Smoke Outlook

Air quality is forecast to range from Good to Unhealthy for Sensitive Groups; however hourly readings may be higher at times.  Most recent monitor observations are currently reading in the Good to Moderate level for an hourly reading.  Yesterday saw levels that ranged from Good to Moderate with Riggins in the Unhealthy for Sensitive Groups for a 24hr AQI.   Conditions have improved dramatically across the state as consistent southwesterly winds provided clearing of smoke at the surface and aloft.

                                                                                                                                             

The upper low pressure system will begin to track to the northeast which will further weaken the upper level ridge currently in place over Idaho.  Surface winds will be from the west-southwest at 2-8 mph with locally northwest winds over portions of the Upper Snake River Plain, Treasure Valley, and Camas Prairie.  Skies will be sunny.  Mixing heights will range from 2,000-8,000 feet AGL across all of Idaho today with poor to marginal ventilation over the entire Snake River Plain and from Weiser south.  Ventilation is also poor to marginal over most of western central Idaho.  Transport winds will be from the west-southwest at 5-10 mph. 

 

Improvement of air quality is expected to continue today with light smoke possible from Boise to Riggins and east through the Salmon River Corridor to Salmon. This evening, regional smoke is expected over the Middle and Upper Snake River Plain; however concentrations will be light in comparison to previous readings.  Tomorrow, expect impacts to be localized to central Idaho, the Big, Little, and Lemhi drainages into the northern periphery of the Upper Snake River Plain.  Lofted smoke is expected to cover the northern Panhandle tomorrow as smoke from fires in Washington become more active today.

Smoke forecasts are dependent on predicted fire growth and weather.  If conditions change unexpectedly, impacts could occur.  When visibility starts to go below 5 miles, sensitive groups should minimize outdoor activities.  Everyone else should minimize prolonged or physical activity outdoors.  

Your eyes are your best tools to determine if it’s safe to be outside. Even if you smell smoke, the air quality may still be good. 

How to estimate air quality based on visibility for areas without an air quality monitor or airport visibility estimate:

a. Face away from the sun.

b. Determine the limit of your visible range by looking for targets at known distances (miles).

c. Visible range is when an object you can easily see in the distance disappears.

d. Use the visibility values above to determine the local wildfire smoke category.

AQI Category	Visibility (miles)
Good	11+
Moderate	6-10
Unhealthy for Sensitive Groups	3-5
Unhealthy	1½  -2¾
Very Unhealthy	1-1¼
Hazardous	Less than 1