El Nino Storm Expected in Southland

El Nino isn’t done, yet.

Rain, thundershowers and--yes, in May--even some snow are expected to fall on Southern California today, and meteorologists say the much-discussed climatic phenomenon is at least partially responsible.

Kevin Stenson, a meteorologist with WeatherData Inc., which provides forecasts for The Times, said the storm due in this morning is a cold one that spent much of its formative youth over the chilly waters of the Gulf of Alaska.

Normally at this time of year, such storms move inland well north of California, traveling east on powerful, high-altitude jet stream winds that cut across British Columbia and the Pacific Northwest.

This week, however, thanks largely to El Nino, the jet stream is split, with one branch following the usual track and the other barreling south along the Pacific Coast before heading inland through California.

Tuesday’s storm is riding this southern branch, and Stenson said Los Angeles residents can expect between one-tenth of an inch and an inch of rain--depending on where they are--before the inclement weather moves out to the east sometime late Wednesday or early Thursday.

He said several inches of snow will fall at altitudes above 5,000 feet in the Tehachapi, San Gabriel and San Bernardino mountains.

“The precipitation will start about dawn on Tuesday, with scattered showers through the afternoon,” Stenson said. “There’s enough extra energy in the system for a pretty good chance of thunderstorms in the afternoon and evening.”

Unlike winter storms, which usually include fairly prolonged periods of steady rain and snow, today’s spring storm will produce spotty precipitation, Stenson said.

“You could be in one place where they get a lot of rain or another, close by, where they get hardly any,” Stenson said.

He said the scattered showers should continue through Wednesday, with a continuing possibility of isolated thundershowers through Wednesday night and a chance of a lingering sprinkle or two Thursday morning.

After that, it should get warmer and drier through the weekend, with partial cloudiness and high temperatures from the upper 60s to the mid-70s.

That’s the way the weather is supposed to be in Los Angeles during May, but this has been a soggy spring.

Normally, during May, the Civic Center gets about a third of an inch of rain, but with less than half of the month gone, it already has gotten 1.03 inches.

A year ago, National Oceanographic and Atmospheric Administration meteorologists predicted that because of El Nino, Los Angeles would get about twice the normal amount of rainfall this season, which runs from July 1, 1997, through June 30, 1998.

Thus far, the total for the season is 28.94 inches, just about double the normal total for the date of 14.67 inches.