Monday, September 19, 2011
Oregon Governor John Kitzhaber toured the Dollar Lake fire from above Friday afternoon to witness firsthand the difficulties firefighters are facing with the now 4,600-acre fire on the north side of Mount Hood. Despite relatively calm fire behavior over the last few days, additional resources were dispatched to the incident, including National Guard support in the form of Blackhawk and Firehawk helicopters and support crew that arrived Friday.
With Red-Flag fire weather in the forecast and the potential for extreme fire behavior just a slight change in the weather away, management is taking every opportunity it can to get on top of the situation as quickly as possible.
"The fire is in difficult terrain and threatens major power transmission lines and the Bull Run Watershed, which provides water to some 900,000 people in the Portland metro area," noted Kitzhaber's office.
Overlooking the fire's western flank at Cathedral Ridge Thursday afternoon, just a few distant smoke spots were visible. Ironically, crews attempted a burnout operation earlier that morning, but couldn't get it lighted due to high humidity and an inversion layer that has trapped smoke over the fire for several days.
"It's another great day of mild fire weather," Peter Frenzen, USFS information officer, said from the vista. "The fire is being shielded from high winds and unstable atmosphere above by the inversion layer. It makes for pretty calm fire behavior; but the drawback is that it's also making burnout operations very difficult."
Frenzen said crews have secured the east and northeast parameters of the fire, which was an initial primary objective when the fire first made large runs. Winds switched direction last week, however, and pushed the fire on a large run west toward the Lolo Pass area.
Resources will now be focused on the western front of the fire, with crews remaining at important eastern locations like the historic Cloud Cap Inn.
"As soon as the inversion lifts, the fire will be able to reach unstable air and high winds," Frenzen said. "When you combine that with the fuel load and topography of the area, it is a recipe for extreme fire behavior."
"It's an interesting situation," said John Robertson, fire behavior analyst. "Yesterday (Thursday) we had all the ingredients for extreme fire behavior, but local effects prevented that from happening. Over the last four days nightly inversions and topography have been sheltering the fire from upper level winds and an unstable atmosphere. By late afternoon, conditions had improved and burnout operations were completed between Cathedral Ridge and the wilderness boundary."
The western reach of the fire is burning about nine miles east of homes along the Lolo Pass Road and 2-3 miles from the headwaters of the Bull Run watershed.
Watershed representatives noted that the fire is still nearly 20 miles from the Bull Run intake, which is where Portland's water supply is drawn from. They also noted that even if the fire did overtake the intake area, there's no evidence that it would harm water quality.