Although rain fell seemingly throughout the night in some parts of the basin, as of early Monday morning the National Weather Service indicated that most of Los Angeles County had received less than an inch of precipitation. But the isolated showers expected into Monday evening might change that.
The Hansen Dam area received just less than an inch as of 8 a.m., as did Culver City, La Verne, Alhambra and mountain areas including the San Gabriel dam.
Portions of Santa Barbara and San Luis Obispo counties were hit harder, with some areas receiving more than an inch-and-a-half of rain. For those looking for a trip to the mountains, Mountain High received up to 10 inches of snow, while Pine Mountain had about 6 inches. Lower-elevation Frazier Park received about 4 inches.
There were reports of some flooding overnight, including on the 10 Freeway in El Monte. Forecasters also warned of a continued possible threat of debris slides in recent burn areas, saying some areas could get brief downpours that could trigger slides, particularly later in the day Monday.
"The threat for significant and damaging debris flows is small, but not zero,'' according to the NWS.
In Monrovia, residents on Sunday stacked up sandbags to protect their homes.
The Bobcat Fire burned more than 100,000 acres in the San Gabriel Mountains and the Angeles National Forest in September. Monday's rain could trigger flooding and debris flows in nearby hillside communities.
RELATED: Monrovia residents fear storm could trigger mud, debris flows in Bobcat Fire burn area
Los Angeles County lifeguards, meanwhile, reported the "rare sight'' of slush and hail at some beaches, warning that storm water being carried to the coast can lead to significant beach erosion, while also carrying substantial pollutants to the ocean. That flow of pollutants prompted the Los Angeles County Department of Public Health to issue a Beach Water Use Advisory, urging people to avoid entering the ocean for swimming, surfing or other activities near discharging storm drains or creeks. The advisory will remain in effect until at least 7 a.m. Thursday.
According to the NWS, the storm system was moving southeast out of San Luis Obispo County.
"This will maintain showery conditions across the area through this afternoon at least,'' according to the NWS. "No lightning strikes have been detected in several hours but with the upper low coming through today providing some additional energy and cold air, there's a reasonable chance for at least a few more thunderstorms, especially over or near the coastal waters.''
Forecasters said a risk of snow will linger throughout the day along the Grapevine in northern Los Angeles County.
Temperatures will remain relatively chilly, with most areas unlikely to reach the 60s.
Los Angeles County issued a cold weather alert through Wednesday for Lancaster, through Tuesday for Mount Wilson, and for Tuesday and Wednesday in the Santa Clarita Valley. County officials noted that those areas could see near-freezing or below-freezing temperatures at night.
The Los Angeles County Department of Public Health urging people in the area to:
-- wear layers of warm clothing if they plan to be outdoors;
-- wear a hat, scarf, gloves and socks to protect their head, hands
-- check in frequently with family, friends and neighbors who have
limited mobility or access to heat; and
-- bring pets inside and do not let them stay outside overnight.
The storm system should mostly move out of the region by Tuesday, and forecaster say gusty winds are expected Tuesday through Friday, bringing gusts of up to 50 mph to particularly wind-prone areas. Humidity levels will also drop in some mountain and lower-elevation areas. But thanks to the rain, the region will likely avoid any red-flag warnings of severe fire danger, but "pockets of two to four hours of critical weather conditions are possible.''
City News Service contributed to this report.