Hourly Rain Forecast: Storm Arrives In San Juan Capistrano

SAN JUAN CAPISTRANO, CA — A cold storm out of the Gulf of Alaska slowly advanced on the Southland Thursday— much slower than originally anticipated —with precipitation now expected to begin in Los Angeles County well after sundown.

"Rain is coming, but a little later than expected," according to a National Weather Service advisory issued mid-morning.

Forecasters said the rain is "expected to arrive this afternoon across the Central Coast and probably not until 8 or 9 p.m. in L.A. County."

A winter weather advisory that was originally expected to take effect at 1 p.m. in the Los Angeles County Mountains, excluding the Santa Monica range, was pushed back until 7 p.m., continuing until 1 a.m. Friday.

In San Juan Capistrano, your hourly forecast shows rain arriving at 10 p.m. until 5 a.m.

According to the WeatherChannel.com here are the chances of rain in your area:

• 9 p.m.: 45-percent chance of rain
• 10 p.m.: 65-percent chance of rain
• 11 p.m.: 70-percent chance of rain
• 12 p.m.: 65-percent chance of rain
• 1 a.m.: 60-percent chance of rain
• 2 a.m.: 55-percent chance of rain
• 3 a.m.: 40-percent chance of rain
• 4 a.m.: 15-percent chance of rain
• 5 a.m.: 5-percent chance of rain

Forecasters said the affected mountain areas will likely see snow as low as 3,500 feet by late Thursday night, with accumulations ranging from 2 inches at lower elevations to 6 inches above 5,500 feet.

"No significant impacts" are expected from the storm, according to the NWS, "other than snow issues in the mountains and possibly the Grapevine (Thursday night) and the usual ponding of water in urban areas."

Mountain areas can expect south-to-southwest winds of 25 to 35 mph, with occasional gusts up to 50 mph, forecasters said. Road closures may be required on Interstate 5 through the Grapevine and Ventura County's Highway 33, according to the NWS.

The Antelope Valley will also be windy, with the weather service forecasting winds 20 to 35 mph, with gusts of up to 50 mph. The strongest winds will be in the foothills.

No mud slides or debris flows are expected over slopes previously denuded by wildfires — in L.A., Orange and Riverside counties —because the rainfall at no time is expected to exceed a half-inch per hour, said meteorologist Curt Kaplan at the National Weather Service's Oxnard station.

In Orange County, the "weak" storm's main band is expected to arrive at about 11 p.m. and linger until about 4 a.m. Friday, producing "light showers" amid southwest winds of between 15 and 18 mph, said meteorologist Miguel Miller at the NWS station in San Diego, where Orange County conditions are forecast and monitored. The storm will clear out by sunrise, he said.

Forecasters originally anticipated between a quarter-inch and three- quarters of an inch of rain along the L.A. County coast and in the county's valleys, but given the delay in the storm's arrival, those areas likely will receive "at or below a half-inch." The storm front will likely be out of Los Angeles County entirely by 3 a.m.

Dry conditions are expected to return Friday, although cloudy conditions could persist through Saturday. Temperatures should get warmer through the weekend, thanks to weak northeasterly winds. There is chance of some light showers returning early next week.