Despite heavy rains, Bay Area plants already losing moisture ahead of fire season
SANTA CRUZ MOUNTAINS -- The powerful atmospheric rivers slamming the Bay Area have dumped a tremendous amount of water to the region, causing our rivers and reservoirs to rise and our hills to turn vibrant green.
Students with San Jose State University's Wildfire Interdisciplinary Research Center are calculating the moisture content in the Santa Cruz mountain plants. They're looking at how this winter's rain could impact the upcoming wildfire season.
Grad students Maritza Arreola and Marc Buchs loaded up their fire weather lab truck to get ready for their field research.
"We are going up to our fuel sampling site which is in the Santa Cruz mountains," said San Jose State University graduate research assistant Arreola.
Every two weeks, you can find Arreola and Buchs driving up winding, bumpy roads to the top of Mt. Umunhum.
"I have been doing this for quite a long time since 2016 when I was an undergrad in university, and I'm a graduate student now," said Arreola. "So yeah, I took a little break. But I still have done this for like, a lot of years."
Arreola and Buchs are measuring the moisture content in these plants. The more moisture, the harder it will be for them to catch fire.
"So right now, we're going on our way to the site, the Umunhum site, where we fuel sample," said Arreola. "It's a lot more green. There are a lot more plants around.
They're surprised they're not seeing any new vegetation since they were last here two weeks ago. But they expect new growth soon with more sunshine.
They're especially interested in chemise and manzanita plants which grow abundantly in the Santa Cruz mountains. They take samples of the plants, enough to fill three cans of chemise and one can of manzanita.
Back at San Jose State University, they weigh the plants. Then they put them in the lab oven for 24 hours to dry them out, calculating the difference to get the moisture content.
"The average fuel moisture content is way higher in comparison to the last three years when we were looking at the grass," said Buchs. "Hopefully, it stays that way. But that has yet to be determined."
Last month, the moisture content in these Santa Cruz mountain plants were more than 90% to over 100%. But Arreola warns it doesn't take long for these plants to dry out quickly.
"If we didn't get rain for a lot of days, like if it was really hot, like a heat wave, I would say maybe a week it could get to dangerous levels. Because it would be just like an oven kinda just baking out in the sun," said Arreola.
That's why Arreola said even though the moisture content is good now, it doesn't necessarily mean we're safe this wildfire season.
"I think it could still be pretty bad even if we're not in a drought," said Arreola. "If a lot of new growth starts in April or May, then it could all just dry out in the coming months, and that'll be a lot of risk for wildfires and stuff. So the coming wildfire season may be as bad as others. Maybe even worse because of the new vegetation that's been growing."
While our Bay Area hills look lush and green with so much vegetation now, they likely won't stay this way, drying out in the heat this Summer, quickly turning into highly flammable fuels, which could mean an extreme wildfire season to come.
The results of the latest fuel moisture samples in the Santa Cruz mountains showed plants are already starting to lose their moisture, dropping 10% to 26% from two weeks ago. Their moisture content of chemise and manzanita plants is now just over 80% to 90%.
