Fire behavior expert talks tactics
If weather conditions continue to cooperate with fire crews, tactics such as back burns can continue to be used with success.
But it only takes a shift in the wind to undo containment lines, said a fire behavior analyst at the Yuba River Complex incident command center at the fairgrounds Tuesday.
Drew Smith discussed various scenarios after flying above the fires burning near the town of Washington and west of Bowman Lake Road.
“We can’t get a control line around the entire fire because of the topography,” Smith said.
Igniting a back fire with hand torches and from the air has been used on some portions of the fires within the complex. That strategy is being considered to control the fire advancing along the western and northeastern flanks of the Fall Fire.
Firefighters typically light back fires after 4 p.m., after the hottest time of the day has passed, allowing the fire to spread at a slower rate and lower intensity.
“If we let the fire do it on its own, it may do so at the least of our advantage,” Smith said.
So far, the firefighting tactic has been used along the Clear Creek drainage and road systems along Bowman Lake Road, where the Fall Fire has burned 1,854 acres and is 67-percent contained.
Fire moves when humidity drops into the teens, outside temperatures rise above 80 degrees and wind speeds rush beyond 25 miles per hour, Smith said.
“One thing in our favor is there is no forecast of northerly winds,” Smith said.
But the outlook could change quickly if violent winds blow through the South Yuba River canyon. It’s not uncommon for flaming twigs and vegetation to blow one-quarter to one-half mile beyond the fire front, jumping manmade fire breaks such as roads or natural ones like rivers, Smith said.
“That’s one of our biggest concerns – spotting,” Smith said.
In areas where fires have already swept through and burned low growing surface vegetation, the potential for a “reburn” lurks, because the fires’ heat have made low-lying branches tinder-dry, Smith said.
So far, the Fall Fire has moved slowly, averaging about 200 acres per day. But fighting the fire is a complex task with the area’s steep terrain, the forest’s dry and dead fuels, and the competition for air resources to fight the fire. Those factors have contributed to slow containment, Smith said.
“If we were the only show in town, we would have been done a long time ago,” Smith said.
To contact Staff Writer Laura Brown, e-mail firstname.lastname@example.org or call 477-4231.
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