Idaho has been battling severe wildfires all summer long. Inciweb, the website that tracks fires across the United States, has 23 active fires listed for the state at present. The largest of these fires is the Payette Wilderness fire which is 87,496 acres in size. This active fire site is actually an amalgam of 19 smaller fires (these are not included in the total of 23 wildfires as these are listed under the purview of one fire). The largest of the Payette Wilderness group of fires is the Highline Fire which is 83,630 acres. All of the wildfires in this group are being managed under a natural resource benefit strategy, that is allowing the fire to run its course, with a Point Protection strategy being used as necessary to protect values at risk. The majority of fires in this group were started by lightning strikes.
The smallest fire listed is a 10 acre fire called the Boulder Fire that was reported on September 4, 2017 in the Boise National Forest. This fire was started by a lightning strike.
The overarching problem with wildfires this year has been the weather. Hot, dry conditions descended upon the western states and the weather's grip has not released. Lightning strikes hit dry grasses and undergrowth and wildfires erupt. Without higher relative humidity, and cooler conditions, these fires are able to spread quickly.
The National Weather Service has issued a Red Flag Warning for the northernmost area of Idaho and parts of Montana. According to the NWS: "Breezy westerly winds and low humidity will combine to create Red Flag conditions this afternoon and evening. Winds and humidities will be slow to improve, thus critical fire conditions are expected well into the evening. Winds will be from the west-southwest 15 to 25 mph, gusting to 35 mph mainly for midslopes and ridgetops. Relative humidity will be 10 to 20 percent."
This image was taken by the Suomi NPP satellite's Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on September 11, 2017. The Suomi NPP satellite is a joint mission between NASA and NOAA.
Provided by NASA