Fox News Weather Center

El Nino to drive flooding rain, mountain snow into California this week

A series of El Niño-enhanced storms will continue to bring more beneficial rain and snow along with hazards to California and the southwestern U.S. in absence of a pineapple express.

The above-average temperatures in the tropical Pacific Ocean, known as El Niño, tend to strengthen the storm track into the West Coast and occasionally California during the winter.

Train of storms rolls into California

The current El Niño has tied the strength of the El Niño during 1997, which was the strongest on record.

The storms which initially brought rain, snow and ice to much of the Pacific coast of the United States to start the week will spiral progressively farther south into Friday.

According to AccuWeather Senior Meteorologist Ken Clark, "The first El Niño-enhanced storms of the year will bring soaking rain and heavy mountain snow before winding down on Friday."

California storms to cause travel delays and raise flood, mudslide risk into Friday

Travel along the major highways in California will be hampered by heavy rain and mountain snow, including interstates 5, 8, 10, 15, 40 and 80.

Water will collect in areas that drain poorly on area roads. Intersections, curves and highway ramps will be especially slick.

Enough rain and low cloud ceilings will lead to airline delay in San Francisco and Los Angeles.

Through Friday, the total rainfall from the storms will average 2-4 inches along the California coast with locally 6-10 inches along the west and southwest-facing slopes of the coast range.

This sort of rainfall, while not extreme as the biggest El Niño year storms, will be enough to cause incidents of flash and urban flooding, as well as mudslides and other debris flows.

The storms will be significant enough, without the presence of a steady stream of tropical moisture feeding in, often referred to as a pineapple express or pineapple connection, Clark stated.

"The likelihood of the events will increase as the week progresses until the last of the big rain-producing storms pushes inland on Friday," Clark said.

The storms will translate to big snow for the Sierra Nevada, especially the southern part of the mountain range.

"Above 7,000 feet, snowfall will be 2-4 feet over the Sierra Nevada with 3-6 inches of snow down to about 4,000 feet," Clark said.

The biggest storm of the series will affect California during Wednesday into Thursday, before turning inland.

"Snow levels will lower Wednesday through Thursday with the big storm," Clark said. "That's when the elevations between 4,000 and 6,000 feet will receive the bulk of their snow this week."

Enough snow could fall on Cajon and Tehon passes to make for slippery travel by Thursday.

While winds will be not be excessively high, they will be strong enough to direct damaging waves toward Southern California later Wednesday through Thursday.

Some of the waves will be high enough to top jetties and cause flooding along some beach communities.

The rainfall, but especially the mountain snow, will be money in the bank for easing the drought situation going into the dry season next summer.

Some of the rain and melting snow will be absorbed by the dry ground, but some of it will also run off and begin to fill reservoirs and lakes.

In the short term, the ski season will be the best in years for California and much of the West.

Rain, snow to push across US

While the storms will tend to weaken as they pass the Sierra Nevada, they will still pack enough moisture to bring areas of significant rain and mountain snow farther east.

Up to a couple of feet of snow will fall on the mountains of Arizona, the Wasatch Range in Utah, the San Juan mountains in Colorado and New Mexico, and the southern Rockies in general.

Motorists traveling along I-25 and I-40 should be prepared for periodic delays and possible road closures through Friday.

The storms will also bring rounds of quenching rain to the desert areas including the cities of Las Vegas and Phoenix.