Los Angeles County faces highs of 90 to 105 degrees through Thursday, Sept. 10, just one day after Tropical Storm Marie dumped record-breaking rain across the region.
The National Weather Service (NWS) forecast widespread major heat risk for the LA Basin from Tuesday, Sept. 8, through Thursday. The agency issued a heat advisory for Wednesday and Thursday, the LA Times reported, and may escalate the warnings if conditions worsen.
Downtown Los Angeles and Long Beach could hit 96 to 98 degrees. Valley and inland communities could top 105.
Temperatures on Monday, Sept. 7, were already climbing into the upper 80s and 90s across inland LA County for the Labor Day holiday, according to the Eastsider. The NWS said temperatures would peak Wednesday, with highs largely between 90 and 105 degrees and widespread major heat risk.
Overnight lows will not help. The NWS forecast lows in the 70s, and even the upper 70s, Tuesday and Wednesday night. Temperatures are running 10 to 20 degrees above normal, the LA Times reported.
"If the clouds don't materialize, then Wednesday could be a real problem, and temperatures could really jump up," David Gomberg, lead meteorologist at the NWS in Los Angeles-Oxnard, told the LA Times.
Gomberg said lingering moisture from Marie, combined with the heat, would add to discomfort and create added heat stress. Isolated showers may continue through Tuesday even as temperatures rise, MyNewsLA reported.
Marie's weekend damage
The storm, downgraded from a hurricane to a tropical storm, stayed well offshore but pushed heavy rain and dangerous surf into LA County on Sunday, Sept. 6. Flooding hit parking lots at Seal Beach and Zuma Beach, and water flowed into homes and streets in Long Beach, according to the NWS.
Sunday's rainfall shattered daily records at multiple stations. Hollywood Burbank Airport recorded 1.3 inches, breaking the 1976 record of 0.82 inches. Downtown LA logged 0.70 inches, topping the 1965 record of 0.17 inches. LAX recorded 0.59 inches, and Long Beach Airport logged 0.68 inches, both also breaking decades-old records, NBC Los Angeles reported.
Waves at Zuma Beach broke as high as 12 feet over the weekend, the LA Times reported.
Beaches remain risky
A high surf advisory and coastal flood advisory remain in effect until 11 p.m. Tuesday, Sept. 8. South- and southwest-facing beaches can expect breaking waves of 6 to 10 feet with dangerous rip currents.
The Los Angeles County Department of Public Health issued a water-quality advisory for all LA County beaches until at least 2 p.m. Wednesday, Sept. 9. The department cautioned beachgoers to avoid water contact for at least 72 hours after rainfall. Officials had already urged inexperienced swimmers to stay out of the surf because of rip currents.
High tides are forecast to exceed 7 feet by Monday, Sept. 7, evening and 7.2 feet by Tuesday, Sept. 8, creating a moderate risk of coastal flooding.
How to stay safe
LA County residents can call 211 to find their nearest cooling center. City of Los Angeles residents can also call 311. More information is available at ready.lacounty.gov/heat.
The NWS said it is monitoring conditions and could upgrade the heat advisory if the week gets worse.
