Hot and muggy conditions will linger across the Southland Saturday, but forecasters say relief is on the way, with temperatures expected to drop sharply by Sunday.
A heat advisory will remain in effect until 8 p.m. Saturday for coastal and valley areas of Los Angeles County, according to the National Weather Service.
The advisory follows an extreme heat warning that expired Friday evening across much of Los Angeles County.
In Orange County, an extreme heat warning will remain in effect until 8 p.m. Saturday for inland areas, while other areas will remain under a heat advisory until Saturday night.
Temperatures Saturday are expected to remain 5 to 10 degrees above normal on the coastal side of the mountains in Los Angeles County, although conditions will not be as hot as they were during the height of the heat wave.
The heat wave drove up temperatures throughout the week, with increased humidity adding to the discomfort and sparking occasional showers in some areas.
Forecasters said the upper-level high-pressure system centered over Arizona that brought the heat and tropical moisture into the region this week will move east toward Texas by Sunday. At the same time, a trough will move deeper into California.
The NWS said the movement “will shut off the tropical moisture feed by Sunday and replace it with a more typical dry southwest flow aloft.”
Temperatures will fall to 5 to 10 degrees below normal over the next 48 hours, forecasters said.
The threat of showers and thunderstorms will also diminish, although a shower or thunderstorm could develop Saturday in Los Angeles County mountain and desert areas before the threat ends, the weather agency said.
The marine layer is expected to return by Sunday or Monday.
Monday is expected to remain relatively quiet, but forecasters are monitoring the possibility of another influx of tropical moisture between Tuesday and Friday.
The most likely scenario calls for relatively normal temperatures and winds, with any tropical storms developing off the Baja California coast remaining to the south and west of Southern California, aside from potentially increasing surf.
Forecasters said there is a 10% to 20% chance that moisture from one of the storms could reach Southern California, bringing warmer and more humid conditions along with a chance of showers and thunderstorms.