Series of storms expected starting Wednesday

Balmy holiday weekend weather will give way this week to something more typical for the time of year and welcome to those watching the state's water reserves.

Beginning midday Wednesday, a series of storms are expected to roll through the Yuba-Sutter area, dropping as much as four inches of rain through Sunday, according to the National Weather Service's Sacramento office.

"The storm track is right over us," said forecaster Johnnie Powell, adding these storms will bring mostly light rain with occasional heavier rain, and winds of up to 35 to 40 mph.

Combined, the wind and rain will probably take down some older trees and raise the chances of small-scale flooding along creeks and streams, Powell said. The National Weather Service issued an advisory on Monday afternoon saying small amounts of flooding might also be seen from weirs and in bypasses.

However, because the storms derive from the south Pacific Ocean rather than the Gulf of Alaska, they will drop a lot more rain than snow, with the latter not falling much, if at all, below 7,000 feet.

But David Rizzardo, the chief of the snow survey section for the state Department of Water Resources, said a warmer storm in late November is actually not unusual, and not a large concern in terms of adding to the state's snowpack.

"It's too soon for it to make much impact in runoff," he said. "In December, January, February is when we really expect to build most of the snowpack."

There is room in reservoirs such as Lake Oroville for whatever rain does fall, he said.

"If this actually happens the way it's forecast, in the Feather River watershed we'll have three to four times the normal precipitation for this time of year," he said.

And the important impacts of early storms are not in the mountains as much as they are on the routes runoff water will eventually take.

In dry years, the ground will absorb more runoff when snow begins to melt, Rizzardo said, so if storms like this one saturate the ground, there will be more flowing into reservoirs later if it is an otherwise normal rainfall year.

Whether the winter of 2012-13 will have the typical amount of rain is still unknown. But Powell said while long-term forecasts beyond Sunday are not clear, the weather pattern looks to remain unsettled.

CONTACT Ben van der Meer at bvandermeer@appealdemocrat.com or 749-4786. Find him on Facebook at /ADbvandermeer or on Twitter at @ADbvandermeer.