Atmospheric river doesn’t quench drought

Another atmospheric river pummeled Northern California over the weekend and into Monday, but Sonoma Valley was spared the worst of it, said a meteorologist from the National Weather Service.

The storm system brought between 2 and 3 inches of rain to Sonoma Valley over the weekend, according to Jeff Lober, a NWS meteorologist, with some “especially significant” rainfalls in the hills and mountains of Sonoma.

“We’ve been tracking this since early last week,” Lorber said of the storm. “We’ve been anticipating heavy rainfall and rather strong winds that are accompanying.”

Sonoma Valley was once again spared, with wind speeds between 30 and 40 miles per hour while Mt. Diablo near Walnut Creek saw gusts up to 50 miles per hour, Lorber said.

Fire Chief Steve Akre said that only one crash came from the storm and the incident resulted in no injuries.

Akre urged drivers to drive cautiously, “anytime the roadways are wet.”

This atmospheric river was different from the one seen in October, which pelted Sonoma Valley and other North Bay cities with more than 4 inches of rain.

“It’s comparable, but the focus of it is more toward Santa Cruz southward,” Lorber said. “The North Bay definitely bore the brunt of the October system.”

And while Sonoma may not have seen the most rain, it is far outpacing the rain fall totals recorded during the last two years of extreme drought.

Sonoma has seen 8.03 inches of rain since the beginning of this season compared to 1.53 inches this time last year, according to Accuweather.

But that doesn’t mean the drought it over.

“This is getting us back to where we need to be, but it’s still the start of rain season,” Lorber said. “This snow pack’s going to be very beneficial for keeping that moisture up there... that provides consistent drain into the basins and soils.”

Sonoma Water, the county’s water agency, shows that the region’s two main reservoirs, Lake Sonoma and Lake Mendocino, are both well below the water capacity levels seen in 2019 and 2020.

“We are going to need a lot more of these types of storms to get out of this drought,” said Barry Dugan, a spokesperson for Sonoma Water.

Lake Sonoma has gained 2,000 acre-feet of water since Saturday, but more is expected as rain runoff flows into the two reserviors, Dugan said.

“These are positive storms, they’re beneficial — but it’s a start,“ Dugan said. ”We’re in a record-setting drought... and until we see the storage in Lake Sonoma really rebound and the storage in Lake Mendocino rebound, we’re not in a position to say we’re out of the woods.“

So far, Sonoma has received double the amount of precipitation typically recorded since the rainy season began on Oct. 1, Dugan said. But the overall amount of rain that fell during the 2021 calendar year is less than half of what’s seen in an average year.

As of Dec. 9, Lake Sonoma was at 49% capacity and Lake Mendocino just 36.3% capacity. In contrast, just two years ago, Sonoma was at 86.8% capacity and Mendocino was at 97.3%.

The weather is expected to clear up toward the end of the week, according to Accuweather. But not before another helping of rain arrives on Wednesday, when nearly an inch of moisture is expected to fall.

Contact Chase Hunter at chase.hunter@sonomanews.com and follow @Chase_HunterB on Twitter.