Extreme heat and high humidity made for a sweltering afternoon across the Southland Wednesday, with forecasters predicting similar conditions Thursday and warning of possibly thunderstorms.
According to the National Weather Service, the heat wave gripping the region was expected to peak on Wednesday and Thursday, with many areas expected to see temperatures as high as 108 degrees. Making the heat feel even worse were elevated humidity levels brought on by the remnants of Hurricane Marie, creating “oppressive” conditions.
Extreme heat warnings will be in effect until 8 p.m. Thursday for much of Los Angeles and Orange counties.
“For (Wednesday night), overnight low temperatures will offer little respite from the heat with lows in the 70s to lower 80s,” according to the National Weather Service. “On Thursday, the combination of some weakening of the upper level high pressure and more onshore pressure gradients will generate about 4-10 degrees of cooling west of the mountains with little change across interior sections. Humidity will still remain elevated on Thursday, resulting in continued significant heat issues.”
Forecasters noted that with the moisture in the air, afternoon showers and thunderstorms will remain a possibility, primarily in mountain areas.
“So with the plentiful sunshine so far today (Wednesday), expect shower and thunderstorm activity to increase through the afternoon hours,” according to the NWS. “Given the expected slow storm movement and plentiful moisture, there could be some flooding issues across the mountains this afternoon and early evening.”
A cooling trend is expected by Friday and Saturday, forecasters said.
The heat followed another round of rain and thunderstorms Tuesday as moisture from Marie moved through the region. Rain fell in areas including Burbank, Arcadia, Glendora, LAX and Manhattan Beach, while thunderstorms produced lightning across portions of Los Angeles County.
Los Angeles County lifeguards temporarily closed beaches from Cabrillo Beach to Zuma Beach Tuesday morning because of lightning.
The storm also produced high surf that damaged beachfront properties in Long Beach, Dana Point and Malibu.
Although the south swell from Marie was subsiding, the NWS said coastal impacts could continue Wednesday and Thursday around evening high tides.
“Expect continued beach erosion, flooded sandy beach areas, bike paths, and parking lots, as well as low-lying roads,” the NWS said.
A beach hazards statement will remain in effect through Thursday evening for portions of the Los Angeles County coast, with dangerous rip currents and some lingering southerly swell expected.
Forecasters said there is also a low chance of thunderstorms at beaches Wednesday.
The Los Angeles County Department of Public Health extended an ocean water quality rain advisory for all county beaches until at least noon Thursday because of rainfall. Beach users were advised to avoid all water contact, particularly near storm drains, creeks and rivers, where runoff can carry elevated levels of bacteria and other contaminants.
Officials had already urged inexperienced swimmers to stay out of the water because of dangerous rip currents.
Los Angeles County health officials also urged residents to stay hydrated, avoid outdoor activity during the hottest hours of the day and check on people at greater risk of heat-related illness, including older adults, young children, outdoor workers and people with chronic medical conditions.
“Heat causes more deaths in the U.S. annually than floods, storms, and lightning combined,” Los Angeles County Health Officer Dr. Muntu Davis said in a statement. “Those most likely to get ill during the heat include older adults, young children, outdoor workers, athletes, and individuals with chronic medical conditions.”
Residents without air conditioning were encouraged to use cooling centers, libraries, shopping malls and other air-conditioned locations. Information about cooling centers is available by calling 211 or at ready.lacounty.gov/heat/.