Wildfire Today

News and opinion about wildland fire

Wildfire Today

Arizona: Fuels and fire behavior advisory

Author BillPosted on Categories UncategorizedTags ,

Posted at the Southwest Coordination Center web site:

Subject: Heavy Fine Fuel Loads Have Created the Potential for More Active Fire Behavior

Discussion: Above-average rains during the summers of 2006 and 2007 have created heavier than normal fine fuel loads in southern Arizona, especially in desert areas infested with Buffelgrass (Pennisetum ciliare).

Many grassland areas in southeastern Arizona (above 3,500’) have had above average precipitation the past two summers, creating a heavy crop of grass. Historically, this situation has been followed by a year with large fires.

In addition, buffelgrass continues to increase in desert areas. Buffelgrass is a noxious, non-native grass that is roughly doubling each year in Pima County. Fuel loads can be 5-20 times greater than annual grasses like red brome. Because it is increasing so rapidly, firefighters may find thick grass in places that traditionally had little. Because the fuel load is so heavy, it can generate fireline intensity and flame length much more extreme than usual for the desert. Strategies and tactics normally used on desert fires may not succeed on buffelgrass fires.

Common denominators of tragedy fires are potentially present in deserts and grasslands: relatively small fires or deceptively quiet areas of large fires; relatively light fuels, such as grass, herbs, and light brush; unexpected shift in wind direction or in wind speed; fire responds to topographic conditions and runs uphill.

Concerns to Firefighters and the Public:

• Flame length in grass can exceed 4 feet at almost any time of year, exceeding capability of hand tools. Flame lengths can exceed 8 feet during fire season, exceeding the capability of light engines.

• Grass fuels can be continuous, creating wide flaming fronts.

• Greater fireline intensity can lead to increased torching of shrubs and increased spot fires.

• Anticipate fire whirls because of a combination of fuel loading, terrain, and unstable atmosphere.

• Heavier fuel load raises moisture of extinction, and active burning may occur throughout the night.

• Normally bare, rocky areas and steep, south-facing slopes may have enough grass to carry a fire.

• Washes and trails that formerly served as fuel breaks may no longer be effective.

• Retardant may be less effective at stopping fires where grass is thick.

• Greater fireline intensity and flame length increase threat to structures, power poles, and other improvements.

• Some Wildland Urban Interface areas are infested with buffelgrass. Increased fire behavior increases risk to structures, improvements, and public safety, and there is potential for more human-caused fires.

• Increased fuel loading increases radiant heat output, therefore increasing the risk of thermal burns.

• The outlook for April-June is for above average temperatures and below average rainfall, exacerbating the problem.

Mitigation Measures:

• Indirect tactics may have to be used more often.

• Maintain situational awareness of fuel conditions and fire behavior.

• Safety zone size may need to be larger than usual for the desert. Safety zones may be harder to find.

• Use of Nomex face shrouds helps protect the face and airways.

Area of Concern: Desert

 

Whole-house fire shelters

Author BillPosted on Categories UncategorizedTags

It’s incredible what you can find on the Internet.

Many of us are familiar with the practice of wrapping a house that will be threatened by a wildland fire with “fire shelter wrap“… similar to the material used in personal fire shelters–as in the picture below, taken on the Big Fish fire in Colorado in 2002. (It worked, by the way.)


But a number of patents have been issued for devices or systems that would wrap an entire house, theoretically in short order, by one-piece units or systems that would deploy the fire resistant material mechanically.

The unit below, patent #5,860,251, issued January 19, 1999, uses inflatable tubes to erect the flexible fabric over an entire structure. Many large fires are wind-driven. I wonder what the effect of a 50 MPH wind would be on the inflatable structure? It would probably end up in the next county.


The system in the photo below, patent #5,829,200, issued November 3, 1998, uses winches, rollers, and pulleys pre-installed on the house to deploy fire resistant material stored on rolls.


