08/03/2015 Idaho DEQ Smoke Forecast

Updated 1030am MDT Monday, August 03, 2015

Valid through Noon MDT Tuesday, August 04, 2015

Smoke Outlook

Air quality is forecast to remain in the Moderate to Unhealthy for Sensitive Groups air quality category across the northern Panhandle with short term readings in the Clearwater drainages and across the Idaho Panhandle.  Impacts are from regional fire burning in primarily in Washington State.  Due to wildfire smoke, an Air Quality Forecast and Caution has been issued for Boundary, Bonner, Kootenai, Shoshone, and Benewah counties.

Both northern and southern Idaho will be under the influence of two separate upper level low pressure systems today.  The southern system will provide ample opportunity for afternoon thunderstorms across much of the southern airsheds before moving to the northeast this evening.  Surface wind speeds will be between 5-20 mph with gusts up to 35 mph east of Twin Falls to Pocatello.  Surface wind direction will be from the northwest in the Treasure Valley with south-southwest winds across the remainder of southern Idaho this afternoon.  Skies will be mostly cloudy across southern Idaho with partly to mostly cloudy across the Southwest SMA.  Mixing heights will range from 4,000-8,000 feet AGL.  Transport wind speed will be between 5-25 mph and be generally from the south-southwest.  Limited to no smoke impacts are expected across southern Idaho from west to east, respectively.

The northern upper level low pressure system will not generate much in terms of unsettled weather today, instead, bringing increased chance for thunderstorms and precipitation on Tuesday.  This northern system, while not generating much in terms of storms today, will allow for breezy transport and surface winds this afternoon and will continue to support low RH values. Surface wind speeds will range from 5-15 mph and be from the southwest across Boundary County with west-northwest winds across the remainder of northern Idaho.   Mixing heights are expected to from 4,000-6,000 feet AGL over all air sheds with higher values over the Palouse and Camas Prairie. The wind aloft over northern Idaho this afternoon will be from the southwest-west and northwest-west across the Clearwater SMA and will range from 10-20 mph. 

The strongest smoke impacts are occurring across the Idaho Panhandle with light impacts through the Hells Canyon and Clearwater drainages.  This will continue into the afternoon and tomorrow as cloud cover and higher moisture levels associated with the upper level low pressure system persist into Wednesday.  Given the current location of the upper level low, expect impacts from fires burning in central Washington to affect most of the Columbia Plateau and into the Palouse and Clearwater airsheds before turning north tomorrow and impacting the Idaho Panhandle.  Fires along the Idaho/Washington border will continue to affect the northern Panhandle both today and tomorrow from roughly Lake Pend Oreille and north.  By Wednesday, this system may allow for decreased fire behavior and atmospheric scouring of particulates. 

View DEQ near-real time monitoring at:  http://airquality.deq.idaho.gov/

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.  Visit the Idaho Smoke Blog for more information at http://idsmoke.blogspot.com/

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. 

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

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.