A red flag warning denoting a high risk of wildfire will be in effect for a fifth straight day Friday in the Antelope Valley and the San Gabriel Mountains, and forecasters warned that an elevated danger of fire will persist even after the warning expires and even in areas where no red flag warning has been in force.
The red flag warning for foothill areas of the Antelope Valley as well as the San Gabriels in Los Angeles and Ventura counties also applies to the Angeles National Forest in L.A. County and Ventura County’s Los Padres National Forest. It was issued Monday and scheduled to expire at 9 p.m. Thursday but was extended Thursday until 9 Friday.
The warning reflects low humidity, very dry vegetation, strong winds and high temperatures. But those conditions exist even beyond the red flag areas, according to NWS forecasters.
They said humidity levels, which have fallen to an uncommonly low 2 percent this week, would rise somewhat Friday but generally remain under 15 percent, and the vegetation in the drought-stricken region will stay very dry.
At the same time, onshore winds of between 15 and 25 miles per hour will sweep the San Gabriels this afternoon and evening and produce gusts of up to 40 mph, creating “critical fire weather conditions,” they said.
The same will occur in the Antelope Valley, where southwest winds of 15 to 30 mph are expected, gusting to 50 mph in the foothills, weakening tonight to between 8 and 15 mph, with 25-mph gusts, they said.
If there’s a spark, “conditions are favorable for extreme fire behavior and rapid spread of wildfire, which would threaten life and property,” warned an NWS statement.
The statement said that an “elevated fire-weather danger” would threaten interior areas of the Southland through Sunday “due to very warm and dry conditions, with breezy winds.”
It said the Santa Clarita Valley and Santa Monica Mountains in L.A. County and the Carrizo Plain in San Luis Obispo County will likely see 2 to 4 hours of red flag conditions through Friday — just under the duration required for the issuance of a red flag warning, “but still very concerning.”
“Some improvement is expected starting Monday, but elevated concerns will likely continue ever the interior areas,” it said.
Because of concerns about fire danger, Glendora Mountain Road and Glendora Ridge Road are closed today to motor vehicles. But cyclists and pedestrians are being allowed on the roadways, according to the Los Angeles County Sheriff’s Department.
Along the coast, a beach hazards statement — a notch below a high surf advisory in severity — will be in effect in Orange County through Sunday afternoon and in Los Angeles County through Sunday evening. Surf of 3 to 5 feet is expected, with some sets reaching 6 feet
“There is an increased risk for ocean drowning,” warned an NWS statement. “Rip currents can pull swimmers out to sea. Sneaker waves can suddenly wash people off of beaches or rocks and capsize small boats near shore” warned an NWS statement.
“Swim near a lifeguard. If caught in a rip current, remain calm. Don’t fight the current. Swim in a direction following the shoreline. When out of the current, swim back to shore.”
The NWS forecast a mix of partly cloudy and sunny skies in Los Angeles County Friday, along with highs of 74 degrees Fahrenheit at LAX; 75 in Avalon; 82 in Long Beach and downtown L.A.; 88 in San Gabriel; 89 on Mount Wilson; 90 in Burbank; 93 in Pasadena and Saugus; 95 in Woodland Hills; 98 in Palmdale; and 100 in Lancaster.
In Orange County, sunny skies are in the forecast, along with highs of 75 in San Clemente; 76 in Newport Beach; 78 in Laguna Beach; 83 in Anaheim and Irvine; 85 in Mission Viejo; 86 in Fullerton; and 90 in Yorba Linda.
Temperatures are expected to remain at roughly the same level through Thursday. A heat wave enveloped much of the region from last Saturday through Wednesday.
—Staff and wire reports