Laguna Niguel's Heatwave Lingers Into Weekend; Fire Risk Critical

LAGUNA NIGUEL, CA — Just when it seemed like this record-breaking heat wave would break, forecasters warned that the high-pressure system responsible for turning up the heat will linger through the weekend.

Southern Californians can expect slight cooling Saturday and Sunday, but inland areas, mountains and valleys will remain unseasonably hot until next week, forecasters warned.

And with the hot weather will come windy conditions, creating an increased risk of brush fires, according to the National Weather Service. Southwest winds are also expected to increase through Sunday, combining with the heat and low humidity to create "elevated to brief critical fire weather conditions, most prevalent over the weekend."

"High pressure aloft will continue to dominate the weather pattern across southwest California through Saturday," according to the NWS. "Hot conditions will continue during this time across interior areas. Areas of low clouds will be confined to the coast. A cooling trend is expected over the weekend and into early next week with more extensive night through morning low clouds and fog."

Although the high-pressure system that has been turning up the heat peaked on Wednesday, it "will remain relatively strong through the weekend, with hot and dry conditions across our interior valleys, mountains and deserts, including the warmer coastal valleys," according to the weather service.

"Highs between 98 and 108 will be common Friday, lowering to 92 to 102 by Sunday. Minimum humidities between 8 and 15 percent will be common through Sunday," the NWS said.

According to the National Weather Service, a record high temperature of 111 degrees was set in Lancaster on Thursday, breaking the old record of 105 set in 1961 and 2017. Palmdale Airport also recorded a record daily high of 109, breaking the old record of 107 set in 1961.

Some cooler temperatures were in the Friday forecast, but there will be hot spots as well, according to the weather service.

Meanwhile, the California Independent System Operator, which manages the state's power grid, issued a Flex Alert for 5 to 10 p.m. Thursday, calling on residents to voluntarily reduce their power use to ease strain on the system and prevent possible power outages. Residents were urged to avoid using major appliances during the alert, turn off unnecessary lights and set thermostats at 78 degrees or higher.

The alert will be in effect again from 6 to 9 p.m. Friday.

An excessive heat warning will be in place in the Los Angeles County mountains, excluding the Santa Monica range, until 9 p.m. Saturday. The Antelope Valley was under the same warning, and forecasters extended it until 9 p.m. Sunday, predicting continued oppressive heat reaching as high as 111 degrees.

A less-severe heat advisory was in effect for the Santa Clarita Valley until 9 p.m. Saturday.

The San Fernando and San Gabriel valleys, along with the Santa Monica Mountains Recreational Area, had been under a heat advisory, but that was allowed to expire on Thursday.

In Orange County Inland areas, a heat advisory was canceled early Friday morning. Highs there Friday will be mostly in the mid 80s, according to the weather service.

Forecasters urged residents to take precautions to avoid being overcome by the heat, particularly in areas under excessive heat warnings.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the NWS advised. "Young children and pets should never be left unattended in vehicles under any circumstances.

"Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible."

Also due to the heat wave, the South Coast Air Quality Management District issued an ozone advisory through Saturday, predicting increased likelihood of poor air quality in many areas. Levels of ground-level ozone -- the predominant summertime pollutant -- are likely to reach unhealthy or higher air quality index levels throughout most of the Southland.

The Los Angeles County health officer issued a heat alert warning of high temperatures in the eastern San Gabriel Valley through Friday, the Santa Clarita Valley through Saturday and the Antelope Valley through Sunday.

The alert reminds everyone in the affected regions to take precautions to avoid heat-related illness, especially older adults, young children, outdoor workers, athletes, and people with chronic medical conditions.

Public Health officials issued the following recommendations to stay safe during high temperature days:

-- Drink plenty of water throughout the day;

-- Plan your day to avoid going out during the hottest hours, and wear sunscreen;

-- Wear lightweight, light-colored clothes, and wear a hat or use an umbrella;

-- Never leave children or pets in cars and call 911 if you see a child or pet in a car alone;

-- Beware of heat-related illness, like heat stroke and call 911 if you or someone you know is experiencing high body temperature, vomiting, and pale and clammy skin;

-- Check on those at risk, such as those who are sick, older adults, pregnant women, and children, and those who live alone; and

-- If you are wearing a mask, avoid strenuous workouts wearing face coverings or masks not intended for athletic purposes.

"While it is very important that everyone take special care of themselves, it is equally important that we reach out and check on others, in particular those who are especially vulnerable to the harmful effects of high temperatures, including children, the elderly, and their pets," said Los Angeles County Health Officer Muntu Davis.

"High temperatures are not just an inconvenience, they can be dangerous and even deadly."

County and city partners operate cooling centers during times of high heat. Residents who do not have access to air conditioning are encouraged to take advantage of free cooling centers. To find a location, visit https://ready.lacounty.gov/hea... or call 211.

Los Angeles County residents and business owners, including people with disabilities and others with access and functional needs can call 2-1-1 for emergency preparedness information and other referral services.

City News Service and Patch Staffer Paige Austin contributed to this report.