Sunny and unseasonably warm weather in the Los Angeles area this weekend is expected to give way to cooler temperatures, strong winds and the possibility of showers later Sunday.
Forecasters say that a strong low pressure system from the Pacific Northwest will move through the area later in the day on Sunday, bringing very high winds, cold temperatures, dangerous seas and the chance of light showers and low-elevation snow.
The frontal system is expected to move in suddenly in the mid-to-late afternoon. Temperatures will tumble, with the most dramatic drops of 10 to 15 degrees forecast for coastal and valley areas, according to the National Weather Service. Temperatures in the 60s and lower 70s are forecast for those areas.
The storm could bring showers — there’s a 20% to 30% chance, forecasters say — and snow levels are expected to drop to 2,000 to 3,000 feet, which could complicate travel through mountain passes, including the Interstate 5 corridor.
But the strong winds are expected to pose the greatest hazard, with forecasters warning of possible downed trees and power lines and dangerous travel conditions.
“Rain is the least of the threat,” said Dave Bruno, a meteorologist with the weather service in Oxnard. “What we think is going to be the biggest effect of this storm system is the very strong northwest and north winds behind it, which will spread over most of Southern California.”
The Los Angeles, Ventura and Santa Barbara mountains could see gusts of 70-80 mph, with isolated gusts of up to 90 mph in the windiest areas, like the peaks above Interstate 5. Gusts of 60-70 mph are forecast for the valleys.
The peak of the event is expected to hit late Sunday evening through the overnight hours. The weather service expects to issue high-wind warnings and advisories for multiple locations.
“It’s not a run-of-the-mill wind event,” Bruno said. “It’ll be one of the stronger ones of the year.”
Travelers are advised to check road reports, especially if heading through the Grapevine or into the mountains.
The winds are also expected to whip up steep seas and high surf along the region’s beaches.
“It will be very unsafe for boaters anytime from tomorrow afternoon through Monday,” Bruno said. “The winds are going to make it quite dangerous throughout the coastal waters.”
Temperatures are expected to remain chilly into next week, with freezing conditions possible in some wind-sheltered locations Sunday night. That will be followed by a more widespread freeze on Monday night, when the winds die down but the cold air mass remains over the region, Bruno said.
During the day on Monday, however, temperatures are forecast in the 50s in many areas, possibly reaching the lower 60s in the warmest coastal regions.
“It doesn’t get much colder than this here,” Bruno said. “We’ll be seeing cool days and cool nights right through Thursday.”