Storm Blasts Orange County, More Rain Coming

ORANGE COUNTY, CA — The first in what is expected to be a series of storms rolled through the Southland Monday, dumping rain across the region and raising fears of mudslides in recent burn areas, while dropping enough snow to close the 5 Freeway through the Grapevine.

The Orange County Sheriff's Department issued a voluntary evacuation order for neighborhoods near the Holy Fire burn area, noting that "flooding and debris flows are possible and evacuation routes can quickly become impassable."

Sheriff's officials said the heaviest rain was expected in the burn area Monday afternoon through about 7 p.m. The voluntary evacuation order "is a precautionary measure and there are no road closures at this time," sheriff's officials said shortly before noon.
A flash flood watch was in effect in Orange County for coastal, inland and mountain areas.

"Heavy rainfall of 1 to 2 inches, with localized amounts up to 3 inches along the coastal slopes, is forecast to occur," according to an NWS statement forecasting Orange County conditions. "Rainfall amounts of one half to one inch could fall in one hour, with the heaviest rates occurring near the coast.

"There is the potential of mud slides and debris flows at recent burn scars, particularly near the Holy Fire burn scar. Debris flows can happen suddenly with little time to act. Heed the advice of local officials. In addition, street flooding is possible along with the possibility of some road closures."

Early Monday morning, the National Weather Service issued an Urban and Small Stream Flood Advisory for much of Orange County and western Los Angeles County due to the persistent rain falling in the area. That advisory was allowed to expire at 9:30 a.m.

Monday's storm was expected to produce between a half-inch and 1 1/2 inches of rain and up to 2 1/2 inches in the mountains and foothills, NWS meteorologist Todd Hall said. Two more storms are expected to roll through the area this week, generating between 3 and 6 inches of rain in coastal valleys and 7 to 9 inches in mountains and foothills, he said.
"It's going to be a very wet week for Southern California," Hall said.

Forecasters said rain was expected to taper off Monday evening, giving us a short break until Tuesday afternoon, when a potentially more potent storm moves in.

"This one may be the strongest of the week, with a strong southerly component to the low level winds and good instability, especially in the afternoon," according to the NWS.

A winter storm warning denoting potentially perilous conditions will be in effect in the San Gabriel Mountains until 10 a.m. Tuesday, according to the NWS.

Heavy snow is expected, with snow accumulation of 6-12 inches anticipated above 5,000 feet and 1-3 inches between 4,000 and 5,000 feet, according to the NWS. There also could be light slow accumulation down to 3,500 feet, which could affect Interstate 5 through The Grapevine.

At the same time, "damaging" winds of 25-35 mph gusting at up to 60 mph will buffet the northwest San Gabriels, including the Interstate 5 corridor, the weather service said. But no other warnings of high winds were issued for any other part of L.A. County early Monday morning.

"Plan on difficult travel conditions, including during the evening commute on Monday and the morning commute Tuesday. Be prepared for significant reductions and invisibility at times," according to the NWS statement discussing mountain conditions. A Winter Storm Warning for snow means severe winter weather conditions will make travel very hazardous or impossible.

"If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. The latest road conditions from Caltrans are available by calling (800) 427-7623."

Along the Orange and Los Angeles County coastlines, breaking waves of 4 to 7 feet, with maximum sets of 8 feet, are expected, increasing to 5 to 8 feet through Tuesday, according to the NWS. The high surf then is likely to continue Tuesday night through Friday.

The conditions create "an increased risk for ocean drowning," warned an NWS statement on maritime conditions. "Rip currents can pull swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore."

Forecasters warned swimmers who get caught in a rip current to "relax and float. Don't swim against the current. If able, swim in a direction following the shoreline. If unable to escape, face the shore and call or wave for help."

Expect beach closures due to runoff for as many as 48-hours after the rain stops, according to the OC Healthcare Agency.

The rain is expected to again taper off Tuesday night and early Wednesday, but a third storm will move in late Wednesday and continue into Thursday. Forecasters say that storm could bring longer duration of rain that could again prompt flood watches.

"Given the amount of rain that will have fallen to that point, areas outside the burn areas may be at an increased risk for flooding, especially near smaller, flashier creeks and rivers, and other threats such as falling trees and rockslides," according to the NWS.

Photo, courtesy Patch Staffer Ashley Ludwig