Evening storm update: Rainy conditions continue as a second cyclone arrives in Mendocino County

MENDOCINO CO., 11/21/24 – Mother Nature continues to batter Mendocino County and our NorCal neighbors with copious amounts of rain.  

According to the National Weather Service, an atmospheric river is sitting on top of the region, spewing out rain averaging half an inch an hour.  

The atmospheric river is the result of a bomb cyclone, when a cyclone rapidly intensifies over a 24-hour period, according to the National Oceanic and Atmospheric Administration. 

And this is a “buy one bomb cyclone, get one free”: a second one is on the way, expected to arrive off the Mendocino Coast on Friday.  This second storm will bring another four to six inches of rain, high winds and what the weather service calls “life-threatening flooding” to the region tonight and Friday.  

Some areas of the county have seen over 19 inches of rain so far 

Since Tuesday, the highest elevation of Mountain View Road east of Manchester has reported 19.2 inches of rain. You read that right. 19.2 inches of rain.  

Second in the highest rain category is Black Mountain, reporting 12.4 inches.  

Other rainfall amounts recorded in the past 48 hours include 11.2 inches in downtown Laytonville, 9.8 inches along state Highway 20 between Fort Bragg and Willits, 9.12 inches in Philo, 8.4 inches in Boonville, 7.6 in Hopland, 6.1 inches at the Ukiah Municipal Airport, 5.9 inches in Redwood Valley, 4.2 inches in Covelo and 3.4 inches in downtown Mendocino.  

More rain expected Friday, here’s what to expect

The second cyclone will bring more rain on Friday. Thunderstorms may be possible in some areas late Friday night. Temperatures will also be chillier in the evening. Here’s the forecast:  

• Boonville: 1 to 1.5 inches of rain, high of 62 degrees, low of 41 degrees 

• Covelo: Half to 1 inch of rain, high of 57 degrees, low of 34 degrees 

• Fort Bragg: Half to 1 inch of rain, high of 59 degrees, low of 46 degrees 

• Gualala: 1 to 1.5 inches of rain, high of 56 degrees, low of 47 degrees 

• Hopland: 1 to 1.5 inches of rain, high of 59 degrees, low of 40 degrees 

• Laytonville: Three quarters to 1 inch of rain, high of 55 degrees, low of 40 degrees 

• Leggett: 1 to 1.5 inches of rain, high of 58 degrees, low of 41 degrees 

• Mendocino: Half to 1 inch of rain, high of 59 degrees, low of 46 degrees 

• Piercy: 1 to 1.5 inches of rain, high of 58 degrees, low of 40 degrees 

• Point Arena: 1 to 1.25 inches of rain, high of 59 degrees, low of 48 degrees 

• Potter Valley: 1 to 1.50 inches of rain, high of 59 degrees, low of 36 degrees 

• Redwood Valley: Three quarters to 1.5 inches, high of 59 degrees, low of 43 degrees 

• Ukiah: Half to 1 inch of rain, high of 61 degrees, low of 45 degrees 

• Willits: Three quarters to 1.25 inches, high of 55 degrees, low of 39 degrees 

Rain is expected to continue throughout the weekend with fewer impacts expected than what we’ve seen this week so far. You can find your microclimate forecast at weather.gov. 

“Life-threatening” flooding is of concern going into Friday 

According to the weather service, soil across the region is heavily saturated due to the large amount of rain the county’s received. As a result, the ground can’t hold any more water, so it runs off into streams, creeks and rivers, which in turn flood.  

Friday is when a second round of heavy rains will occur. “The concern for major life-threatening flooding will increase during this time frame,” said the weather service.  

A mix of flood watches, warnings and advisories cover the county. One thing is true no matter where you live: flooding is possible, and the threat should be taken seriously.  

The weather service has categorized Mendocino County into two flood threat risk zones: high risk meaning widespread flash floods are expected and moderate risk, meaning numerous flash floods are likely. 

Fort Bragg, Willits, Laytonville, Leggett, Covelo and Westport are high risk for flooding.  

Point Arena, Gualala, Anderson Valley, Ukiah, Talmage and Hopland are under moderate risk.  

The Garcia River in southern Mendocino County has already flooded, having reached 10 feet (the usual “it’s going to flood” soon height) around 3 a.m. this morning. By noon it had reached 13 feet and by 12:30 p.m. state Route 1 was inundated with flood waters, and the road was closed between Point Arena and Manchester. No estimated time of reopening has been provided by Caltrans. Learn more here. 

The Navarro River in Navarro and Russian River in Hopland are expected to reach minor flood stages, said the weather service.  

The Russian River is likely first, forecast to hit minor flood stage tonight, according to the National Oceanic and Atmospheric Administration. The Navarro River should reach flood stage by 6 a.m. Friday, said the administration. 

It’s not too late to prepare for possible flooding. Find a list of sandbag stations here.