Flash flood watch for possible debris flow in Northern California wildfire burn scars
The National Weather Service issued a flash flood watch alert, warning residents of possible debris flows in the burn scars of five Northern California wildfires as more heavy rain is expected Wednesday.
The alert was issued from 4 p.m. Wednesday through 7 a.m. Thursday for the burn scars of the Mosquito Fire, western side of the Caldor Fire, the River Fire, the August Complex Fire and the western side of the Dixie Fire. People near a burn scar should be prepared to evacuate if told to by local officials.
Weather service forecasters warned that heavy rainfall rates can lead to flooding and debris flows over recent wildfire burn areas. They urged residents to get out of debris flow danger areas before Wednesday’s storm arrives and move to higher ground away from rivers and streams.
About 1.5 to 3 inches of rainfall was expected in the Sacramento area from Wednesday evening through Thursday morning. Residents should expect areas of urban flooding with renewed rising water levels in streams and creeks, along with rising river levels.
The weather service cautioned residents to stay alert if living near streams and creeks, follow evacuation orders and be especially cautious when driving at night.
Corey Mueller, a meterologist with the weather service, said residents in the foothills should expect to see “a strong winter storm” to arrive on Wednesday. He said the snow elevation levels, starting around 4000 feet Wednesday, should be lower Wednesday than what occurred over the New Year’s weekend, which should prevent some runoff.
But Mueller said runoff is expected with long periods of heavy and moderate rain throughout the region. The weather service expects rainfall rates approaching one-hour thresholds in the wildfire burn scar areas under alert Wednesday evening in the Sierra Nevada foothills, southern Cascades and Coastal Range.
The Mosquito Fire burned dozens of homes in the foothills east of Sacramento and 76,788 acres (120 square miles) in Placer and El Dorado counties before it was fully contained in late October.
The Caldor Fire destroyed hundreds of homes in rural El Dorado County, burned 221,835 acres (347 square miles) and forced the evacuation of tens of thousands of residents in and near South Lake Tahoe before firefighters fully contained the blaze in October 2021.
Firefighters battled for nine days in August 2021 before they contained the River Fire, which destroyed nearly 150 buildings in Placer and Nevada counties and burned 2,619 acres.
The August Complex Fire is the largest wildfire in California’s history with 1,032,000 acres burned in 2020 in the Mendocino National Forest. The Dixie Fire in 2021 became the state’s second-largest wildfire in 2021, when it burned 963,000 in rural Plumas County.
This story was originally published January 3, 2023 at 5:20 PM.
