Friday, September 11, 2015 - Tenaya Fire Timelapse and Yosemite smoke update for the weekend.

Yosemite air quality monitoring staff were using a time-lapse camera  (not web connected) to monitor smoke from the Rough and the Middle fire when the Tenaya Fire started.  Here's the footage, looking north across the Yosemite Valley toward the smoke.

Hourly concentrations reached the Hazardous range for several hours overnight last night, and are likely to do so again tonight and tomorrow night (Saturday night, 9/12). By afternoon however concentrations were at least briefly in the moderate range, though with currently increasing fire activity there may be little respite.  A change in the pattern starts Sunday night, but smoke from the Butte fire to the north may also be influencing Yosemite by that time.