Several more days of dense fog, driven by a deep marine layer, are expected in Los Angeles, an unusual weather pattern for this time of year that is causing significant cooling in the region.
“It's more like a June pattern than a September pattern,” said Mike Wofford, a meteorologist with the National Weather Service in Oxnard. “And we don't expect much change over the next few days.”
A low pressure system swirling off the coast has created strong onshore flow in Southern and Central California, bringing clouds and cooler temperatures from the Pacific, Wofford said. He said this phenomenon is not unheard of in September, but is more typical in late spring and summer.
“A deeper layer of seawater is being generated, which even reaches the valleys,” he said. By mid-morning, most of the valleys will be clear, but some beaches in the area could remain foggy all day, he said.
The pattern brought some drizzle to parts of Los Angeles early Wednesday morning, Wofford said, but much more precipitation is not expected, although it is always possible.
“Whenever you have clouds like that, you can get scattered drizzle,” Wofford said. “It’s not going to get to the point where [the marine layer is] Super deep and generates [significant] rain.”
However, the clouds have lowered temperatures by about 10 degrees compared to earlier this week, Wofford said.
The colder weather comes after a heatwave hit the region in early September, bringing triple-digit temperatures and fueling several wildfires, before temporarily cooling over the past week.
“It's cooler than usual,” he said. Highs on the coast for the rest of the week are expected to be in the mid-60s and low-70s, while in the valleys they should remain in the mid-80s, well below average for this time of year.
And the forecast shows that trend won't change until early next week, Wofford said.
“Sometime around Tuesday… the onshore flow will be a little bit weaker and we will likely see some warming next week,” he said.
