Southern California is fighting a trio of aggressive wildfires as a heat wave induced record-breaking temperatures and drier conditions. The Line Fire in San Bernardino, the largest of the three, has scorched more than 26,000 acres. Orange County’s Airport Fire and Angeles National Forest’s Bridge Fire are both growing. Tens of thousands of structures are at risk, and thousands of people have evacuated. Governor Gavin Newsom has declared a state of emergency and called the National Guard for assistance.
Fire crews right now are facing a dangerous combination of dry air, blistering temperatures, and winds that can send the blazes in any direction without warning.
Intense fires can create their own weather systems, which can exacerbate conditions on the ground.
“Heat itself rises and causes these plumes of smoke,” explains David Shew, Napa County’s fire administrator and former CAL FIRE staff chief. “And they can cause enough currents of wind. … When you get enough heat — fires live with oxygen — and so it can draw a lot of oxygen into it, which then causes those wind currents to become even stronger.”
He continues, “Based on high and low-pressure systems, these fires can collapse and cause a vast wind force at the ground level which is very, very dangerous to not only firefighters but the public in general, and can spread those fires much, much faster.”
How optimistic is Shew about getting the current blazes under control? It mainly depends on the weather, he says.
“The fuels, the vegetation, everything that is being exposed to those high temperatures and low humidities means that they are extremely dry and very receptive to ignition. So that is helping to … cause the fire to grow with faster speed and intensity than you would if it were cooler and moister.”
He says California is well equipped to handle multiple fires at once because crews and resources from different regions can be moved to where they’re needed.
“Cities, and counties, and the state itself, and federal partners, and our native partners, and things like that can all join the mutual aid system, and then agree to be called out at a moment's notice to go help their neighbors when an emergency becomes too big for a local jurisdiction to handle on their own. And they can reach out and ask for help when needed. … It's a very well-established system.”
In especially dire circumstances, fire sieges are formed, and can consist of crews from other states and countries.
Meanwhile, many insurance companies are no longer willing to cover homes in fire-prone areas. Shew, who has consulted with the industry, says insurers are reexamining what they can offer and what steps homeowners are taking to protect their properties.
“Those actions that people either take or don't take at an individual property level and at a neighborhood and community-wide level are going to have a great deal of influence in the near future, within the next several years, of insurance companies deciding whether the risk is worth writing policies or not.”
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