I have no idea if these two systems have ever been developed or manufactured, but you have to admit they are, uh, interesting.

New Poll about videos

Author BillPosted on Categories Uncategorized

You may have noticed that we have put a few YouTube videos on the blog. I have an attention span shorter than that of a newt and can’t get into long videos unless they are EXTREMELY interesting. So we try to be very selective and generally choose outstanding, short, videos. And we’ll try to be sure at least 90% of them are about wildland fire….. or SOME kind of fire…. or 50,000 fire-breathing rockets. Having said that, I totally could not resist posting the one about the lighter than air, jellyfish-like, mesmerizing, unmanned aerial vehicle. Did I mention that it is mesmerizing?

But perhaps not everyone likes videos. And some companies or agencies block YouTube on their computer networks.

So we ask you–to find about 4 seconds in your day and let us know what YOU think–by taking the poll on the right.

Insurance company will pay $500,000 for Arizona fire

Author BillPosted on Categories UncategorizedTags

On June 1, 2006 an employee of a fence company started the La Barranca fire by grinding on a metal fence post south of Sedona, Arizona. Six days later the fire was 95% contained after burning 836 acres and 3 houses. At the time, the Coconino National Forest reported that the estimated fire suppression costs were $1.2 million.

The fence company’s insurance company just agreed to pay $500,000 to the US Forest Service to cover a portion of the suppression costs.

HERE is a link to the InciWeb data about the fire.

John Maclean's forward for Stephen Pyne's book

Author BillPosted on Categories UncategorizedTags , ,

John Maclean has written three books about wildland fire: “Fire on the Mountain”, “Fire and Ashes”, and “The Thirtymile Fire”. Recently he wrote a foreword to Stephen J. Pyne’s “Year of the Fires: The Story of the Great Fires of 1910”, first published in 2001, which is being reissued in 2008 by Mountain Press in Missoula.

We have permission from John and Mountain Press to reprint the foreword here. In the excerpt below, John writes about the fires of 1910 and the cabin at Seely Lake, Montana that has been in his family for generations. The entire foreword is worth a read.

“This summer a palpable cloak of heat and expectation hung over the landscape as though the predictable and cherished past had been replaced by an unfamiliar monster. Make no mistake, northwestern Montana is fire country and has been for centuries. The marks of fire, discovered in tree rings when one of the giant larch trees finally thunders to the ground, show that for centuries fire occurred along the shores of Seeley Lake every quarter century or so – until our forebears stopped the cycle in the wake of the Great Fires of 1910, the subject of Stephen Pyne’s Year of the Fires. When I was growing up, the Forest Service, the agency responsible for the federal land around the cabin, did not allow us to cut a tree and even discouraged clearing brush. The offset was the promise that the Forest Service would contain any fire that threatened the area under the full suppression policy that was adopted in response to the 1910 calamity.

That full suppression policy now has been formally abandoned – along with the rule forbidding the cutting of trees around Seeley Lake. In recent years, the Forest Service itself undertook a forest thinning and light burning project in the area. The treated zones provoked complaints in the first year or two because they looked rough, but they have become a glorious sight since then. Densely packed stands of “dog hair” lodgepole pine have been opened up, disclosing centuries-old trees. The big trees, whose growth was stunted in recent decades because they were deprived of moisture and light, now can take their place as giants and future giants. Fuzzy new trees and low brush carpet the forest floor. Wildlife can move freely. Humans can hike or snowmobile through the stands without battling brush. The forest is not fire proof, but a low-intensity fire would likely burn through here without catastrophic damage. Regular clearing by fire is what allowed the giants to grow big in the first place.

During the summer, I mowed down the tall grass near the cabin, felled a couple of dead lodgepole pines, and cleared a year’s accumulation of duff from near the cabin. Then I left the place to its rendezvous with fire – which was not long in coming.”

Maclean’s and Pyne’s books can be found at the International Association of Wildland Fire Books page.