Heat Wave Sets Record High In LA; Flash Flood Warning Issued

LOS ANGELES COUNTY, CA — One of the worst heat waves in years continued to bake the Southland Saturday, with dangerously high temperatures expected to last well into next week, as firefighters battled two wildfires in Los Angeles County and a flash flood warning was issued in the high desert.

A heat advisory will be in force until 9 p.m. Sunday in L.A. County's coastal zone --- beach cities, metropolitan Los Angeles, Downtown L.A. and the Hollywood Hills.

Preliminary record high temperature set for Downtown LA, Woodland Hills, Camarillo, and the Oxnard NWS Office. Still plenty of time for temperatures to increase above these numbers. #CAwx #SoCal #LAheat pic.twitter.com/Dt423oP4kT
— NWS Los Angeles (@NWSLosAngeles) August 15, 2020

A more serious excessive heat warning will be in effect until 9 p.m. Monday in the San Fernando, Santa Clarita and San Gabriel valleys, and the San Gabriel and Santa Monica Mountains, in inland Orange County and the Santa Ana mountains below 5,000 feet; and until 9 p.m. Tuesday in the Antelope Valley.

Saturday's high reached 99 degrees in downtown Los Angeles -- a record for Aug. 15 -- with triple digit temperatures in much of the valley areas. It was 109 degrees in Lancaster and Palmdale. The previous record high for downtown L.A. on this date was 98 degrees, set in 1994.

"Extreme heat will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities," warned a National Weather Service statement.

Thunderstorms are detected on #GOES17 & lightning detection (blue) at 130pm. You can see a definite increase in activity across the San Gabriel Mountains & the Antelope Valley, including plume growth from the #LakeFire. Storms remain active in #SLOCounty also. #CAwx #TADD #LArain pic.twitter.com/yBxpJNgvwo
— NWS Los Angeles (@NWSLosAngeles) August 15, 2020

"Take extra precautions if you work or spend time outside," it urged. "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."

The NWS noted that the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments for people performing outdoor work.

"With the cloud mass clearing out on Friday, dangerously hot conditions are forecast to develop. Temperature well above normal for this time of year will occur, with several sites likely setting or tying record high temperatures for Friday," the NWS said. "Some sites in the hottest valley locations and across interior valleys could see temperature sky rocket close to 110 degrees."

A little after 1 p.m., the NWS warned the public to avoid the area around highways 138 and 18 near Llano in the Antelope Valley, where thunderstorms were likely to produce flash flooding.

A flash flood warning was issued for northeastern Los Angeles County until 6 p.m. Saturday.

The NWS also warned of elevated critical fire-weather through Monday, in part because of very dry vegetation, providing fuel for wildfires. Another factor is the fact that surface winds coming from the north will be weak, keeping the ground warm. But no red flag warnings have been issued.

The Lake Hughes Fire had burned 14,714 acres and was 12% contained Saturday afternoon, while the Ranch 2 Fire in Azusa had burned 1,400 acres and was 3% contained.

View of heavy rain producing thunderstorm near Llano in the Antelope Valley. Flash flooding likely or occurring. Avoid the area if possible, especially highways 138 and 18. #cawx #FlashFlood pic.twitter.com/ps5dDqcyPp
— NWS Los Angeles (@NWSLosAngeles) August 15, 2020

Smoke from those fires was causing unhealthy air quality in the San Gabriel Valley and the San Gabriel Mountains, the Santa Clarita Valley, the San Fernando Valley, and Pomona-Walnut Valley.

Cooling centers opened in the city and county of Los Angeles to give residents a place to escape the heat. The City of L.A's Department of Recreation and Parks and the county's Emergency Operations Center said cooling centers would be activated at specified facilities.

Due to COVID-19 social distancing requirements, capacity is limited and people are should call ahead to check space availability, according to the city Department of Recreation and Parks. Information on the county's cooling centers as well as heat-related illnesses and prevention is at publichealth.lacounty.gov.

A statewide Flex Alert was in effect Saturday afternoon, calling for residents to turn off their lights and help conserve electricity.

Power grid operators were predicting increased demand for electricity, according to the California Independent System Operator, which issued the alert to call for voluntary electricity conservation. Residents and businesses were being asked to reduce their energy consumption, especially between the hours of 3 and 10 p.m.

—City News Service