El Nino prime culprit for severe weather in California

A storm system that has battered California for three days, flooding streets and triggering mudslides, is now aiming at Arizona.

This bout of bad weather, say meteorologists, is largely courtesy of El Niño, which is expected to influence the jet stream throughout the winter months.

In southern California on Wednesday, the third storm in three days brought high winds and continuous rainfall, prompting authorities to issue flash-flood and high-wind warnings. In the north, some 30,000 people lost power, and the state’s highway patrol reported numerous mudslides along roadways.

On Thursday and Friday, Arizona is expecting as much as four feet of snow in the northern part of the state and heavy rainfall in the center. And Nevadans should prepare for flooding later this week, officials in Las Vegas said. That city was pummeled with heavy rains Tuesday.

“It’s going to be a big one,” says Darren McCollum, lead forecaster in Flagstaff, Ariz., for the National Weather Service.

While it’s difficult to pinpoint what’s responsible for a batch of severe storms, many are pointing their finger at El Niño.

“El Niño appears to be showing signs here in this pattern with particularly strong disturbances within the jet stream,” says Greg Carbin, a meteorologist at the National Weather Service’s Storm Prediction Center in Norman, Okla. “The intensity of the mid-level and upper-level winds has been quite dramatic.”

The high winds, which reached 60 miles per hour and toppled power lines in Sacramento and Silicon Valley in California on Wednesday, are expected to taper off as storm systems move east and into Arizona.

While El Niño has already produced big storms across the West, it may also be blamed for producing an unimpressive amount of snowfall for the upcoming winter Olympics in Vancouver, British Columbia.

As The Seattle Times notes, El Niño years can bring both stormy weather as well as warmer temperatures.

In San Francisco, El Niño has been held responsible for the relocation of the city’s sea lions from their Pier 39 home to colder waters along the Oregon coast.

"My gut feeling is it has something to do with the [ocean-warming] El Nino conditions off California, which is driving prey and sea lions up north," Kim Raum-Suryan, a biologist at the Hatfield Marine Science Center in Newport, Ore., told USA Today.

But while most meteorologists say that El Niño is at the root of this week’s rotten weather, some disagree.

On his Sciencedude blog for The Orange Country Register, science writer Gary Robbins interviewed William Patzert, a climatologist at the Jet Propulsion Laboratory in Pasadena, Calif.

“While the rest of the country has been battered by strong, cold outbreaks; bringing storms, snow and frigid temperatures over the past two weeks, California remained mild and dry. Now it’s our turn,” wrote Mr. Patzert in an e-mail to the science dude.

But don’t blame it on El Niño, he says.

“The El Nino warmed subtropics might be pumping a little moisture into these storms as they move south and could be giving rain and snowfall totals a boost. But not much!” he wrote.

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