Wildfires - August 2007
Fire activity was focused across the Pacific Northwest and Northern Rockies this past month. At the end of August, wildfires were burning primarily across central Idaho and western Montana, and by early September activity had spread southwestward across parts of California.
As of August 31st, 40 large fires were actively burning, with fire activity and poor air quality conditions persisting across central Idaho and northwest Montana. Wildfires also continued to affect parts of the Yukon, Northwest Territories, and north–central Canada this past month.
According to estimates from the National Interagency Fire center (NIFC), as of September 10th almost 70,000 wildland fires had been reported across the U.S. so far in 2007, with approximately 7.37 million acres burned.
Unusually dry conditions and severe–to–extreme drought across most of the West have resulted in a large region of extreme fire potential according to the U.S. Forest Service (USFS) experimental fire potential index. At the end of August, the highest fire danger remained across parts of California, the Northern Rockies, and the northern High Plains.
The numerous active fires generated vast smoke palls and poor air quality across northern portions of the Great Plains. By mid–August, the smoke pall generated by wildfires in Idaho and Montana had spread eastward into the Tennessee Valley and the Southeast.
Dead fuel moisture levels have remained extremely dry across the western U.S. during August. The 10–hour fuel moisture levels on September 3rd were exceptionally dry throughout most of the western U.S.
|Totals as of August 31st||Nationwide Number of Fires||Nationwide Number of Acres Burned|
Medium to larger fuels (i.e., the August 31st 100–hr and August 31st 1000–hr fuel moistures) were also very dry, with exceptionally dry fuel conditions across an area that encompassed northern Nevada and southern Idaho.
The Keetch–Byram Drought Index (KBDI), a widely used drought index for fire risk, had the largest potential for wildland fire activity in the contiguous U.S. across a large portion of California, as well as over most of the Lower Mississippi Valley, the Tennessee Valley, and the Southeast.