Motorists skidded, slipped and crashed along slick Sonoma County roads Monday during a storm that brought about a quarter-inch of rain, National Weather Service meteorologists said.

Many grape growers spent the day resting, exhausted from an all-out effort over the weekend to bring in their crop before the storm hit. But they will have to wait a while longer for dry, warmer weather to dry out their vineyards and resume the harvest.

A stronger storm was expected to arrive at about midnight Tuesday and dump at least another half-inch of rain on the region.

The first winter-like storm of the season caused havoc on local roads.

Most of the 30-plus crashes handled by CHP officers Monday were caused by motorists driving too fast for the rainy conditions, CHP Officer Jon Sloat said.

Two people suffered moderate injuries in separate crashes in Rohnert Park and Graton, Sloat said.

In Occidental, 884 customers were still without power late Monday due to a downed line reported at about 1 p.m., PG&E spokesman JD Guidi said.

Power was knocked out for more than 1,000 customers in the Roseland area of Santa Rosa at about 6 p.m. when a vehicle crashed into a utility pole. Power was restored to all but 51 customers by nightfall, PG&E said.

Monday's weather system, which stretched along much of the West Coast, had nearly petered out by nightfall.

"It's an early-season rain for us," meteorologist Chris Stumpf said.

Partly cloudy skies and temperatures approaching 70 degrees were expected for much of Tuesday before another storm arrives from the Gulf of Alaska by midnight.

Grape growers scrambled all weekend to get the fruit off the vines, especially chardonnay and zinfandel grapes, which are more susceptible to damage from the rains.

As much as 30 percent of the county's grape crop is now in wineries' tanks, estimated Nick Frey, president of the Sonoma County Winegrape Commission.

"It's hard to know when it's moving so fast," he said. "Everyone was pushing hard from about last Wednesday or Thursday."

Last week, Frey had estimated that about 20 percent of the crop would be harvested by the end of the weekend, but the threat of heavy rains sent everyone into top speed.

"We picked every single night and every day, all week long, until this morning," said Bret Munselle, owner of Munselle Vineyards, which farms about 250 acres in Alexander Valley. "It has been a super busy and condensed harvesting."

His company picked 80 percent of its crop of white grapes in the last week. But 5 or 6 tons of zinfandel grapes remain on the vine. "Those are the ones we are most worried about," Munselle said.

Growers are hoping for a break in the weather to help dry the grape clusters, canopies and the soil. In the meantime, they're catching up on rest, and wineries are getting a chance to turn the tanks.

"The key is what it does if we get a little wind and a break tomorrow," Frey said. "But I hear we're getting more on Wednesday. It's probably something we could have lived without."

The rain should move east to dump snow on the Sierra and leave behind sunny skies over Sonoma County for the weekend, Stumpf said.

Motorists heading to the mountains should bring tire chains, waterproof clothing and a full tank of gas, CHP officials said.

And don't forget your umbrella or rain coat.

On Monday, John Sawyer took shelter under a Santa Rosa Plaza awning. The Santa Rosa man had forgotten to pull his raincoat and boots out of the closet when he left on bicycle earlier in the day, and his feet were soaked.

"I'm not tripping over it," Sawyer, 39, said. "We probably needed the rain."