Regional and local fires pumping out smoke

Air quality today is forecast to be in the GOOD to UNHEALTHY range.

Today, all of Idaho will remain under the persistent upper-level high pressure ridge, which will start to break down on Wednesday as a low-pressure trough approaches. Winds will be easterly in the morning and from the northwest to southwest at 5-10 mph in the afternoon over south Idaho. Over north Idaho, winds will be easterly in the morning and from the southwest to north-northwest at 2-8 mph in the afternoon. Winds in the vicinity of Grangeville will remain northeasterly in the afternoon. The Idaho Panhandle is under a Red Flag Warning starting at 8 am PDT/9 am PDT Wednesday. Central Idaho is under a Red Flag Warning starting at 11 am PDT/12noon MDT Wednesday. Gusty winds and low relative humidity are expected, and thunderstorm chances increase Wednesday with the approaching trough, especially over central Idaho. 

Numerous regional and local fires are impacting air quality. Smoke from just over the Oregon border is being transported into Idaho while the Four Corners fire is adding to the overall impact. On the eastern side of the state, the persistent high-pressure ridge is continuing to limit smoke dispersion while increasing ground settling. Expect overnight smoke impacts in most low-lying mountain valleys, especially over central Idaho. The incoming trough tomorrow may help to disperse smoke and provide some improvement; however, critical fire weather conditions are expected, which could lead to extreme fire behavior and increased smoke production immediately downwind of the fires.  

HRRR-Smoke Near Surface Smoke model initialized at 12Z (06am MDT) shows smoke and haze over the majority of the state with heavy impacts near and immediately downwind of active fires.