PHOENIX — As thousands of firefighters used hand tools and hoses to combat the wildfires torching vast stretches of the Southwest, Drew Smith stared into a computer screen at a command center near one of the fiercest blazes and tried to determine which way the flames would veer next.
Some wildfires are mean. Some are wily. Some show exceptional endurance, or fierceness or moxie. The most difficult among them are assigned behavior analysts like Mr. Smith — fire whisperers, as it were — who act as psychologists delving into the blazes’ inner selves.
“This fire is an exceptionally aggressive fire based on how large it has become and how fast it’s growing,” said Mr. Smith, now assigned to the Wallow Fire, which has become the biggest blaze in Arizona history after burning more than 527,000 acres in the eastern part of the state.
Fire behaviorists work alongside meteorologists, given that the weather, especially wind patterns, plays a pivotal role in how a wildfire grows. The topography is also important because fires burn differently depending on whether they are going up a steep slope, across a valley or through a developed area. Then there are what firefighters call the fuels, which are the vegetation and other materials that give fires energy as they move along.
