The heavily forested Northern Sierra and Southern Cascades have been largely spared the devastating wildfires expected in this epic summer of drought. Not so for the coastal ranges from Napa County to the Oregon line. The reason? A mix of weather patterns, topography and simple bad luck.
Brenda Belongie, a meteorologist with the U.S. Forest Service, said one of the defining events of the fire season involves the remnants of hurricane Dolores in late July.
“It dropped a lot of precipitation over the eastern portion of Northern California, in other words over the Cascades and the Sierra, but not so much on the western side, in the Mendocino County Coastal Range and further north across the Trinity Alps and Salmon Mountains,” she said.
While the heavier cloudbursts were mainly limited to the Sierra crest, high-altitude lightning strikes were widespread. Aided by higher humidity and rain, attack crews made short work of numerous Sierra and Cascade blazes.
In the Coast Range, where vegetation had spent months curing under a scorching sun, the fires quickly grew out of control.
Belongie said the steeper and rougher topography of the Coast Range bring added challenges to firefighting. She said many areas are simply too steep for crews to work safely.
There’s little to suggest that fire risk in the Sierra and Cascades have diminished. Small blips in the weather, like the path of remnants of Hurricane Linda, expected to drift by this weekend, can change everything quickly.
“We’ve basically been in a dry kiln all week with very warm weather and very dry conditions,” Belongie said. That, she said has left the entire region vulnerable to fast growing fires.