Short Version: Yes, We Need More Rain

shasta lake reservoir water supply
Shasta Lake, California's largest reservoir, is at about 62 percent of average for this time of year. (Molly Samuel/KQED)

The system that just passed through Northern California brought a decent "wetting," a glimmer of hope and put a damper on the wildfire season. But you're familiar with the term: "a drop in the bucket?"

For a rough gauge of how the state is doing, water managers keep a close eye on a network of eight recording stations in the northern Sierra, between Shasta and Tahoe. Right now those stations are reporting about 2 and a half inches of precipitation for October and November, or just about a third of what's considered "normal" for this date.

"It's gonna be hard to make that up," says Maury Roos, chief hydrologist for the state Department of Water Resources. If we don't, Roos says he'll be ready to invoke the dreaded "D-word." Roos says a second straight dry winter "would put us into what I would consider drought--a real hydrologic drought. I don't think we've reached that threshold yet."

There is time to catch up. Typically the state gets about half its annual precipitation during the coming two months, December and January. Last year we had a soggy December and then the tap simply shut off, leaving us with an epic dry spell from January through March and overall, a "wet season" that failed to fully recharge key reservoirs. That means that another winter on the dry side would leave us without the "carry-over" storage that helped Californians through this past summer.

Sadly, the chances of that seem pretty good. The winter outlook just released by NOAA's National Climate Prediction Center shows the odds in favor of "persistent or intensified drought" for nearly all of California, through February.

Current models seem to favor another dry winter for California. (NOAA)
Current models seem to favor another dry winter for California. (NOAA)

There's been a lot of talk already this fall about whether California is in a "record-dry" year. Peter Gleick of the Oakland-based Pacific Institute breaks down that discussion in his latest post. As usual, the answer is: it depends on what you're counting. But Gleick isn't waiting around for any official declarations to roll out the D-word:

California is in the midst of another severe drought, measured as the weighted average of precipitation around the state. Indeed, the past two years have both been very dry.

More troubling, writes Gleick, is the long-term trend, which shows flagging precipitation despite California's wild annual fluctuations.