The Rocky fire has become the blaze of perplexing whims, baffling fire officials with a mercurial nature that computer models and simulations could not predict. Sweeping across three counties in Northern California, the fire has plowed through containment lines, hurdled over a highway — even managed to create its own weather system.
“This fire wants to do whatever it wants,” Cal Fire spokesman Jason Shanley said. “It’s defying all odds. Thirty-year, 40-year veterans have never seen this before.”
Perhaps the most frustrating trait of the massive blaze — 67,000 acres, about the size of Sacramento — has been its ability to suck up heat, energy and moisture, then shoot those elements into the air to form a mushroom top of smoke and ash. Every so often, that plume crashes to the ground, either because of its own weight or because of a temperature drop, which sends flames and wind rushing around it in all directions.
One fire behavior expert likened the effect to a child stomping into a puddle — except that instead of water splashing everywhere, it’s fire, heat and ash, along with winds that move up to 50 miles per hour.
“That’s the killer,” said Bill Patzert, a climatologist with the Jet Propulsion Laboratory. “In some cases, you can’t outrun it. It’s like an explosion.”
Patzert pointed out that high-pressure systems carrying hot, muggy weather and pushing winds north along the coast are colliding with a low-pressure system, resulting in higher winds. He also said that while the drought-parched region isn’t likely to have an effect on the amount of fires, dry conditions will add to their intensity.
“Once they start up, they burn hotter. They’re less controllable,” he said.
Breaking out Wednesday near Clear Lake in a rugged region north of Napa, the Rocky fire scorched 8,000 acres by the following afternoon. Computer models estimated it would take seven days for it to double in size. But on Saturday it exploded across 20,000 acres in just five hours. Fire retardant, break lines and backfires could not contain its flames.