Giant storm heading our way (w/video)

A storm heralded as Herculean is expected Wednesday night, with 8 inches or more of rain predicted for California’s coastal mountains and up to 5 inches forecast to fall on lower parts of Sonoma County.

There hasn’t been a storm of such ferocity since 2008 when four inches of rain drenched Santa Rosa and fierce winds knocked out power to 1 million California residents.

The National Weather Service has issued multiple warnings to residents and travelers of the likelihood of creeks and roadway flooding, hours of sustained, powerful winds and power failures from falling trees onto lines into Thursday night.

“It looks like the strongest storm in several years, since January 2008,” said Austin Cross, meteorologist for the National Weather Service in Monterey - referencing the whopper three-day storm of almost seven years ago. “People need to be prepared.”

It’s due in Wednesday night through Thursday night as it moves south through the Bay Area and down the state. ?“We’re expecting pretty strong winds, 30-40 mph, and gusts to 50 mph,” Cross said.

Rainfall should reach?3-5 inches in Sonoma County valleys and go higher with elevation. That will push the area above typical rainfall amounts for this time of year, yet fall far short of bringing enough to end the state’s three-year drought.

“I keep hearing it’s going to be a big one,” said Rob Silva, road maintenance division manager for Sonoma County. “We’ll be prepared for it, as prepared as possible.”

While a light rain fell Monday, road crews cleared debris from culverts and under bridges and filled potholes in preparation of the storm. That work was expected to continue Tuesday and Wednesday, stopping a few hours before the storm is due.

Also out troubleshooting Monday were PG&E workers and Cal Fire crews, clearing brush in sensitive areas. Area firefighters were watching, too. Those whose areas include a river or creeks have their water rescue equipment ready.

“We’ve got our swift-water rescue equipment out and we’re prepping our boat,” said Mike Stewart, acting captain for Ukiah Valley Fire.

While Lake Mendocino remains well under normal water levels, Ukiah city and valley firefighters are anticipating creeks heading into the Russian River could rise appreciably from the storm, although not as much as coastal creeks, Stewart said.

When the storm hits, about ?50 Sonoma County road workers will chase storm damage - mainly falling trees blocking roadways and debris-clogged culverts causing roadway flooding.

PG&E spokeswoman Brittany McKannay on Monday also said her company was mobilizing people and command centers in anticipation of a major storm.

Petaluma schools, which saw two of its high school band rooms flood last week at Casa Grande, are preparing for the deluge at all campuses by clearing storm drains and ditches and providing sand bags.

“Right now our grounds crew is making sure all the safe checks are in place,” said Superintendent Steve Bolman.

Last week’s flooding at Casa Grande happened when drains became clogged, he said. The district always checks problem drains before big storms, but that particular drain had never before been a problem.

“Now it will be checked every time,” he said.

The musical instruments escaped the flooding unscathed, but the carpet and lower walls were damaged, requiring both to be replaced. Bolman estimated the rooms wouldn’t be back open until after Christmas break.

With word spreading of the storm’s potential, business was increasing at area hardware stores.

“Everybody’s getting ready. We’re doing a lot more business with sandbags and filled sandbags. Some people (expect) incredible runoff and are barricading the runoff from their house and garage,” said Steve Glenn, a manager at Sebastopol Ace Hardware. “Lots of rain gear is going out, boots and all that.”

Storm supplies Monday still were full at the northern Sebastopol store. Another shipment was due in on Thursday “of all that kind of stuff,” Glenn said. “We’ll bulk up this next order for tarps and be as prepared as everyone.”

While this possible-monster storm will soak an area from southern Washington to Southern California, the bulls-eye is on Northern and Central California.

“It’s coming at just the right angle, right through Central California and down into Southern California” where 1-3 inches of rain is expected, Cross said.

Over the North Bay, it should linger for more than 24 hours and taper to showers on Friday. The weekend looks to offer a short dry spell as another storm prepares to roll into the area.

It’s due in late Sunday night into Monday and shouldn’t be as strong as this week’s “but still could potentially bring a pretty good dose of rain,” Cross said.

The parched region now is nicely soggy from a recent run of rain. Santa Rosa currently is about 0.4 inches below average for this time of year, with?7.21 inches.

“This should catch us up to normal and probably a fair bit beyond normal,” Cross said, adding that even with the impressive rain due, the state’s reservoirs will need much more to reach normal levels.

But heavy runoff is expected. It could rain hard enough to bring almost an inch of rain in an hour, overwhelming creeks and ditches causing flash floods, said Brian Edwards, meteorologist with AccuWeather.

The North Bay’s last major storm was Feb. 7 and 8 when?4.88 inches of rain fell in Santa Rosa. “That would be comparable rainfall-wise,” to this storm, Accuweather’s Edwards said.

But that storm had winds of 25-30 mph and so should fall short of what is anticipated Wednesday night.

That’s where the comparison shifts to the 2008 multiday storm, Cross said.

On Jan. 4, 2008, a storm struck that started an 11-day run of rain. For the first three days it included winds gusting to more than 70 mph in the Bay Area, near-record rainfall and power cut to more than 1 million residents statewide.

Locally, winds gusted to 49 mph at the Charles M. Schulz-Sonoma County Airport, toppling trees, which knocked out power to 55,000 PG&E customers from 600 different power failures in three counties. Santa Rosa received 3.8 inches of rain while some higher elevations, including the hills above Healdsburg and Cazadero, got 7 and 8 inches.

With headlines touting the historic potential of the coming storm, county road boss Silva offered a reminder of weather’s capriciousness.

“The last one was supposed to be big and ended up in the South Bay,” he said.

You can reach Staff Writer Randi Rossmann at 521-5412 ?or randi.rossmann?@pressdemocrat.com.