The seasonal occurrence of damp, cool and cloudy weather in Southern California, also known as ‘June gloom,’ has arrived right on schedule, and according to AccuWeather meteorologists, it will stick around for a while.
The clammy weather comes on the heels of a cool, wet winter for the Golden State, which helped end a long-term drought and improve prospects for the state’s beleaguered water supply. For those longing for a return to dry, sunny and warmer days, the phenomenon could persist longer than usual, as it is expected to last deep into June.
“Much of California is locked in a pattern that is typical for this time of year, where constant storms are moving into the state, allowing a deep marine layer to form,” said AccuWeather Meteorologist Haley Taylor. “A marine layer is essentially cool, moist air that sits near the surface below warmer, drier air.”
The marine layer brought inland from an onshore flow is well known to locals and leads to the formation of low clouds, fog and even drizzle that can persist all day in some areas.
“When winds are blowing onto the shore, that cool, moist air gets pushed inland, and low clouds and fog can form,” added Taylor. “Air wants to flow from high to low pressure, so when there is a storm over California, the pressure difference over California and over the ocean leads to this onshore flow.”
While this onshore flow is most common in the month of June, it can also occur year-round, especially in surrounding months from spring into summer. Some other colloquial names for months when this onshore flow frequently occurs include “May Gray,” “No-Sky July,” and “Fogust,” according to SFGATE.
While the low clouds from the onshore flow can last all day at the coast, they are typically scoured out later in the day in inland areas.
“During the late morning and afternoon on most days, sunshine above the clouds helps to drag drier air higher into the atmosphere down to the surface, thus scouring out the clouds,” said AccuWeather Senior Meteorologist Alex Sosnowski.
However, the unusually cool, moist nature of this year’s June gloom has led to more cool, cloudy days deeper inland, including across parts of the San Francisco Bay Area, the Los Angeles basin and around San Diego. This is largely due to the fact that the persistent stormy pattern that was seen over the winter never really ceased in the spring months.
In Downtown Los Angeles, temperatures have been running 2 degrees Fahrenheit below historical averages since the beginning of May due to the prevalence of the marine layer. A similar deficit has been recorded in San Diego, where the temperature is 2.1 degrees below average through June 6.
In the short term, more gloomy weather is ahead, according to AccuWeather forecasters.
“A storm is currently in the process of moving out of California through Thursday, allowing high pressure to settle in,” said Taylor. “With this pressure difference, the marine layer doesn’t look to be as deep as previous days, but it’ll still be around and widespread.”
A new storm moving into the region this weekend, and lasting into early next week, can deepen that marine layer again into the middle of June.
“We are likely looking at several more days of a thick, slow-to-clear cloud cover and even some drizzle closer to the coast, beginning this weekend” added Taylor.
The persistent cloudier, cooler weather is also impacting honeybees in Southern California.
“The weather this year has been really, really tough on the bees, because it’s been cold and raining almost nonstop, and that’s unusual for Southern California,” Jay Weiss, a backyard beekeeper from Altadena, said in an interview with AFP.
The honeybees won’t typically emerge and start to produce honey until the weather turns sunnier, drier and warmer for several consecutive days.
“I’ve been beekeeping for almost 20 years now, and we really haven’t had this type of a condition, where it was continuously raining and cold for February and March,” added Weiss. “However, when they start making honey, it’s unbelievable how fast things happen.”
The prospects of the June gloom ending anytime soon are dim. According to AccuWeather’s team of long-range forecasters, led by Senior Meteorologist Paul Pastelok, the persistent trough of low pressure near and just offshore of the West Coast, which has recently led to the stormy weather and stout marine layer, will likely persist for the rest of the month.
“I can even see how some of this gloomy weather hangs on into July, largely due to the cooler-than-average water temperatures offshore,” said Pastelok.
Produced in association with AccuWeather