning.
(To see all articles on Wildfire Today about the Apple Fire, including the most recent, click here.)
A mapping flight Sunday evening at 7:45 determined that the fire had burned 24,830 acres, an increase of about 10,000 acres in 24 hours. At about 11 a.m. the incident management team announced it had grown to 26,450 acres.
Sunday night and early Monday morning the fire was very active. Multiple spot fires ignited on the north side which were attacked by a night-vision equipped helicopter. Two of the spot fires were caught but one grew significantly and will be assessed.
The Apple fire is burning in an area with no recent fire history. It is expected to burn into less dense fuels as it progresses. Firefighters on the ground and in the air are building fireline directly on the fire’s edge where possible and are protecting structures in local communities. The extremely steep slopes and elevations up to 11,000 feet make this a challenging assignment for firefighters.
Evacuation information for Riverside County residents is available at the county website where residents can enter an address to see if they are in an evacuation area.
In San Bernardino County, the community of Oak Glen is under an evacuation order. Forest Falls, Pioneer Town, and Rim Rock are all under an evacuation warning.
The weather forecast for Monday calls for more of the same conditions that have led to rapid growth of the fire — 91 to 96 degrees, 15 to 20 percent relative humidity, and ridgetop winds out of the west at 20 mph.
It is difficult for meteorologists to create a forecast for a fire like this. It is on very steep topography that ranges from 3,400 feet at Cherry Valley to 11,503 feet at the top of Mount San Gorgonio.