Saturday, 20 June 2020, the Bighorn Fire continued to burn. During the morning I could not see the mountain from home. There was a lot of smoke visible in most of the sky from the fire and the extensive backfire operations. Mid-day I participated in a "Thank You First Responders!" sign creation event at the Oracle Visitors Center. The signs were placed along the main street through Oracle that the First Responders travel going to and from the nearby fire operations being done to protect Oracle and the surrounding area. I took this photo of the Oracle Fire Department across the street from the Oracle Visitors Center.

Mid-afternoon on Saturday the sky was still filled with smoke, as seen in these web cam images (clockwise from top: N-E-S-W).

The 1700 MST GEOS-East satellite image showed the smoke from the Bighorn Fire streaming into New Mexico.

This fisheye lens photo was taken about sunset; North is at the top and East at the left. Pretty obvious why I have not been opening the observatory recently.

The Saturday evening fire report said the fire was still at 42,798 acres burned but that the perimeter containment had dropped further to 19%. This photo taken about 45 minutes after sunset shows very few active fires burning, which was quite a significant change from recent nights thanks to the efforts of the firefighters.

Sunday, 21 June, was clear but a blue haze was visible across the valley to the west as the sun rose over the hill. There was a strong smell of smoke. The fire grew to 51,628 acres burned overnight with still 19% perimeter containment. Mid-morning I went to the observatory just to check on things inside. All was OK, as expected. However, I did see six small greyish specks on the black seat cushion of my observing chair. Probably ash from the fire. This was how the sky looked mid-morning.

Towards the mountain


Towards the northeast

Mid-afternoon was not any better, nor at sunset.

The evening fire report still said 51,628 acres burned but the containment dropped even further to 16%. After dark I looked at the mountain with 7x50 binoculars and could see only three small dots of flame. Most of the fire was on the southern side of the mountain.

This map shows the extent and closeness of the fire. The part we can see from home is due south about 10 miles. The closest fire area is about 4 miles southeast of us. That area has been getting a lot of suppression efforts to protect the towns of Oracle and San Manuel. There are over 900 firefighters working the entire fire.

As of Monday morning, 22 June, the Bighorn Fire threat to Oracle was declared to be "very low", although the current 17 June evacuation order on the southeast side of Oracle remained in place and the rest of Oracle (including us) was still in the "be SET to go" order. The fire had burned 58,553 acres (still 16% containment). The sky had much less smoke than in recent days and the view of the mountain was pretty clear, but with smoke from fire on the south side of the mountain. There was still a strong smell of smoke.

By mid-day on Monday thin wispy smoke was visible in all of the sky, as seen here:

Late Monday afternoon the evacuation order that had been in place for part of Oracle since Thursday, 18 June, was lifted. The "be SET to go" order remained in place for all of Oracle. Monday's GEOS-East satellite showed how widespread the smoke was.

The Monday evening fire report said the acreage burned remained at 58,553 acres but the perimeter contained was up to 33%, including increases south of Oracle. The current evacuation status will likely remain at SET for Oracle for several more days as southeast winds are expected to increase later this week and push the fire into unburned areas on the Oracle side of the mountain. Backburning operations will be increasing in those areas. After the briefing ended I checked the mountain using binoculars. Only one small dot of fire could be seen on the side north but the smoke was brightly illuminated by fire east of the Mt Lemmon Observatory.

Tuesday, 23 June, dawned clear and smokey. Overnight the fire continued to grow (a lot) to 65,536 acres burned with 33% containment.

---

I have received some more eyepieces from Explore Scientific to review for Astronomy Technology Today magazine. Unfortunately, getting to use the eyepieces will be delayed until the sky quality improves. The firefighters do not expect the fire conditions to improve until sometime in July when monsoon rains arrive.

In the more Good News category, the replacement POD Zenith Table (PZT) is scheduled to be installed on 23 June.

---

Comments are welcome using Email. Twitter users can use the button below to tweet this report to their followers. Thanks.

Tweet

---

Previous report

Cassiopeia Observatory Home Page