Experts weigh impact of wet winter, heat wave on wildfire season
As temperatures soar across the Bay Area, so do growing concerns about fire season, particularly after the region remained relatively unscathed last summer.
Northern California has already experienced its first major wildfire of the season with last weekend's Corral Fire near Tracy, which consumed over 14,000 acres.
"What is the cure time of the grasses, and when will they be susceptible to ignition," said Craig Clements, Director of the Wildfire Interdisciplinary Research Center at San Jose State. "That's something that all agencies, and even the utilities and the research community are all watching right now."
Watching the Bay Area hills turn from a faded green to a light brown, Clements said the past few days have been a reminder that even a good winter has legs when it comes to keeping fire risk down.
"The Coral Fire was a big fire, but it was a grass fire, and grass fires are very common this time of year," Clements said. "They are the first type of fires that we really get."
Grasses are usually cured by early June, so fires are now likely. The next question becomes the larger fuel that is often ignited by a grass fire.
"So these are what we call live fuels, or living plants," Clements explained. "Those living plants have a lot of soil moisture right now because of the wet winter. So they are doing OK in terms of their fuel moisture content. But as we approach fall, those plants become critically dry. And whether it's a wet winter or a dry winter, those plants are still going to respond similarly in the late summer early fall."
The two healthy winters continue to pay dividends. Because of the moisture, the current outlook for large fires is considered below normal this year.
"That could change if we have an extended heat wave, severe heat wave, and that causes further drying, faster drawing of fuels that are generally drying slowly through the summer," Clements said of potential weather variables.
The payoff from the rains is variable, depending on what the fall and summer deliver. The hope is another year of good moisture translates to another year of fewer large fires.
"Hopefully it stays like that," Clements added. "Hopefully we can remain without a lot of big fires."