The Bootleg Fire, the largest among the dozens of wildfires that broke out in the dry tinder landscape of the western United States, has devastated more than 241,000 acres, an area that exceeds the land mass of New York City.
Ironically, the dense smoke engulfing much of the region from the fires may slightly mitigate the effects of another heat wave expected this weekend in the Rocky Mountains, extending to parts of Montana, Idaho, Wyoming, Utah. and Colorado.
The Bootleg Fire has been burning through drought-dried wood and brush in and around the Fremont-Winema National Forest since it erupted on July 6 near Klamath Falls, about 250 miles (400 km) to the south. from Portland. The cause is under investigation.
The flames have destroyed at least 21 houses and 54 other structures, authorities said. On Friday, the Oregon Department of Forestry listed more than 5,000 homes as threatened, about 3,000 more than a day earlier.
That number represents a larger number of communities potentially at risk as the fire spreads, agency spokesman Marcus Kauffman said. Still, fewer homes were in immediate danger, especially along the southern flank of the fire, where crews were most successful.
Consequently, the number of homes under mandatory evacuation roughly halved to just over 200 on Friday, while around 2,700 were placed on hold alerts.
Strike teams have carved containment lines around 7% of the perimeter of the fire. But extreme fire growth fueled by low humidity, dry vegetation and gusty winds forced firefighters to retreat from the fire’s leading edges for a fourth day in a row on Friday, authorities said.
“The perimeter of the pirate fire is more than 200 miles long. It is an enormous amount of line to build and maintain,” Incident Commander Rob Allen said in a statement.
Another heat wave
Allen said hot, dry and windy conditions are expected to work through the weekend, while forecasters forecast the arrival of another major western heat wave, the fourth since early June.
This, which will grill portions of the Northern Rocky Mountains and High Plains through Monday, will emanate from a high-pressure ridge over the southwestern desert, said National Weather Service meteorologist David Lawrence.
That high-pressure dome can help draw much-needed moisture to Arizona, California, Nevada, Utah and southern Idaho, Lawrence said. However, a potential downside is the increased likelihood of dry thunderstorms forming in central and northern California before any rain that may fall there, he added.
More than 1,900 firefighters and a dozen helicopters, as well as tankers and bulldozers were assigned to the smuggling fire, as demand for personnel and equipment throughout the Pacific Northwest depleted available resources.
The Bootleg was ranked by far the largest of the top 70 active wildfires listed Thursday, having burned more than 1 million acres in 12 states, reported the National Interagency Fire Center in Boise, Idaho. It also ranked as the fifth largest recorded in Oregon since 1900, according to state forestry figures.
As of Wednesday, downtown Boise placed its “national wildfire preparedness level” at No. 5, the highest on its five-tier scale, meaning that the majority of America’s firefighting resources are currently deployed somewhere in the country.
The situation represented an unusually busy start to the annual fire season, amid extremely dry conditions and record heat that have burned through much of the West in recent weeks.
Scientists have said that the increasing frequency and intensity of wildfires can be largely attributed to prolonged drought and increasing episodes of excessive heat that are symptomatic of climate change.
Nearly 70 National Weather Service stations across the West have recorded record highs this summer, and several hundred record highs have also been set for specific dates, Lawrence said.
The Bootleg fire is so big it generates its own weather. Towering pyrocumulus clouds are formed from condensed moisture that is sucked through the fire smoke plume from burned vegetation and the surrounding atmosphere, and can generate lightning and strong winds.
The sudden “collapse” of one of those clouds on Friday spread the embers east of the main area of the fire, prompting additional evacuation notices for two communities, Allen said.