09/01/2015 Idaho DEQ Smoke Forecast

Updated 1:00pm MDT Tuesday, September 1, 2015

Valid through: Noon MDT Friday, September 4, 2015

Smoke Outlook

Air quality is currently ranging from Good to Moderate in all of Idaho with higher hourly impacts across the Clearwater Basin Drainage and the Salmon-Challis area.  Air quality is forecast to remain in Moderate to Unhealthy category for the 24hr standard across central Idaho today while northern Idaho has seen some improvement and is forecast to be in the Good to Moderate category. Southern Idaho remains in the Good category.  Impacts are from regional fires burning in Washington State, California, Oregon, and a multitude of local fires in the Clearwater drainage, the northern Panhandle, and Central Idaho Mountains.

Nez Perce Reservation:  24-hour monitor readings range from Good to Moderate.  Hourly readings are fluctuating from Moderate to Unhealthy, depending on location and wind direction.  The Nez Perce Tribe has lifted their Air Quality Advisory.  Please contact the Nez Perce Tribe for more information: airquality@nezperce.org.

Generally speaking, the winds at the surface will be from the southwest-west with regions of northwest within the Treasure Valley and over the Clearwater drainages at 5-10 mph with winds from 8-12 mph across the Rathdrum Prairie and Purcell Trench.  It should be a dry day with partly cloudy skies in the northern Panhandle and mostly sunny skies elsewhere.  On Wednesday, a cold front will move in affecting northern Idaho first before entering southwest Idaho tomorrow evening.  This will bring cooler, stormier weather for the remainder of the week.  Several small disturbances will pass through as the weekend approaches.  These events will serve to bring precipitation and higher, sometimes gusty, winds by Friday.

 

The strongest smoke impacts are occurring across the Clearwater drainages with lighter impacts in the McCall region.  Expect to experience impacts from the Canada border south to the Salmon River corridor with some drainage impacts into the McCall and Salmon area.  The highest impacts are expected to be within the drainages of the Clearwater and Salmon down into the Lewiston-Clarkston Valley due to the proximity of large fires currently burning.  The Purcell Trench may also see some impacts in the northern tier within Boundary County.  In southern Idaho, impacts will be greatest within the drainages around McCall and the Lower Treasure Valley and generally north (and including) of a line running from Weiser to Salmon.  By Wednesday, there may be regional smoke transport from California over southern Idaho.  This is not expected to impact at the surface.  

Conditions have generally improved across all of Idaho with values in the Good and Moderate range.  Nighttime drainage smoke will continue to provide impacts in regions near and downwind of the fires.  Impacts in the central Idaho region will continue to be the greatest.  Fires burning in northeast Oregon and southeast Washington will continue to add smoke into the Palouse region.  Clearing should be expected over the open expanses with greater improvement expected from Wednesday on through the weekend.

DEQ Air Quality Advisories:

Idaho DEQ has issued an Air Quality Advisory:

·         Lewiston Regional Office for  Clearwater and Idaho Counties, (off the Nez Perce Reservation) through September 2^nd at 10:00am when it will be extended or lifted.

View real time smoke monitoring at:  http://www.airnow.gov/index.cfm?action=topics.smoke_wildfires

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

 The USFS installed monitors in Riggins, ID, Halfway, OR, and Newport, WA.  The information can be found at http://www.wrcc.dri.edu/cgi-bin/smoke.pl

·         Riggins, ID monitor is Smoke USFS R1-306

·         Halfway, OR monitor is Smoke #68

·         Users should be aware that the Forest Service site reports the data in Coordinated Universal Time (UTC).  To convert from UTC to Mountain Daylight Time, subtract 6 hours.

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.