[Yosemitest]

Something else of interest:

FlightAware said visibility was about 6 miles amid mist and a layer of broken clouds at 700 feet above the ground.

Now the Weather minimums on the LOC RWY 18 Approach Plate are above what Bloomberg says that FlightAware said:
Weather Minimums for the Localizer Runway 18 Apoporoach are as follows: Category A or B pilots/aircraft:

1,380 foot ceiling or above, and at least 1 Mile visibility

When using IMTOY Fix Mimimums
1,200 foot ceiling or above, and at least 1 mile visibility

Category C or D pilots/aircraft:

1,380 foot ceiling or above, and at least 2 Mile visibility

When using IMTOY Fix Mimimums
1,200 foot ceiling or above, and at least 1-5/8 mile visibility

That's a greater requirement than the CEILING Broken Clouds at 700 feet.
That's another RED FLAG!

[merkator]

Here is the actual weather observation (METAR) from ADDS. This was the official observation at the time of the accident.

KBHM 140953Z 34004KT 10SM FEW011 BKN035 OVC075 23/22 A2997 RMK AO2 SLP141 T02330222

The ceiling was 3,500 feet and one at 7,500 feet. Few at 1,100 feet does not constitute a ceiling.