Updated 1100am MDT Wednesday, August 05, 2015
Valid through: until conditions deteriorate
Air quality is forecast to remain in the Moderate to Good air quality category across the northern Panhandle with short term impacts across the Idaho Panhandle. Impacts are from regional fire burning in primarily in Washington State.
There is an upper level low pressure system located over California that will move to the northeast and into our area today. Ahead of this system, there is strong support for scattered thunderstorms and breezy winds this afternoon across all of southern Idaho. Surface wind speeds will be between 5-15 mph. The surface wind direction will be from the northwest in the Treasure Valley and Magic Valley with west-southwest winds across the remainder of southern Idaho. Winds near thunderstorms will be erratic in direction with gusts up to 50 mph this afternoon. Transport wind speed will be between 10-20 mph and be generally from the west-southwest except across the Treasure Valley where northwest wind directions will occur. There is a Red Flag Warning across all of southern Idaho in effect until this evening.
This will make for an active weather pattern as a cold front passes through northern Idaho. Central Idaho southeast of Grangeville and the northern Panhandle along the Canadian border will be the most favorable spots for thunderstorms and rain today. Surface wind speeds will range from 10-20 mph and be from the west-southwest with northwest winds across the Camas Prairie. The wind aloft over northern Idaho this afternoon will be from the southwest and will range from 15-25 mph except across the Clearwater SMA where winds will be from the west-northwest at 10-20 mph.
The strongest smoke impacts are occurring across the Idaho Panhandle with light impacts through the Hells Canyon and Clearwater drainages. This will continue into the afternoon as cloud cover and higher moisture levels associated with the upper level low pressure system persist into the afternoon. Given the current location of the upper level low, expect impacts from fires burning in central Washington to affect most of the Columbia Plateau with a small chance to impact the Palouse and Clearwater airsheds. Fires along the Idaho/Washington border will continue to affect the northern Panhandle today roughly from I-90 and north. This system may allow for decreased fire behavior and atmospheric scouring of particulates. Light impacts should be expected as far south as the Lower Treasure Valley, including a swath running southwest to northeast through McCall and the Central Idaho Mountains into Salmon. By Thursday, a switch to a zonal flow pattern aloft will limit impacts in southern Idaho will maintain regional transport into northern Idaho from fires in Washington.
DEQ will stop issuing daily smoke forecasts due to reduced wildfire activity and improved air quality throughout the state. Air quality is forecast to remain in the Good air quality category for at least the next couple of days.
To find an air quality forecast for your area, visit the DEQ's Daily Air Quality Reports and Forecasts webpage.
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/
To find information on wildfire activity, visit Inciweb
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.
Unhealthy for Sensitive Groups
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.