The National Weather Service Climate Prediction Center on Thursday updated one of its most forward-looking, long-range forecasts, and the picture is good for drought-plagued California.
The forecast now indicates all of California is likely to see above-normal precipitation in the January to March period. These are normally the wettest months of the year — exactly when the state needs heavy rain and snow to make a dent in the drought.
“I’m quite optimistic that the entire state is going to get hosed,” Bill Patzert, a climatologist with NASA’s Jet Propulsion Laboratory, told the Los Angeles Times.
But the forecast also indicates temperatures will be warmer than normal, which could mean most of that precipitation falls as rain, not snow. This is less than desirable.
If rains are heavy, warm storms could still refill reservoirs significantly. But a poor snowpack would mean there is less snowmelt to refill those reservoirs as they are drawn down next summer. This combination might mean the drought continues, even despite heavy rains in winter.
One reason is the El Nino weather phenomenon growing across the Pacific Ocean. This periodic warming of the equatorial ocean often produces wet winters in California. Recently, its timing has shifted a bit later into winter, and it has also strengthened. For instance, unlike earlier forecasts, there is now no expectation of heavy rains during the month of December.
However, all that rain does not guarantee floods. It’s a possibility, but not a sure thing. In fact, El Niño years typically don’t bring the massive “Pineapple Express” storms that have caused some of California’s worst natural disasters.
“These big El Niños, even though they have given us really wet years, didn’t translate into really killer floods,” Michael Dettinger, a research hydrologist at the U.S. Geological Survey, said at a recent “El Niño Summit” hosted by UC Davis.
Top image: This new long-range forecast image indicates that virtually all of California is likely to see wetter-than-normal conditions January through March. (National Weather Service Climate Prediction Center)