Snow Prompts Portion of I-5 Closure

Running Springs (myFOXla.com) - A cold air mass blasted the Southland today on the heels of a storm, spawning early-morning frost and creating perilous driving conditions as the region braced for another round of wet weather later this week.

NWS forecasters said several areas of the Southland would be vulnerable to near- or sub-freezing temperatures overnight, including portions of the Antelope, Santa Clarita and San Fernando valleys, and the interior of the Santa Monica Mountain range. A frost advisory and a freeze watch were in effect in those areas.

The frost advisory -- which means affected areas can expect at least two hours of sub-freezing temperatures between 28 and 32 degrees, threatening crops, tender vegetation and animals -- was scheduled to expire at 8 a.m.

The freeze watch, which was scheduled to be in force through Wednesday morning, means there is a possibility of sub-freezing temperatures, falling below 28 degrees for at least two hours and threatening crops, vegetation and animals.

Similarly frigid conditions are expected again tonight, lasting into Wednesday.

Wind advisories and high wind warnings were allowed to expire early today, but NWS forecasters said some areas could still experience high winds.

Remaining in effect this morning and scheduled to expire at 9 a.m. was a winter storm warning in the mountains of Los Angeles County, except for the Santa Monica range.

Forecasters said snow showers would continue through mid-morning, especially across north-facing slopes, accompanied by winds in the 25-40-mile- per-hour range, gusting at times to 60 mph.

"The strongest winds will be focused through the Interstate 5 Corridor," an NWS advisory said. "The combination of strong winds and continued snowfall could create dangerous whiteout conditions at times along Interstate 5 near the Grapevine."

The advisory added that "there will be a high probability for dangerous city conditions across the mountains, including Interstate 5," as well as the likelihood of "dangerous wind chill readings near zero degrees."

Snow prompted the overnight closure of the 30-mile Grapevine section of the Golden State (5) Freeway starting at Parker Road at the Los Angeles County line, said California Highway Patrol Officer Patrick Kimball. The closure was expected to remain in effect until 6 a.m., he said.

The NWS says that motorists should "only travel in an emergency" when a winter storm warning has been declared and should keep an extra flashlight, food and water for use in an emergency.

The cold storm that hit the region Monday brought rain, fierce winds, power outages and blizzard conditions in high mountain passes. It also wrought chaos on freeways, causing nearly double the number of crashes experienced on Los Angeles County freeways on a dry day.

From 12:01 a.m. to 9 p.m. Monday, the California Highway Patrol counted 349 traffic collisions on roads under its jurisdiction, compared with 182 collisions a week ago on Nov. 30, a dry day, Kimball said.

Residents of nine homes in the Big Tujunga Canyon and Haines Canyon areas evacuated their residences for about four hours Monday due to fears of flooding or mudslides from the storm.

Los Angeles police went door-to-door notifying the affected residents around 1 p.m., but the city's Emergency Management Department lifted the evacuation order by 5 p.m.

A two-hour town hall meeting was held in Porter Ranch Monday night for residents living in burn areas created by the Station, Sesnon and Sayre fires to discuss flooding and mudslides.

Rainfall totals Monday included .99 of an inch at Los Angeles International Airport, .95 of an inch in downtown Los Angeles, 1.46 inches in Long Beach, 1.06 at the Chatsworth Reservoir and 1.08 inches in Claremont, according to NWS figures.

There were 10-14 inches of snow at Mountain High, 10 inches at Pine Mountain and eight inches at Wrightwood, the agency reported Monday.

The NWS said rain would return to the region Thursday and again over the weekend.

Temperatures were forecast to remain on the chilly side today, with highs of 41 on Mount Wilson; 44 in Palmdale and Lancaster; 47 in Newhall; 53 in Pasadena, San Gabriel, Burbank and Woodland Hills; 54 in Anaheim; 56 in Long Beach, Newport Beach, Avalon and at LAX; and 57 in downtown L.A.

Temperatures will climb three or four degrees Wednesday and remain above today's temperatures even when the rains return Thursday and at the weekend, according to an extended NWS forecast.