Increased smoke production and transport expected tomorrow

Air quality forecasts for today are in the Good to Unhealthy for Sensitive Groups Category.

Today, the upper-level ridge will shift slightly east in response to an upper-level disturbance approaching from the southwest. Cloud cover and smoke aloft will keep temperatures suppressed slightly over southern Idaho. There will be a chance for isolated thunderstorms over southern Idaho along the ID/NV border. Surface winds will be from the northwest to northeast. Surface wind speeds will be from 2-8 mph today. The strength and positioning of the ridge of high pressure will limit smoke transport but keep activity high. Conditions will change considerably tomorrow with a pattern change and the upper-level low pressure system tracking over Idaho. Expect increased fire activity and increased smoke production and transport.

Smoke will continue to affect the Central Idaho Mountains the greatest today with high concentrations in Lemhi County, over the intersection of Custer, Valley, and Boise Counties, Valley, and Adams Counties. Elevated smoke concentrations will develop over the northern Panhandle from the Canadian border and south to Kootenai County. Smoke in Central Idaho will begin to expand in coverage north to Benewah County, south to Payette County, and west to the Oregon border by tomorrow morning. Late in the forecast window, widespread smoke covers the northern 2/3rds of the state with increased coverage and concentrations after that period.

HRRR-Smoke Vertically Integrated Smoke initialized 12Z (06am MDT) indicates increasing smoke coverage and locally high levels of concentrations in the vicinity of fires.  This coverage and concentration expand tomorrow and so expansive deterioration should be anticipated.