SAN FRANCISCO (CBS SF) — The National Weather Service has issued a Flash Flood Warning for Sonoma County until 11 p.m. Tuesday night as heavy rain from the first in a series of storms pounded the Bay Area.

The weather service said the Walbridge portion of the LNU Lightning Complex burn area in North Central Sonoma County had received between 1.5 and 2.5 inches of rain as of 9:40 p.m. and rates could increase.

The excessive rainfall was producing life-threatening flash flooding in mainly rural areas of the North Central county, affecting drainage basins such as Miller Creek and Redwood Log Creek. Residents were urged to move away from recently burned areas as the heavy rains will likely trigger rockslides, mudslides and debris flows in steep terrain, especially in and around these areas.

Earlier Tuesday, authorities in Solano County and Napa County have issued evacuation warnings for portions of the LNU Lightning Complex burn scar because of potential mudslides and flash flooding.

An evacuation warning means there is a potential threat to life and/or property. Those who require additional time to evacuate, and those with pets and/or livestock are encouraged to leave now. Evacuation site(s) will only be set up if the evacuation warning becomes an evacuation order.

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The National Weather Service  has issued a Flash Flood Watch for the LNU Lightning Complex and Glass Fire burn scars from 4 p.m. Tuesday to 4 p.m. Thursday. Heavy rainfall was expected in the area of the Hennessey Fire and residents in the area were urged prepare for potential flooding impacts, such as debris flows, landslides, and flooding. If you feel the need to leave, now is an opportunity to do so safely.

The heaviest rain was expected Tuesday midnight into Wednesday morning. A High Wind Warning was also in effect from midnight to noon on Wednesday. Strong could cause downed trees power lines and possibly impede evacuation routes.

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In Sonoma County, the hills above Santa Rosa are also scarred from the Glass Fire, which began last September near Glass Mountain Road in Deer Park. Today, the Santa Rosa Creek watershed looks more like a moon scape than a forest.

“The National Weather Service says that we will likely get at least an inch of rain an hour,” said Santa Rosa Fire Marshal Paul Lowenthal. “That meets the trigger and thresholds for potential debris flows and mudslides within our burn scars.”

Inside the burn zone Tuesday, a demolition crew was racing against time to stabilize a hillside near homes before the rain began. “Trying to grade this out best we can, get some drainage away from where we’re working and then we’re going to set up waddles around the perimeter,” said Farr Demolition foreman Robert Sexton.

If debris flows do happen, they could sweep through neighborhoods downstream. The Santa Rosa Fire Department went door-to-door on low-lying streets alerting residents to the danger.

All residents in the LNU Lightning Complex burn scar area were urged to have a “go bag” ready.

 

Don Ford contributed to this report.

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