Hurricane Marie is expected to stay hundreds of miles offshore of Southern California, but forecasters say the storm will still have a noticeable impact on Labor Day weekend plans across parts of the region, bringing periods of rain, the possibility of thunderstorms, dangerous surf, and an elevated risk of coastal flooding.
According to the National Weather Service (NWS), Marie was located about 700 miles south of Point Conception on Saturday evening and is forecast to move west-northwest while gradually weakening.
Even so, tropical moisture associated with the system is already affecting Southern California.
“Tropical Cyclone Marie, which will remain well offshore of SoCal, will bring impacts to the region through at least early next week,” the NWS said.
Rain and Thunderstorm Risk
The most immediate impact for Labor Day weekend is expected to be rainfall across Los Angeles County beginning early Sunday morning and lasting into Sunday evening.
Forecasters say most of the rain will be light to moderate, with Los Angeles County seeing the greatest precipitation totals.
Most locations are expected to receive around a quarter-inch of rain or less, though foothill communities in the San Gabriel Valley could see around half an inch, while isolated spots in the eastern San Gabriel Mountains may pick up as much as an inch.
The NWS also noted up to a 15 percent chance of thunderstorms across Los Angeles County on Sunday. Any storms that develop could produce locally heavier downpours.
“There is a chance of heavier rain occurring near any thunderstorms that form,” forecasters said, adding that tropical moisture from Marie could combine with daytime heating to produce scattered showers and isolated thunderstorms, with some areas receiving brief periods of heavier rain.
While widespread flooding is not anticipated, officials warned that roads could become slick after months of dry conditions. The NWS estimates only about a 5 percent chance that rainfall rates will become high enough to cause minor urban flooding in Los Angeles County.
Rain chances may continue beyond the holiday weekend. The NWS said remnant moisture from Marie could support additional showers and isolated thunderstorms Monday and Tuesday, with another round of activity possible later next week.
Dangerous Beach Conditions
For many Southern Californians marking the unofficial end of summer at the beach, the most significant impacts may come from the ocean rather than the sky.
The NWS warned that “significant coastal impacts are expected across Southern California beaches this Labor Day weekend” as a large southeast-to-south swell generated by Hurricane Marie moves into regional waters.
Wave heights on south-facing beaches in Los Angeles and Ventura counties are expected to reach 5 to 8 feet, with some sets potentially approaching 10 feet through Monday.
High Surf Advisories remain in effect for those areas.
The swell is also creating dangerous rip currents and strong surges in harbors.
Marine forecasters said a large southeast-to-south swell will continue affecting coastal waters through the holiday period, increasing hazards for swimmers, surfers, and boaters.
Coastal Flooding Concerns
Another concern is the potential for minor coastal flooding during periods of high tide.
Forecasters said tides are expected to exceed 7 feet by Monday, and when combined with incoming swell from Marie, could produce flooding along vulnerable south-facing shorelines.
Areas identified as particularly vulnerable include Avalon on Catalina Island, Long Beach’s Alamitos Peninsula, and parts of the coast stretching from Oxnard to Malibu, including Point Mugu.
Warm and Humid Holiday Weekend
Despite the clouds and rain chances, temperatures are expected to remain close to seasonal norms. The tropical air mass associated with Marie will create more humid conditions than Southern California residents typically experience.
The NWS said overnight temperatures may remain unusually warm, staying in the 70s along some coastal and valley communities. Humidity is expected to persist into next week, with moderate heat risk possible as temperatures gradually warm Monday through Wednesday and even Thursday.
For those celebrating Labor Day outdoors, the message from meteorologists is clear: keep an eye on local forecasts, be alert for rapidly changing conditions near the coast, and use extra caution at beaches where dangerous surf and rip currents may pose the greatest threat.
Contact Newsweek editors on this story: Matthew Cannon and Cristina Diciu.