Orange and Los Angeles counties are on target for back-to-back storms that will blow through the region starting late today, likely causing urban flooding and wind damage, according to the National Weather Service.

“It feels really nice outside now, but that’s deceiving because a big storm is coming,” said Alex Tardy, a meteorologist for the National Weather Service. “Orange County and Los Angeles County are right in the bull’s-eye.”

Early estimates are that the region will receive 2 to 4 inches of rain in coastal and valley areas and between 4 and 8 inches in the mountains and foothills, forecasters said.

The National Weather Service issued a flash flood watch for Southern California for Friday through Saturday afternoon. The Orange County Sheriff’s Department also cautioned in a tweet to stay out of flood channels.

By midday to late today, ominous clouds will begin rolling into the region, bringing 20 mph to 30 mph wind gusts from the south, with temperatures hitting the mid-60s.

“Then things turn nasty,” Tardy said.

Early Friday, at the peak of the morning commute, the heaviest rains are expected to pound Orange and Los Angeles counties and damaging winds could reach 60 mph along the coast throughout the day, Tardy said.

“This particular storm has a very strong jet stream, and we are going to take a direct hit in Southern California,” he said.

Orange and Los Angeles counties may be inundated with as much as 3 to 5 inches of rain, causing extreme runoff from already saturated soil. Driving may be a bit hazardous, with tree limbs falling and mudslides possible.

“It is getting dangerous,” Tardy said. “If this storm materializes, there could be urban-area flooding, particularly along the Santa Ana River and Los Angeles River.”

Some cities are already taking precautions by alerting residents to be prepared.

On its website, the city of Orange says it provides a maximum of 10 sandbags to Orange residents on a self-serve basis. They are available at the Water Yard, 189 S. Water St. You should bring your own shovel.

Costa Mesa provides up to 15 sandbags to its residents. It is also a self-serve process, available at City Hall, 77 Fair Drive.

Visit your city’s website for sandbag information where you live.

The storm could bring as much as 2 inches of rain to Riverside, 7 inches to the Santa Ana and San Gabriel mountains, and up to 5 inches in the San Bernardo mountain foothills, Tardy said. Ski resorts should receive at least a foot of snow.

Saturday will remain partly cloudy with a chance showers.

“The big thing Saturday will be cleaning up debris from Friday’s flooding,” Tardy said.

There will be a chance of light rain Sunday and Monday.

City News Service

contributed to this report.

Contact the writer: 714-796-7767 sschwebke@scng.com Twitter: @thechalkoutline