Bomb cyclone. Rivers of rain. Emergency response officials have been bracing all week for the worst days of the storm — and it finally arrived late Saturday evening. Light scattered showers in Northern California, already burned out by a summer of fire, morphed into an increasingly heavy downpour overnight.
By Sunday morning, the torrential rainfall had shut down at least one critical highway as mud, rocks and unshackled debris flushed down denuded hillsides. Flash flood and excessive rain warnings blared across road signs and phone screens, with some officials declaring that for those in the Dixie fire burn area who had not yet evacuated, it could be too late.
"If you are near a burn scar, it may be too late to evacuate," officials at the National Weather Service in Sacramento said on Twitter, along with a list of safety warnings. "Do not attempt to cross a debris flow. Take shelter in the highest floor of your home."
By 7:30 a.m. Sunday, multiple debris flows had shut down Highway 70 between Jarbo Gap and Greenville, a historic mountainside community in Plumas County that had already lost so much to the Dixie fire. A photo circulating on social media showed a dramatic slide near the community of Tobin, where a huge pile of rock, trees and debris collapsed and inundated both lanes of the highway.
Transportation and highway patrol officers rushed all morning to multiple collisions and reports of fallen trees and overturned vehicles. Numerous roadways are flooded, they noted, including portions of State Route 99. Drivers should avoid areas near creeks and drainages that are particularly prone to flooding during intense rain.
Rain in the Dixie fire region has been pouring at 0.4 to 0.7 inch per hour — a rate that could intensify through Sunday, said Katrina Hand, a weather service meteorologist based in Sacramento.
"We're looking at pretty heavy steady rain through the rest of today into the evening," Hand said Sunday morning. "It will still be raining a decent amount into Monday, but it looks like the heaviest will make its way out by later tonight for that area."
South of the Dixie burn area, along where the Caldor fire scorched the Highway 50 corridor, officials remained on high alert for life-threatening flash floods and debris flows. Heavier precipitation started moving in around mid-morning and is expected to continue its march south. The rain here is expected to pour as much as an inch per hour throughout Sunday and into Monday.
Crews this week have been busy building barriers along rivers and streams, constructing retaining walls and fencing off unstable hillsides that could collapse. Deep-water rescue vehicles have been positioned in high-risk areas, according to the state's Office of Emergency Services, and crews have been deployed to monitor key burn areas.
Flash flood warnings for both the Dixie and Caldor regions are in effect until 3 a.m. Monday. More than a foot of rain could fall in the Sierra Nevada, with up to 3 feet of snow possible at higher elevations through Tuesday, forecasters said.