The calendar tells us it should be looking a lot like Christmas out there, but the North Bay's run of dry, cool and sunny weather invokes a mid-fall sensibility.

Since July, Santa Rosa has had about half the typical annual rainfall of 8.34 inches, only 4.15 inches as of Dec. 13.

"Our ground-water aquifers aren't filling up. The creeks aren't running like they should," Santa Rosa Fire Battalion Chief Mike Jones said.

The pattern produced temperatures below freezing on Tuesday and prompted firefighters to conduct a late-season controlled burn last week because the paltry rain totals.

That may change Thursday when showers are forecast to bring an end to the three-week dry spell and bring a little snow to the Sierra.

Clouds are due tonight. They'll bring a slight chance of showers by midnight and a strong chance of showers by Thursday morning, said Diana Henderson, a meteorologist for the National Weather Service.

"Not a dousing. It'll be quick. Friday it'll be back to partly cloudy," she said.

It's far too early to talk about drought-like troubles. Winter doesn't officially begin until next week. And a string of winter storms that began lining up in November 2010 and continued through the season made the 2010-2011 water year one of the wettest in decades.

That eases some of the pressure now. The lack of rain so far is not a concern in terms of the water supply, said Brad Sherwood, spokesman for the Sonoma County Water Agency.

Water levels at the agency's two main reservoirs, Lake Sonoma and Lake Mendocino, remain above average for this time of year, and the bulk of the year's rainfall doesn't come until February.

For those planning to spend the holidays in the Sierra, there is a chance for a white Christmas. The forecast this week included a 20 percent chance of snow on Thursday, with a high of 39 degrees around Lake Tahoe.

Beyond that, sunny skies are predicted through Monday.

This cold, dry weather was getting a little old for Santa Rosa Junior College student Matthew Hartley.

On Tuesday afternoon he was at Santa Rosa Ski and Sports with his girlfriend, who was looking at new ski boots. Hartley was hoping Thursday's storm would bring snow in the Sierra.

"We're going Friday," Hartley said. "Definitely."

While longing for last year's early snow season, Max McCormick, back-shop manager at the sporting goods store and a shop employee since 1999, said this year is more typical.

"You can't compare it to last season. By this time we had 10 feet on the ground," he said.

Conditions at ski resorts Tuesday ranged from still closed to open with limited runs of man-made snow. Resort web cams showed some ski trails still available for hiking, some with thin layers of snow and rocks in view and others with thick white snow bases.

At Northstar ski resort near Lake Tahoe's north shore, 12 lifts were running Tuesday.

"We're not really worried about it yet. The snow-making has been fantastic," said spokeswoman Jennifer VanPernis. "It's one of the reasons we invest in snow-making equipment."

You can reach Staff Writer

Randi Rossmann at 521-5412 or