SAN DIEGO -- Gusty, potentially damaging winds are expected to develop in parts of San Diego County this week, around the same time the second of two nearly back-to-back northwest swells churns up big waves along the coast.
A National Weather Service high wind watch for the mountains is scheduled from Thursday evening to Friday evening. A beach hazards statement will remain in effect from early Friday morning through Sunday morning.
Winds of 30 to 45 miles per hour are possible in the mountains overnight Thursday into Friday as a Pacific cold front moves through Southern California, along with gusts that may reach up to 70 mph in the windiest locations.
"An upper level trough of low pressure moving over the region late Thursday into Friday will bring periods of strong gusty west to northwest winds to portions of Southern California," according to the weather service. "The strongest winds are expected over the San Diego and Riverside County mountains, along the upper portion of the desert mountain slopes and through and below the San Gorgonio Pass."
Forecasters said the winds could be strong enough to damage trees, power lines and unsecured outdoor objects and may lead to hazardous driving conditions on stretches on Interstate 8 through the mountains. Visibility on some desert roadways may also be reduced to 5 miles or less due to blowing dust.
The second of two northwest swells to bring higher than average surf to San Diego County beaches is expected early Friday morning. The first hit Monday and prompted the closure of the Ocean Beach Pier on Tuesday.
Surf of 5 to 8 feet and occasional sets of 10 to 12 feet are forecast from Friday morning into Sunday, when the second swell will start to subside.
"This swell will bring high surf and strong rip currents through Sunday morning," according to the weather service. "Strong winds and high tides Friday and Saturday mornings will combine with the large swell to threaten coastal flooding and beach erosion."
Peak surf is expected along South County beaches Friday afternoon through Saturday morning. The winds are expected to peak Friday morning then gradually weaken late that afternoon, forecasters said.
The elevated surf combined with strong rip currents could lead to dangerous swimming conditions. Forecasters said waves may break over jetties and sea walls and minor beach erosion is possible with slight coastal flooding during high tides.
Also cooler weather, scattered showers and snow in areas above 5,000 feet are expected Thursday into Friday, according to the NWS.