Some shots of the Bobcat Fire while away from the house
The wind has shifted and the smoke in the atmosphere isn’t as suffocating as it has been until this morning. I still can’t see the Bobcat fire from the house by looking up at the mountain, but it’s apparently very close to Mt. Wilson and the closest part of the fireline is about 3 miles from the house. Things generally aren’t looking good. I suspect we may see flames before the evening is out.
Read a tweet (Twitter)
Read Bobcat Fire: Now More Than 19K Acres, Evacuation Warnings Remain In Place For Foothill Communities (LAist)
The brush fire erupted near the Cogswell Dam and then spread rapidly amid an intense, record-breaking heat wave, prompting evacuation orders for Mt. Wilson Observatory.
Still growing in size, but fortunately not toward high population zones at the moment.
Annotated Bobcat Fire Update (City of Arcadia)
***Update as of 9/9/2020 @ 4:51 PM***Voluntary evacuations lifted for residents north of Foothill Blvd. and east of Santa Anita Ave. The Bobcat Fire has generally progressed away from the City of Arcadia.  The current weather forecast suggests that Santa Ana winds will dissipate this evening and the Red Flag Warning will be removed after 8:00 p.m.Based on these factors, the City of Arcadia is removing the recommendation for residents to evacuate.  However, residents are advised to remain on alert for any changes to weather conditions that may affect the fire.  Evacuations may be necessary for your safety if conditions change. 
This is a particularly good sign!

Replied to a tweet (Twitter)
I’m sure there was a similar peak in 2009 for the Station Fire. I remember seeing the pyrocumulus cloud in Glendale/Pasadena all the way down to San Diego.

It’s also the last time that Mt. Wilson was threatened, though tonight it’s from the East side of the mountain. I’m watching closely because I’m 8 miles from the Bobcat Fire to the East and we’re under an evacuation warning. Fortunately the live cam has some reasonably clear footage of the immediate danger as the observatory is 4 miles up the hill above us.

Night photo of flames burning near the Mt. Wilson Observatory.
Mount Wilson Observatory live cam facing east toward the Bobcat Fire at 12:40 AM PST
Read Monrovia, Duarte On Alert As Bobcat Fire Continues Its Rapid Growth (CBSLA / KCAL 9)
With powerful Santa Ana winds expected to create challenges for firefighters Tuesday, the Bobcat Fire burning in the Angeles National Forest north of Monrovia nearly doubled in size for the second straight day. The Bobcat Fire has burned 10,344 acres and still had zero containment as of 10 p.m. Tuesday, according to the U.S. Forest Service. The fire is churning through some vegetation and brush which has not burned in more 60 years. “The canyons that this fire has lined up with — Monrovia Canyon, Santa Anita Canyon, Little Santa Anita Canyon — those canyons have not burned since 1957 in the Monrovia Peak Fire,” Angeles National Forest Chief Robert Garcia said Monday.
Nothing really very new here.
Liked a tweet (Twitter)
This seems to be the first official resource with details about the evacuation warning. Sad that none of the local news, fire, or government sources on Twitter have got this sooner.

Event the local Altadena Sheriff’s station had little detail on a phone call. (I’m sure they got swamped.)

Read Bobcat Fire: Arcadia Warns Of Possible Evacuations As Blaze Surpasses 10,000 Acres (LAist)
The Bobcat fire ignited on Sunday and quickly grew to threaten Mount Wilson.
We’ve just gotten an evacuation warning, so I’m searching around a bit to find sources to back up the text that disappeared. So far there’s nothing in the media, and it may take a half an hour or more to find more details.  This is the only recent story online at the moment and there are a few spurious tweets that cover Altadena in the warning, but those are entirely unsourced.

Phone notifications that disappear too quickly in emergencies can be really bad UI.

Bobcat Fire update
I’m just South and slightly West of the Wilson Observatory which is at the top of the mountain just above our house. Fortunately we’re not in any of the preliminary evacuation zones which are all immediately South of the fire. We won’t really need to worry heavily unless it gets closer to the observatory.

View from the Mount Wilson Observatory East towards the burning flames of the Bobcat Fire
View from the Mount Wilson Observatory facing east toward the fire at 9:00 PM on September 7th.
Topological map of the Bobcat fire in the Angeles National Forest
The Bobcat fire coverage as of about 11:30 AM this morning. (Courtesy of the Angeles National Forest)