Although the air has cleared somewhat since the big winter storm last week, Mammoth and Mono County residents are still waking up to hazy skies, something relatively unusual for this time of year.
It’s due to two main factors: a strong high pressure ridge, or stable air mass, hanging over the area, and smoke from the still-burning Sheep Fire and some pollution coming from down south.
“Although the Sheep Fire is mostly out, it’s still putting out some smoke and it’s blowing directly toward us,” said Jon Becknell, an air quality specialist for the local Great Basin district.
The high pressure ridge is expected to hold up until Friday, then soften slightly, then return again next week, meaning there won’t be much air movement to kick smoke and pollution out of the area, according to National Weather Service reports this week.
And it might not get a lot better soon.
Although Great Basin Unified Air Pollution Control District has put a moratorium on allowing naturally-caused fires, like the Sheep Fire, to burn without immediate suppression for the rest of the season, local land managers will still be allowed to do some carefully designed prescribed burning, Becknell said.
“They will be allowed to do burns that they begin and complete on the same day, and under a certain number of acres,” he said.
The air pollution control district will also make sure the fires meet a pre-set smoke management plan, and that they do not occur on residential “no-burn” days.