Bobcat Fire prompts evacuation of Mt. Wilson in southern California

Santa Ana winds predicted for Tuesday could cause the fire to endanger structures in foothill communities. Evacuation warnings have been issued.

Updated September 8, 2020  |  10:07 a.m. PDT

map of the Bobcat Fire
3-D map of the Bobcat Fire looking north at 11:29 p.m. PDT September 7, 2020.

The Bobcat Fire in the Angeles National Forest north of Monrovia and Duarte in southern California grew on Monday to 8,553 acres.

Evacuation warnings (be ready to evacuate if necessary) have been issued for some communities in the foothills.

map of the Bobcat Fire
3-D map of the Bobcat Fire looking west at 11:29 p.m. PDT September 7, 2020.

The weather forecast predicts strong northeast winds which could cause the fire to spread much more quickly.  The strongest winds are expected Tuesday night and Wednesday morning with gusts between 35 and 55 mph with isolated gusts around 60 mph. Relative humidity will drop into the teens and single digits Tuesday afternoon with little or no recovery (or increase) Tuesday night and Wednesday.

(To see all articles on Wildfire Today about the Bobcat Fire, including the most recent, click HERE.)

A Red Flag Warning is in effect Tuesday through Wednesday for all areas of Ventura and Los Angeles counties, except for the Antelope Valley.


September 7, 2020 | 8:14 p.m. PDT

map Bobcat Fire
Official map of the Bobcat Fire at 4:30 a.m. PDT Sept 7, 2020. Produced by the Angeles National Forest.

The Bobcat Fire that started in a canyon north of the Los Angeles area has spread south to the ridgetop above the Los Angeles basin cities of Monrovia and Duarte, prompting the evacuation of the Mt. Wilson Observatory and multiple campgrounds. Fire authorities said Monday morning the fire had burned 4,871 acres.

The weather forecast for Santa Ana winds on Tuesday and Wednesday is troubling, and predicts 20 mph northeast winds gusting to 35 mph at the higher elevations beginning by noon Tuesday. The forecast is unclear about the winds in the lower elevations, but strong northeast winds could cause the spread of the Bobcat Fire to increase. It is likely, a meteorologist said, that a Red Flag Warning will be issued for Tuesday and Wednesday.

Kris Ankarlo, a reporter for KFIAM640, said fire authorities warned in a Monday afternoon press conference that foothill communities should plan for possible evacuation if the Santa Winds align with the foothill canyons and push the fire into the wildland-urban interface.

The blaze started with a rapid rate of spread on September 6 at 12:21 p.m. near the Cogswell Dam and West Fork Day Use area in heavy fuels.

Monday morning the resources assigned included 5 engines, 3 hand crews, 4 helicopters, 5 fixed-wing aircraft, and 2 water tenders for a total of 101 personnel. For a wildfire in southern California with tremendous potential, these numbers are a very small fraction of what you would normally see on the second day, and speaks to the serious competition for resources needed to combat the fires in California.

Bobcat Fire
APPROXIMATE LOCATION of the Bobcat Fire. Looking west toward the Pacific Ocean 1:42 p.m. PDT September 7, 2020. Do not use to make evacuation or any other decisions. The map is based on heat detections from satellites.

Smoke in the area Monday afternoon likely made it difficult to operate firefighting aircraft, including air tankers and helicopters.

Bobcat Fire
The Bobcat Fire. Looking east from Mt. Wilson at 5:29 p.m. PDT September 7, 2020. The iconic observatories can be seen in the foreground.

In an action that has not occurred in recent memory, based on fire and weather conditions the U.S. Forest Service ordered the closure of seven National Forests in California: Angeles, San Bernardino, Cleveland, Los Padres, Inyo, Sequoia, Sierra, and Stanislaus.

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Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

5 thoughts on “Bobcat Fire prompts evacuation of Mt. Wilson in southern California”

  1. Could fire reach Clairmont and Upland in a few days, with strong Santa Ana winds. What are your predictions? Thank You John

    1. That’s what I was wondering. Given the north & south layout stretch of the fire map above which is really quite a long lengthy distance and the further spot fire dots on the map, if this Santa Ana Wind advisory does materialize, it sets up a bad scenario for south and west movement. Lot’s of chaparral and steep canyon real estate there.

  2. Management will be assumed by Eastern Area Silver Team today you missed that important part Bill.


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