It's a grower, not a shower. That 100 acres was in the first hour. An hour later it had spread 140 more acres and the atmospheric conditions are really bad today. I'm used to the small ones that are likely to fizzle but this has the potential to become a much larger fire over the next week. The Cameron Peak fire just northwest of it was 208k acres in better conditions.

Edit: 864 acres now in the space of 7 hours. The smoke plume is now 30% of the sky while regional reservoirs have Chinook helicopters and tanker planes drawing water to pour on it. Winds are getting sketchy tonight so I'm ready to bug out at a moment's notice if the evac zone keeps growing closer.