08/02/2016 Idaho DEQ Smoke Forecast

Updated 10am MDT Tuesday, August 2, 2016 

Valid through Noon MDT Wednesday, August 3, 2016 

Smoke Outlook

Air quality is forecast to remain in the Good to Moderate air quality category across the state today.  Fire activity has increased around the Pacific Northwest with large fires burning in Idaho, Washington, and Oregon.  Impacts are occurring outside Idaho City where current monitor readings are elevated into the Unhealthy category.  Additional impacts are being recorded east in the Ketchum area which is currently reading in the Moderate category.  Much of south Idaho is currently reading into the Moderate Category, including the Nampa/Meridian area, Twin Falls, Burley, Franklin, and Idaho Falls.  Salmon is currently in the Unhealthy for Sensitive Groups Category.  In north Idaho, monitor readings are currently in the Moderate category across the Camas Prairie, down into the Lewiston-Clarkston Valley and north into the Silver Valley and on the Coeur d’Alene Reservation.  This is likely due to the fires currently burning in eastern Washington and Oregon.  Expect higher readings in the evening and early morning before improving during the day.

An upper level low pressure system is currently over northern Washington.  This system is generating a tight surface gradient which will provide strong winds today across much of Idaho.  Expect surface winds from 10-20 mph across the state with gusts from 25-35 mph.  Wind direction will be from the west-southwest with locally northwest winds over the Treasure Valley, west Magic Valley, and Camas Prairie.  Mixing heights will range from 4,000-11,000 feet AGL this afternoon and transport winds will be from the southwest-west again with locally northwest winds over the Treasure Valley, west Magic Valley, and Camas Prairie at 15-30 mph.  This system will bring a cold front through southern Idaho this afternoon.  Monsoon moisture through the eastern Great Basin will offer isolated thunderstorms over the Southern and Southeast Highlands today.

Tomorrow, the upper level low pressure system will track east into Montana, but will still provide for a chance of showers across the extreme northern Panhandle.  Elsewhere, strong, gusty winds will continue.  Expect winds from the west-northwest with southwest winds within the Purcell trench and the Upper Snake River Plain.  Surface wind speeds will range from 5-10 mph across north Idaho and 10-20 mph across south Idaho.  Mixing heights will range from 2,000-6,000 feet AGL in the afternoon with transport winds from the northwest-west at 10-15 mph.  Again, the Purcell Trench and Upper Snake River Plain will see southwest transport winds at 5-10 mph and 10-20 mph, respectively.

Smoke impacts today are likely to occur downwind of the Pioneer fire.  This includes Idaho City, Ketchum, and the Middle Snake River Plain from Mountain Home to Pocatello.  Transport into Salmon is again likely during the day today.  Transport from fires in eastern Oregon and Washington are expected to affect the Palouse, Weippe, and Camas Prairies in central Idaho this morning and early afternoon and should lift this afternoon before settling in valleys tonight.  Smoke is also expected to enter the Lower Treasure Valley today from fires in eastern Oregon.  Tonight, surface level smoke will drain down into the Snake River Plain in and around the Arco Desert region east to Salmon before dispersing to the northeast via the Upper Snake tomorrow.  The regions that may see smoke this evening will extend through the Snake River Plain into the Island Park area.  Impacts are expected to be highly localized, once the inversion lifts tomorrow morning, again most likely affecting Ketchum and Salmon while a shift to northwest winds may allow increased clearing across the Clearwater, depending on fire activity.

 DEQ Air Quality Advisories:

·         The Twin Falls Regional Office has issued a Stage 1 Forecast and Caution for Blaine County.  Valid through 1pm August 3^rd.

·         The Lewiston Regional Office has issued a Stage 1 Forecast and Caution for Clearwater, Idaho, Latah, Lewis, and Nez Perce Counties (off the Nez Perce Reservation).  Valid through 10 am August 2^nd.

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/

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.