Friday, June 18, 2010

Horseshoe Fire: Strategies

At last night's community meeting in Portal regarding the Horseshoe Fire, the fire team gave us a glimpse into how their strategies are built. Sam Amato (an analyst of long-term fire behavior) has modeled the fire, using local topography, weather patterns, and knowledge of fire behavior, to map the Horseshoe's predicted behavior over the next 7 and 14 days.

Probability of fire spread in 7 days, given no suppression

Operations Chief George Johnson noted that "all models are wrong––some are useful." And indeed the usefulness of these two models is obvious. By looking at the most likely flow of fire through the landscape, the fire planners can see the most important points to choke off the fire to prevent its spread into sensitive areas. Sometimes those points can be worked on the ground, but in terrain this rugged, aerial attack is usually more practical and much safer for the firefighters. Even when a fire can only be dampened or delayed at those check points, it helps, buying us more time for the rains to arrive.

I also found some comfort in looking at the worst case scenario presented by the 14-day model, and noting just how extremely low the chances are that that worst case would happen: it's less than 0.2%! The worst case scenario also isn't as bad as imagination would make it. None of the fire officials last night were willing to say positively that the fire won't reach Portal, but they all believed that the likelihood is extremely low.

Rains are falling now in Mexico, and the meteorologist said this morning that with luck they could reach the Chiricahuas sometime next week.

The type of fire team now working on the Horseshoe Fire specializes in long-term strategy. The initial Type 1 team had a different mission, that of overwhelming the incident.

At this morning's briefing to the fire crews, the day's plan was laid out and an updated fire map posted.

Fire map at June 18 briefing
Left blue box: South Fork picnic area. Right blue box: Portal Peak

Today's planned operations include continuing to brush and chip along Forest Road 42, beginning to brush the South Fork Road, checking yet again for any smoke or hotspots in the South Fork bottom, and sending a team to the fire line at "B" and "A" along the perimeter (see blue lines on map). Along "B" and "A" the team will be putting in water bars to reduce erosion in the fire perimeter, once the rains arrive. They were cautioned to watch for illegal immigrants and smugglers, because the new fire line provides a much easier trail for illegal border-crossers to use.

Along the fire margins, crews have been "cold-trailing," testing by hand to see whether the soil is cold, or retains heat. A few smokes have broken out within the main burn, as remaining fuel continues to dry out and begins to smolder.

Tomorrow's census of Elegant Trogons will be held, although only people trained to work with wildfires will be allowed into South Fork. At least three such folks are also birders and are familiar with trogons. We'll meet this evening at 6 PM at the Visitor Center in Cave Creek Canyon to organize the effort.

Incident Commander Brad McBratney spoke to our attitude as a community toward this crisis. Being in crisis mode for a long period is a strain. It will help if we recognize that we have time here, nothing is imminent, and "it's a marathon, not a sprint." We need to pace ourselves, to draw on our stamina, and to release that stress as much as possible.

So, a question for Hizzonner the Mayor: shall we have a community gathering to hear your latest joke collection, or compilation of urban legends?

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