Updated Tuesday, Jan. 5 – 1:25 pm
The second of four El Nino storms expected this week brought sometimes-intense rainfall to the Southland today, flooding intersections in the San Fernando Valley and sending muddy water cascading down at least one Glendora street near the Colby Fire burn area.
Rain began falling overnight and continued through the morning rush hour and into midday, making driving hazardous as water began pooling on streets.
By mid-morning, the Sepulveda Basin area began flooding, and a series of streets were blocked as water levels rose. One motorist driving a Mini Cooper found himself trapped when water rose up to the car’s doors. The man crawled out of the car and waded to safety without assistance from rescue crews.
The flooding resulted in multiple street closures near the basin. According to the Los Angeles Police Department, streets were blocked at Burbank Boulevard at the San Diego (405) Freeway, Burbank and Hayvenhurst Avenue, Burbank and Balboa Boulevard, Burbank and Victory, and Woodley and Victory.
Long Beach fire crews, meanwhile, rescued a person from rushing water in the Los Angeles River shortly after noon.
A flash flood warning was issued by the National Weather Service for the Glendora area, where the Colby Fire left hillsides bare and at risk of causing mudslides.
A flash flood watch will be in effect for most of Los Angeles County through Wednesday night. A similar warning is in effect in Silverado Canyon in Orange County, where a voluntary evacuation order was issued — but generally ignored by most residents.
An urban and small stream flood advisory for most of Los Angeles County will be in effect until 2:45 p.m.
"Residents in the vicinity of recent burn areas should be prepared for periods of heavy rain and a slight chance of thunderstorms this afternoon and again Wednesday morning through Wednesday night," according to the National Weather Service. "Peak rainfall rates may exceed one-half inch per hour during these periods.
"Rainfall rates this high have the potential to cause flash flooding and mud and debris flows," forecasters said. "Showers are expected to continue Thursday and possibly into early Friday…"
A "yellow" alert is in effect for residents near the Colby Fire burn area above Glendora. The alert directs residents to remove vehicles, trash bins and other obstructions from streets — both to ensure access for emergency vehicles and to prevent the items from being damaged or washed away in a mudslide.
The Colby Fire broke out Jan. 15, 2014, and scorched 1,992 acres.
As of this morning, no evacuation orders had been issued for the area bordering the Colby Fire site — which includes all properties north of Sierra Madre Boulevard between the western city boundaries of Azusa/Glendora to the eastern boundary of properties on the west side of the Little Dalton Wash.
Sierra Madre was closed early this afternoon between Yucca Ridge Road and Barranca Avenue due to flooding, mud and debris.
Glendora city officials reminded residents not to cross flowing water or mud, and protect themselves from debris flows on their property by going to the highest point in the house or the middle of a single-story residence.
Elsewhere in Los Angeles County, two mountain roads will be closed today due to anticipated hazardous driving conditions.
According to the Los Angeles County Department of Public Works, Lake Hughes Road is closed between Warm Springs and Newvale Drive. Glendora Ridge Road is closed between Glendora Mountain and Mount Baldy roads. The roads will reopen "once conditions permit," the county said.
In the San Gabriel Mountains, more heavy snow and gusty winds are expected today. And another storm — this week’s third — is expected to bring more snow and even stronger winds Wednesday, according to the NWS.
A winter storm warning, reflecting hazardous travel conditions, will be in force in the San Gabriels until 4 a.m. Thursday.
Forecasters said they expect between 1 and 2 feet of snow to accumulate above 6,000 feet, less at 4,500 feet.
The snow level will be between 6,000 and 7,000 today, then drop to between 4,500 and 5,000 feet Wednesday, NWS forecasters said. At the same time, south-to-west winds of between 15 and 30 mph, gusting to 45 mph, are expected today, rising to between 20 and 35 mph Wednesday and gusting to 55 mph.
The snow will make travel nearly impossible above 6,000 feet, NWS forecasters said, and at much lower elevations could affect Interstate 5 near The Grapevine.
Off the coast, hazardous conditions for mariners are expected much of the week, with forecasters warning of the possibility of thunderstorms over coastal waters today and Wednesday.
Any thunderstorm that forms would produce gale-force winds and "rough seas, dangerous cloud-to-water lightning, heavy rainfall with reduced visibility, small hail and isolated waterspouts," said an NWS statement.
Large long-period swells are appearing off the coast this week. The first will be evident through today, to be followed by a much larger swell lasting from Wednesday through Friday, it said. The larger swell will generate "hazardous breaking waves" at west-facing harbors in San Luis Obispo and Ventura counties.
The first of this week’s storms, which forecasters attribute to the El Nino effect, was Monday and proved to be weak. More storm activity is expected through the end of the week.