After an unseasonably cool June weekend across much of Southern California, high summer temperatures are expected to return to the region along with the chance of some of the first monsoonal activity of the year throughout the deserts and mountains, meteorologists predicted Sunday.
The heat increase will become apparent as soon as Monday, June 20, as many inland areas will see temperatures rise 10 to 15 degrees higher than they were Sunday, said Brian Adams, meteorologist with the National Weather Service.
In Los Angeles County, valley areas will be some of the hardest-hit regions Monday as Santa Ana winds are projected to warm and dry the air, said David Gomberg, meteorologist with the NWS. Both the San Gabriel and San Fernando valleys will have high temperatures in the 90-degree and higher range, with areas like Woodland Hills expected to reach triple digits, Gomberg said.
“We’re entering into some of our hottest weather (of the year so far) right now,” Gomberg said.
In the Inland Empire, high temperatures are expected to be in the 90s as well, with a few areas possibly topping out around 100 degrees, Adams said.
Daily high temperature records aren’t anticipated to be broken this week, both meteorologists said.
Here are the high temperature graphics for today, Monday and Tuesday, and the precipitation chances Wednesday. No, that’s not a typo! An early season monsoon surge may generate a shower or thunderstorm Wednesday afternoon. #cawx pic.twitter.com/JgsSgLS9kj
— NWS San Diego (@NWSSanDiego) June 19, 2022
The ramp-up in temperatures will be the result of a high-pressure system positioned over the Pacific Ocean near the West Coast, Adams said. In addition to this system, another high-pressure system near the Gulf of Mexico is expected to begin driving some of the first monsoonal moisture of the year into Southern California, bringing a potential for rain and thunderstorms beginning Wednesday afternoon, June 22.
“It’s a bit early to tell of the storm as far as impact goes,” Adams said. “(Precipitation) could be relatively sparse, but it’s tough to say now.”
Monsoonal weather patterns are typical for this time of the year as the traditional monsoon season has kicked off across much of the desert southwest, the meteorologists said. The eastern San Gabriel Mountains and the San Bernardino County mountains are the usual suspects for monsoon-like weather to develop due to high elevations, Gomberg said. Monsoonal weather also could affect parts of western Riverside County, the NWS said.
Monsoon-like thunderstorms can lead to cloud-to-ground lightning strikes, flash flooding and mudslides in areas recently impacted by wildfires.
But with varying anticipated precipitation totals, the storms this week are not expected to have much a major impact on the drought gripping most of the state and the desert Southwest, Gomberg said.
“We usually see spotty storms and more in the mountains and deserts,” Gomberg said. “We’re not going to get a whole lot of moisture along the coast or valleys.”
But while Tuesday, June 21, marks the first day of summer, much of coastal Los Angeles and Orange counties is expected to remain cool, Gomberg said. The warmest marks expected along the coast will be in Long Beach, possibly reaching highs in the mid-80s, he said.
The hot inland weather is expected to persist through the week and possibly even through the weekend, both meteorologists said. In fact, valley areas of Los Angeles County may experience widespread high temperatures in the triple-digit range on Friday and Saturday, Gomberg said.
A similarly warm weather pattern is expected for next week as well, with more chances of monsoons early in the week, Adams said.