The combination of hot temperatures, persistent high atmospheric pressure and very little rainfall this summer has primed vegetation to catch fire and burn hot and fast. Plus, all the rain this winter and spring fed grass growth. So with the sudden stop in rain, there's more grass than usual, which has dried into perfect fire tinder, said Brad Smith, a Texas A&M Forest Service wildland fire analyst.
“By definition, you have to start off with no drought conditions; you can't get the flash drought without having plant growth,” said Texas state climatologist John Nielsen-Gammon.
The drought is an agricultural drought, rather than a hydrological one, because state water levels are relatively normal. It's only the plant life and soil that are extra dry, Smith said.
And these conditions foster destructive crown fires — ones that burn all the way to the tops of brush and timber, according to Smith.
“Fires transition from the surface to the canopies, and when that happens, fires are resistant to control,” he said.
According to the most recent estimates from the Texas Interagency Coordination Center, 121 fires have burned 30,000 acres in Texas, whereas a month ago, 42 fires had burned just 7,500 acres. In May, less than 1% of the state was in drought. Now, in mid-August, roughly 65% of Texas exhibits drought conditions, Smith said.
“And I expect when they publish those (weekly drought monitoring numbers) that will increase,” he said.
Smith is most concerned about what he calls the rolling plains region of Texas: Amarillo to Abilene and Fort Worth. The area's high concentration of juniper trees makes it especially susceptible to fire.
“Fires transition from the surface to the canopies, and when that happens, fires are resistant to control.” — Brad Smith
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“I refer to it as a high-risk fuel type,” he said. “I'm sorry for referring to it as fuel, but that's what burns.”
Texas does have a predictable late-summer fire season, but usually normal to slightly low rainfall keeps the fires in check, and this summer's conditions are definitely out of the ordinary. In fact, it was only a few years ago, in 2015, that Smith first heard the term "flash drought.”
According to Nielsen-Gammon, flash droughts are defined as conditions so dry that they typically occur less than 20% of the time, or once in a decade.
Flash droughts are such a concern during wildfire season because they leave plants with low moisture reserves. In an effort to survive, plants pull moisture out of the soil, desiccating the ground beneath them as well. Under those conditions, instead of burning quickly through the low vegetation and leaving trees relatively unscathed, fires engulf whole trees, rendering them more destructive and hard to control, Smith said.
Last week, he visited the Copper Breaks fire, which has burned 8,000 acres near Copper Breaks State Park, about 80 miles west of Wichita Falls. Flames reached 60 to 80 feet high, scorching through the tops of the juniper trees and leaving little behind, he said.
“I went back to the site the next day, and basically all I could see were skeletons,” he said.
When fires burn that intensely, even aircraft fire crews have a limited effect, Smith said. And the firefighters, many of whom are volunteers, are stretched thin. As tired firefighters struggle to control the fires, there isn't enough time to maintain equipment, and some of it has been damaged as a result, he said.
Although the forest service has called in extra bulldozer and aircraft assistance to help firefighters, a downturn in fire conditions is likely still a ways off. Weather patterns will have to change in ways they typically do between mid-September and October, Smith said.
The flash drought can't end until the high pressure system shifts away from the state, bringing cooler temperatures and drenching rain. Unfortunately, the past week's scattered showers have not been nearly enough, and may have made the situation worse, because they often bring lightning and high gusts of wind to dry or burning areas, Smith said.
And for now, at least, the weather forecast remains steadily scorching: highs of 100 degrees, lows of 80. High temperatures may dip into the 90s near the end of next week, but there are only a few scattered showers likely.
