A dry, windy spring follows a winter with no rain after two decades of intermittent drought.
That's a prescription for "one of those fire seasons people are going to talk about for a long time," said Don Falk, a fire ecologist who spoke Wednesday at a briefing held by two University of Arizona programs, CLIMAS and UA Science Connections.
It's no coincidence the nation's largest fires are burning this year in a swath that includes southeastern Arizona, New Mexico and Texas. That's the area designated as being in extreme drought this spring, said Mike Crimmins, associate professor in the UA department of soil, water and environmental science.
In addition, said Crimmins, Arizona is being hit by "wind event after wind event after wind event," courtesy of a pressure gradient sitting just to the north that brings storm conditions but no rain.
Fire was the overriding theme of the annual briefing, which usually focuses on the upcoming monsoon.
One scheduled participant, atmospheric scientist Art Douglas, didn't make his planned video appearance because of the Monument Fire burning south of Sierra Vista. Douglas had to vacate his home in Ash Canyon ahead of the flames, Crimmins said.
Falk said northern Mexico is also experiencing its biggest fire season in at least 25 years.
Fire is an inevitable occurrence in forests, he said.
It is "the way ecosystems redistribute excess energy," Falk said.
The severity of fires burning this year is "the legacy of a century of trying to exclude that natural process," said Falk, an associate professor of natural resources at the UA.
The huge fires burning this year won't go out until the rains arrive, he said.
That won't happen soon, said Glen Sampson, meteorologist in charge at the National Weather Service in Tucson.
The current weeklong forecast is for continued hot and dry, and the weather service is giving an "equal chance" for an early or late start to the monsoon, he said.
The average start day for monsoon weather in Tucson is during the first week of July.
Contact reporter Tom Beal at email@example.com or 573-4158.