Hot, humid weather continue to linger over Southern California with chance of thunderstorms

Extreme heat and muggy conditions were expected to continue across Southern California on Friday, along with a new chance of thunderstorms. 

After a sweltering Thursday that also saw the region hit with humidity levels higher than some southern states like Louisiana and Florida, residents in Los Angeles, Orange, Riverside and San Bernardino counties could expect much of the same until Sunday, forecasters said. 

Extreme heat warnings already in place were extended through Friday at 8 p.m. in LA and Orange counties, according to the National Weather Service. Forecasters said that the cloud cover that lingered over parts of Southern California on Thursday led to what felt like cooler temperatures, but the humidity made conditions feel much more uncomfortable. 

"Despite the numeric cool down, most will agree that it still feels hot as dewpoints are around 70 degrees for much of our region, which is similar to Florida right now," the NWS said in their Thursday forecast discussion. 

Students and faculty at Cal State Los Angeles were forced into "modified operations" on Friday due to issues with the campus's cooling system. School officials asked professors to switch to remote learning if possible to prevent health and safety concerns while they continued working to address the issue.

The moisture was expected to leave the area on Friday night, which will lead to a cooler and drier weekend more typical for Southern Californians. Substantial cooling is predicted for Sunday, when temperatures are expected to drop below the average along with the return of the marine layer cloud cover on the coast. 

Friday conditions were expected to be hotter than Thursday due to a lessening in cloud cover. That moisture, paired with the remnants of Tropical Storm Iselle, could increase the chance of showers and thunderstorms, the NWS said. The areas most likely to see rain and thunderstorms are in northern Los Angeles County. 

"The main threat will continue to be cloud-to-ground lightning and erratic winds, which pose a significant risk for fire starts and growth," the NWS said, noting that red flag warnings were in effect until 3 p.m. on Friday in the San Gabriel Mountains and along the I-5 and SR-14 freeway corridors. 

Forecasters warned that the triple-digit heat, gusty wind and lower humidity in inland parts of Southern California could produce elevated to critical fire weather conditions.