Washington's upcoming winter, ski season: Wet, dry; who knows?

With rain and wind expected to smack the Puget Sound region today, fall has arrived and winter's not far behind. But this season probably won't bring a repeat of the snow bonanza that delighted skiers and snarled Interstate 90 last winter, according to the National Weather Service (NWS) in Seattle.

The strong La Niña pattern that intensified storms in 2007-2008 has dissipated, NWS regional science officer Kirby Cook said Wednesday. "Relative to last year, it's likely we'll stay a little drier this winter," he said.

But there's also no sign of the El Niño conditions that usually bring an exceptionally warm and dry winter to the Pacific Northwest.

That leaves the region in a kind of meteorological limbo, where it's very hard to predict how the upcoming season will play out, Cook said.

"We can have crazy weather here anytime."

Computer models suggest temperatures might be slightly warmer than usual this winter. But when it comes to rain and snow, the models are deadlocked: They show equal odds it will be wetter or drier than usual.

But that doesn't mean the weather will be bland, Cook cautioned. Some of the region's biggest floods and windstorms have hit in years when there is neither an El Niño nor La Niña.

"We could see a fairly significant amount of severe weather," he said.

The local weather-service office issues a "seasonal outlook" every fall, to help governments, utilities and others prepare for the coming winter. But the accuracy is not very impressive, said University of Washington meteorologist Cliff Mass.

"Unfortunately, our skill in doing these kinds of forecasts is relatively marginal," he said.

For example, the weather service's seasonal outlook did not foresee the heavy snowfall that slammed the region last winter, closing Snoqualmie Pass for days and breaking records in some ski areas.

Seasonal forecasts are usually more accurate in El Niño or La Niña years, because meteorologists understand fairly well how those strong patterns affect the weather in the Pacific Northwest, Mass explained.

Even though the outlook is unclear, Puget Sound Energy is preparing for trouble, said spokesman Andy Wappler. Storms in December 2006 knocked out power to 75 percent of the utility's customers, with some in the dark for up to 11 days.

Over the past year, PSE spent $12 million on tree trimming and invested nearly $250 million in new or rebuilt substations, new power poles and Teflon-coated power line less likely to snag falling branches, Wappler said. Many of the improvements were concentrated in East King and Kitsap counties and on Whidbey Island, where outages are most common.

PSE has also added an online service that will allow customers to key in their ZIP codes and get outage reports and repair schedules.

The Washington Department of Transportation is preparing for winter, too, with plans to quickly move equipment and personnel to weather hot spots in advance of storms, said spokeswoman Alice Fiman. The agency is also experimenting with new ways to get out traffic updates, including Twitter channels and updates on Facebook and MySpace.

Last winter, when snow and avalanche hazards closed Snoqualmie Pass for nearly 150 hours, DOT's Web site was deluged with 14.5 million hits in one 24-hour period.

Sandi Doughton: 206-464-2491 or sdoughton@seattletimes.com