08/19/14 Idaho DEQ Smoke Forecast

Updated 1000am MDT Tuesday, August 19, 2014

Valid through Noon MDT Friday, August 22, 2014

Smoke Outlook

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

• Idaho County (Off the Nez Perce Reservation)-effective  through 10:00am PDT August 19, 2014, at which time is will be re-evaluated and either extended or lifted.

The areas of concern continue to be in the Clearwater Basin due to the proximity of local fires, there is some transport of smoke from fires burning in California, Oregon, and Washington.  Smoke impacts were limited to regions close to fires as DEQ’s monitors were slightly elevated and in the Good and Moderate categories yesterday.  The emergency monitor at the Fenn Ranger Station was also in the Moderate yesterday.  The Idaho Panhandle saw slightly elevated values in some spots due to fires burning in Washington state.

The shortwave trough currently located over Canada will sag and bring a cold front over Idaho this evening.  Leading up to this passage, we will experience a more active weather day with respect to winds, thunderstorms and showers.  The closed low over California will continue to funnel monsoon moisture into southern Idaho before shearing to the east.  The cold front is forecast to pass through Idaho beginning late this morning in the north while not passing through southern Idaho until late afternoon and into early Wednesday morning.  As this front approaches, there is an increased chance for showers along the Southern Highlands and Central Idaho Mountains.  Generally, the surface winds will be from the southwest and will be moderate in speed due to the surface pressure gradient tightening in response to the approaching front.  Skies are expected to be mostly sunny all day.  Transport wind direction is forecast to be from the south-southwest over southern Idaho at 5-20 mph with faster speeds over the southeastern part of the state.  Temperatures are forecast to be slightly cooler through the week with increasing chance for showers and higher relative humidity levels.  The low over Canada will be relatively stationary, keeping much of Idaho in the nadir of a shortwave trough for much of the week.

Smoke impacts today will continue to be strongest across the Clearwater with locally heavy impacts near fires with some light transport into central and north Idaho.  Smoke will settle into the drainages again this evening.  This weekend will bring light smoke through the Snake River Plain.  Higher values should be expected in the morning before the inversion breaks.  Smoke from fires burning in Washington will be transported into the Panhandle region once more this afternoon.

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

·         Fenn monitor is Smoke#25

·         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