UDPATE 4/19 — Here is our latest for today, April 19:
UPDATE 1:10 p.m. — Here are a few pictures from about 1 a.m. of the fire from the fire cams:


UPDATE 9:10 p.m. — New information from the fire is scare. Cal Fire is still reporting it at 50 acres and 0% contained, but substantial new information is not likely until morning.
Here is a map of hotspots detected by satellites orbiting the earth in space. That shows the rough area where the fire is burning:

UPDATE 7:40 p.m. — Cal Fire is confirming that the fire has grown to 50 acres, though fire activity is dying down as the sunsets and wind calms. The fire is in the 9000 block of the 253, roughly equidistant from Ukiah and Boonville. It is far from any town, and does not pose a threat to either Boonville or Ukiah. We do not know if there are any structures threatened at this time. The fire is officially zero percent contained, but the rate of spread is not aggressive.
ORIGINAL
MENDOCINO Co., 4/18/21 — A small wildfire is burning in very steep and rugged country off SR-253, between Ukiah and Boonville. The fire had a moderate rate of spread, but with the sun setting and winds dying down the rate of spread is now slow, and firefighters are getting a handle on it. Some PG&E powerlines in the area had to be de-energized, as they were threatened, but there is no confirmation at this time of the cause of the fire. The fire is being called the Turnout Incident.
An exact size for the fire is not available, as it is burning in rugged country, but the fire is not a spot fire, nor is it an escaped burn.
The Howard Forest Cal Fire station duty chief noted that this is the first substantial wildfire of the season in Mendocino County. He also pointed out that the standard coastal winds were blowing later than usual, and that this is of course very early in the season. It was also unusually warm and dry today, with Ukiah hitting a relatively humidity (rH) of 13, conditions which make fire spread much more likely:
Sacramento and Santa Rosa even hit record high temps for the day: