There was a small chance that thunderstorms developing over the Owyhees Monday afternoon could push out some of the smoke from two giant wildfires burning east of Boise and brings showers to the Valley but don't count on it.
"I'm forecasting the smoke to stay. I just don't see any strong winds," said National Weather Service meteorologist Dave Groenert, looking ahead to Friday.
A multitude of lighting strikes Thursday night caused numerous fires east of Boise. Those fires merged into two giant fires, the Elk Complex and Pony Complex fires. The fires are burning on both sides of the South Fork of the Boise River.
Daily wind patterns and overnight inversions have left the Treasure Valley socked in with wildfire smoke, a repeat of smoky conditions from last summer's Trinity Fire. Conditions are much worse in the mountain communities of Atlanta and Lowman, which had air qualities in the red alert "unhealthy" range Sunday.
On Monday, numerous communities were expected to have periods in the unhealthy range, including Idaho City, Lowman, Atlanta, Challis, and Ketchum, according to the Idaho Department of Environmental Quality. The Idaho Department of Health issued an advisory Monday afternoon, urging the public to limit outdoor activity.
The Idaho Department of Environmental Quality said Tuesday's air quality is expected to be orange, or unhealthy for sensitive groups, in the Treasure Valley. That means people with lung disease, children, older adults and people active outdoors are at most risk. The DEQ said people should consider postponing strenuous activities until air quality improves.
The smoke filters into the Treasure Valley on southeast winds overnight, and the pollution gets trapped near the ground with colder air. Northwest winds typically kick in during the late morning or early afternoon, and if strong enough can push out polluted air.
But northwest winds weren't strong enough Monday to make much impact. Winds were light, ranging from 5 to 10 mph in the afternoon. The smoke is filtering the sun's rays, keeping the temperature below 90 Monday. If the smoke remains at the same density, the temperatures could stay in the upper-80s all week.
A yellow air quality alert is in effect, and outdoor burning is banned in Ada and Canyon counties, and all of the cities within those counties.
On Monday, the Idaho Department of Environmental Quality issued a stage 1 advisory for Boise and Elmore counties, meaning all open burning is banned in Boise and Elmore counties. The ban is in effect until 3 p.m. Tuesday. Read more about wildfire smoke and its health impacts here.