09/23/2014 Idaho DEQ Smoke Forecast

Updated 1000am MDT Tuesday, September 23, 2014

Valid through Noon MDT Thursday, September 25, 2014

Smoke Outlook

The areas of concern today will be focused on the Clearwater Drainage as well as the Lower Snake River Plain late this afternoon.  The Idaho Panhandle north of I-90 may also see some haze this evening.  It should be noted that widespread haze and light smoke loft is forecast across all of Idaho.  Smoke impacts were relatively local yesterday as all of DEQ’s monitors were in the Good category for the 24hr AQI except for Lewiston, Grangeville, Kendrick, and St. Maries.  The temporary monitor in Riggins was also in the Moderate category while the temporary monitor in Lowell was in the Very Unhealthy category.

A southwest flow sets up over Idaho as an upper level ridge develops over the Great Basin this afternoon.  This will mark the start of a period defined by dry weather and warm temperatures.  This pattern is likely to persist through Thursday morning when a quasi-stationary upper level trough begins to track east across northern Idaho.  This trough will split from the jet stream on Friday, allowing an upper level closed low to settle over California.  Skies are expected to be mostly cloudy in the Southwest and partly to mostly sunny across the rest of Idaho.  Any precipitation will be limited to the McCall area and the Central Idaho Mountains with light rain very early this morning/late last night.  Surface wind speeds are forecast to be between 5-10 mph and 10-15 mph across the Central Idaho Mountains with southeast flow across the Lower Snake and south-southwest winds across southern Idaho while northern Idaho has a slightly more zonal component resulting in a west-southwest surface wind once the inversions lift.  Mixing heights are forecast to be between 3,000-7,500 feet AGL.  Transport wind speed is forecast to be in the range of 10-15 mph.  Transport wind direction is forecast to be south-southwest. 

Smoke impacts today will be focused on late afternoon transport of the King Fire in California into southwest Idaho.  North of I-90 will also experience some smoke and haze all the way north to the border, particularly in the Purcell Trench.  Also likely will be nocturnal drainage of smoke across the lower elevation points in the Clearwater Basin.

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

·         DEQ has installed a monitor in Riggins. http://app.airsis.com/USFS/fleet.aspx

·         DEQ has installed a monitor in Lowell. http://app.airsis.com/USFS/fleet.aspx

o    Riggins monitor is Idaho1001

o    Lowell monitor is Idaho1002

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

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