A cool, wet spring is keeping the wildfire hazard to a minimum in many parts of Colorado. But, according to a CU-Boulder wildfire expert, it would only take a few weeks of hot, dry weather to create a potentially dangerous fire season.
"The really critical time period is June," said Tom Veblen, a professor of geography at CU-Boulder who studies the history of wildfires in the West. "It just takes a few weeks of really dry weather, high temperatures and, most importantly, wind."
According to Veblen, Colorado can still get driving, sustained winds in June capable of whipping fire into a raging inferno, a scenario demonstrated horrifically last year by the Hayman fire, the largest wildfire in Colorado's history.
The Hayman fire started last June 8. Fanned by strong winds, it spread quickly, consuming nearly 138,000 acres of drought-ravaged forest and destroying 133 homes before it was extinguished several weeks later.
"All the ingredients were there for a catastrophic fire," explained Veblen. "The fire came during the most severe drought on record for the state as a whole, and the area in which the Hayman fire actually burned was one of the driest areas within the state."
Veblen studies tree rings to understand the relationship between drought and wildfires. The catastrophic fires of last summer are consistent with past droughts, said Veblen.
"Our tree-ring records of fire indicate that we have had other years similar to 2002 in terms of very widespread fire at low elevations," he said. "So the fires of 2002 are not unique in the long-term."
Veblen also points out a wet spring favors the growth of grasses and other vegetation that can contribute to the wildfire danger.
"It's certainly possible that this amount of precipitation will favor the growth of the fine fuels, the grasses," said Veblen. "Then, if that is followed by very dry conditions and very hot conditions, we can get an extreme fire hazard."
According to the National Interagency Fire Center in Boise, Idaho, the fire outlook for Colorado and the Rocky Mountain region this summer will not be as severe as last year, but could be above average due to the persistent drought and below average precipitation in many areas of the Interior West, including southwestern and northwestern Colorado.
Compounding the problem for fire fighters is the increase of drought-stressed and insect-damaged vegetation throughout the West. As damaged vegetation becomes more prevalent, the potential for large, destructive wildfires increases, said Veblen.