08/11/14 Idaho DEQ Smoke Forecast

Updated Noon MDT Monday, August 11, 2014

Valid through Noon MDT Tuesday, August 12, 2014

Smoke Outlook

Idaho DEQ has issued a Stage 1 Forecast and Caution for the following areas:

• Latah, Nez Perce, Idaho, Lewis, and Clearwater Counties (Off the Nez Perce Reservation)-effective  through 10:00am PDT August 12, 2014, at which time it will be re-evaluated and either extended or lifted.

Idaho DEQ monitors are currently populating data and nearly all are reporting after a data communication interruption.   The areas of concern continue to be in the Clearwater Basin due to the proximity of local fires, and to a lesser extent, the Panhandle due to transport from fires burning in British Columbia, Washington, Oregon, and California.  Hourly values in the Unhealthy for Sensitive Groups and Unhealthy are currently being observed from McCall north to the Grangeville area.

The upper level ridge pattern currently running northwest to southeast over the Continental divide will push to the east as a low pressure system currently off the San Francisco Coast will progress northeastward this afternoon.  This will provide south-southwest transport winds and introduce monsoon moisture into the southern parts of Idaho.  The ridge axis is providing light surface winds across northern Idaho today and high temperatures in the mid-90’s with spots approaching 100 in the low elevations in and around the L-C Valley.  With such high surface temperatures, mixing heights are forecast to be quite high today, from 6,000-10,000ft AGL across the state; however with the location of the upper level ridge, air movement will be stagnant in the horizontal directions.  Conditions remain favorable this afternoon for lightning over the mountains.  Wind speeds at the surface will range from 5-15 mph across the state with light wind speeds north of the Salmon River.  Generally, the surface wind direction will be from the south-southeast in the south with northwest to northeast flow north of the Salmon River.

Smoke impacts today will continue to be strongest across the Clearwater with locally heavy impacts in and around the Grangeville area due to the proximity of the Big Cougar, High Range, and Johnson Bar fires.  Model forecasts indicate little horizontal movement over the next day and half with weather conditions becoming favorable for increased fire activity.

The USFS has installed a monitor at the Fenn Ranger Station.  The information can be found at  http://www.wrcc.dri.edu/cgi-bin/smoke.pl

o    Fenn monitor is Smoke#25

o    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

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. 

 Refer to the Smoke and Health Tab on the Idaho Smoke Information Blog for additional health information. 

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