As of 4 p.m. Tuesday, the National Weather Service had recorded 17.4 inches of rain this season at Charles M. Schulz-Sonoma County Airport, 145 percent of normal.

The result has sent fire departments and road crews out into the elements to deal with fallen trees, debris slides, flooded roads and gaping potholes like the one that reduced southbound Highway 101 to a one-lane nightmare Monday.

Trees fell throughout the county Tuesday, with several falling across Highway 1 near Sea Ranch. Forecasters had said Tuesday's storm would bring 0.5 to 1.5 inches of rain.

So far, the soggy season has come without the worst aspects of a wet Sonoma County winter — severe flooding and mudslides.

The county is subject to both forms of disaster — in 2006, a torrent of rain on New Year's Eve flooded Petaluma, Guerneville and Napa, causing hundreds of millions of dollars of damage.

In 1998, 12 inches of rain in a week set off a mudslide in Rio Nido that destroyed 24 homes and caused about $10 million in property damages in the Russian River community.

But Mother Nature's recent timing has spared the area such fury even as Southern California has suffered. Local rainfall this winter has been separated by enough time for land to drain and rivers to carry away extra water.

"If we didn't have these breaks, we'd probably be more worried," said Brad Sherwood, spokesman for the Sonoma County Water Agency.

Tim McCrink, a senior engineering geologist at the California Geological Survey, said the pattern of rain and respite also has been good for the stability of hillsides.

"We are not seeing a lot of landslides right now because we keep having two- and three-day breaks between the storms," he said.

That alternating pattern of storm and calm may change later in the winter, but it appears to be holding for now. AccuWeather is forecasting spotty showers today, but no more rain again until Saturday, when another quick-moving storm begins to pass through.

"There will be another little drying-out period there," said Diana Henderson of the National Weather Service.

Still, some consequences of the wet winter may take longer to appear, McCrink said.

Sonoma County is prone to two types of landslides, he said: Shallow slides, which send a torrent of liquefied debris down a slope, and deep landslides, which move larger chunks of land en masse.

The shallow slides are often triggered by a string of intense storms, the kind the area has avoided so far. But the deep slides may occur even if such storms don't materialize. When rainfall saturates into the bedrock, it can reduce the friction holding a landslide-prone area in place, moving the land.

A deep landslide may move a 50-foot-deep section of land 10 feet down a hill, much less distance traveled than by a shallow debris slide, he said. But if it occurs on a populated area, the deep slide can do major property damage, McCrink said.

The chances of a deep landslide, which can occur months after the rains stop, have increased in Sonoma County because of the wet winter, he said.

"I would give a high probability of several occurring this year," he said.

You can reach Staff Writer Sam Scott at 521-5431 or at sam.scott@pressdemocrat.com.