SALT LAKE CITY — It’s starting to get a bit smoky across northern Utah and it’s not at all because of the handful of active wildfires currently burning across the state.
It’s instead largely a result of many wildfires currently burning hundreds of thousands of acres across California and Nevada. The largest of those is the SCU Lightning Complex Fire just east of California’s Bay Area, which had burned more than 137,000 acres as of Thursday afternoon since lightning ignited it on Tuesday. It’s just 5% contained, according to Cal Fire.
The National Weather Service tweeted that smoke from the fires started making its way east into Utah on Thursday afternoon. A thin level of smoke became noticeable across the Wasatch Front at the time with air quality across KSL Weather’s Air Quality Network moving into the moderate range.
By Thursday evening into Friday morning, the smoke was much more noticeable. The weather service radar showed the heaviest smoke in Utah was centered around northwest part of the state Friday morning.
At noon Friday, visibility dropped to 3 to 8 miles across parts of the Wasatch Front into the Cache Valley, according to KSL meteorologist Dan Guthrie. Air quality levels in some areas also reached "unhealthy" levels for some places in those areas.
Heavier smoke from the fires moving across southeast Oregon into Idaho.
KSL meteorologist Kevin Eubank said Thursday evening that the smoke will likely linger across most of Utah for a couple of days, possibly into Sunday.
So what’s causing the smoke from outside states to waft into Utah? It’s simply due to air pressure systems at work. Eubank explains that the high-pressure system that helped create another round of record-breaking heat across Utah the last few days continues to move south and as it does, it allows airflow from the west to move back through the state.
“Air quality has already deteriorated to moderate levels almost everywhere,” he said. “Unlike in a valley inversion where the low valleys see the worst pollution, when you’re dealing with smoke, the smoke comes from the upper-level air. That smoke gets filtered all the way into Logan and the Cache Valley, Heber Valley and over the mountains. It’s really a valley problem.”
He added the flow of smoke into the state is expected to continue until the next high-pressure system moves into place to alter airflow, which appears to likely be sometime Sunday morning.
Air quality levels are likely to be moderate to unhealthy for sensitive groups until then. In fact, the Wasatch Front counties have forecasts in the “orange” unhealthy for sensitive groups Friday and Saturday, according to the Utah Division of Air Quality.
Eubank noted that the sun and ozone in the heat of the day are creating a “one-two punch" for Wasatch Front areas. He advised those with asthma or other breathing conditions to stay indoors if possible because of the air quality the next few days. He also pointed out smoke levels, much like ozone and heat, are less noticeable in the morning and evening hours.
“If you’re going to go out and exercise, earlier in the mornings, later in the evenings tend to be better for you versus the heat of the day and the peak of what air quality would be as well as the ozone,” he said.
Visit the KSL Weather Center for more forecasts across Utah over the next seven days. You can also check out the KSL Air Quality Network to find current air quality conditions and air quality forecast across many parts of the state.