Sunday, February 21, 2016

Whatever happened to El Niño?

I went running in Marin Headlands yesterday. The formerly brown hills have greened up a bit, but there's no sense they are bursting with new life. And there's almost no mud on the trails. In past El Niño years, I remember dodging through sections where a wrong step would have caused me to lose a shoe to the muck.

Some weather commentators continue to insist this season is "one of the most powerful El Niño events on record." In Northern California, precipitation, while not heavy, was at least close to "normal" -- that is, to pre-drought levels. But in SoCal, it simply hasn't rained. The first 15 days of February were completely dry. CBS Los Angeles asked NASA climatologist Bill Patzert, who had labeled what was coming the "Godzilla" El Niño last fall, for an explanation.

"El Niño remains immense," Patzert insisted to CBS News. "It's had a powerful impact over the last six months, and even this winter, all the volatile weather we've had across the United States -- the fingerprint of El Niño is on all these events."

Turns out the El Niño is so big, it shifted the jet stream further north, allowing storms to batter Northern California and the Pacific Northwest.

But the northern storms are also dramatically boosting California's snow pack -- now the deepest it's been in more than a decade. Spring snow melt will help fill the state's depleted reservoirs and provide 30 percent of California's water supply.

Weather watchers still hope El Niño will dump more rain in the North and finally get to the South -- but so far, he's a bit of a bust.

And other federal scientists fear California has missed its chance.

Forecasters now say conditions are likely to flip to their opposite phase, known as La Niña by late summer or early fall, which could set the stage for another drier-than-normal winter and prolonged drought in California.

“We are reasonably confident that there will be a La Niña,” says Huug van den Dool, seasonal forecaster at NOAA’s Climate Prediction Center, “but we plead ignorance as to whether this is going to be a small, moderate, or strong La Niña.”

Just as the stronger El Niños tend to favor wetter winters in California, the mirror-image La Niña is sometimes a harbinger of drought. Strength is measured by how much ocean waters deviate from their normal temperatures. Warmer waters provide more moisture to brewing Pacific storms, while colder waters tend to dry things out.

I guess we'll just have to wait and see.

1 comment:

joared said...

Yeah, we've been getting only token rain here in L.A. area. Now it's getting warmer than warm for another week or so.