The first in a pair of late-season storms doused the Southland today, setting the stage for a wet morning commute throughout the Greater Los Angeles area.
The rainfall, which developed after midnight, occurred over a wide area, including downtown L.A., Long Beach, parts of Orange County and the San Fernando Valley—with varying intensity, light in most places but heavy in others.
Although not continuous, the rain formed standing pools on area roadways, creating conditions ripe for hydroplaning, slipping and sliding, which could explain the few mostly single-vehicle crashes reported on Southland freeways after midnight and the crash of a big rig on the eastbound Foothill (210) Freeway in Pasadena. No injuries were immediately reported.
The FedEx truck was hauling two trailers when it crashed at Sierra Madre Villa Avenue around 4:30 a.m., said California Highway Patrol Officer Francisco Villalobos, adding that the second trailer overturned. Both trailers were empty, he said.
The cause of the crash was under investigation. Authorities closed the carpool lane, and the numbers one and two lanes while crews worked to clear the scene.
"People usually continue to drive at regular speeds when they should slow down," said Officer Anthony Martin of the California Highway Patrol's Los Angeles Traffic Management Center.
The rain, along with a slight chance of thunderstorms, was expected to persist on-and-off through mid-morning, according to National Weather Service forecasters, who said any thunderstorm could generate gusty winds and brief, heavy downpours packing small hail. Partly cloudy conditions will follow.
The storm is expected to generate between a third of an inch and an inch of rain in coastal and valley areas and between three-quarters of an inch and an inch-and-a-half along south- and southwest-facing mountains and foothills, forecasters said.
The predawn snow level was expected to range between 5,500 and 6,000 feet before dropping to between 4,500 and 5,000 feet later today, they said. Between four and eight inches of snow may accumulate above 6,000 feet, less at lower elevations.
"This storm will also bring gusty southwest winds to the mountains and deserts," according to an NWS advisory. Forecasters said they are expecting winds of between 20 and 30 miles per hour, gusting to 40 mph.
A winter weather advisory warning of challenging travel conditions because of snow and blowing snow will be in effect in the San Gabriel mountain in Los Angeles and Ventura counties until 5 p.m. today. During that time span, visibility could fall to zero, according to the NWS.
"The combination of snow and gusty winds in the local mountains could bring reduced visibilities due to blowing snow at times this week," according to an NWS advisory, which urged motorists to monitor conditions before venturing onto mountain roads.
In coastal and metropolitan areas of Los Angeles County, forecasters are expecting 15-mph southeast winds this morning, becoming southwest winds of between 10 and 20 mph this afternoon.
A second storm is expected this week. Forecasters said it appears it will generate precipitation Thursday night into Friday, more winds, and snow between 4,000 and 5,000 feet. But the precipitation is expected to end Friday night with showers, ushering in a return of dry weather.