Shedding Some Light on Why It’s So Gloomy

In case you hadn’t noticed, “June gloom” is back again, right on schedule, and Southern Californians are reacting as usual: with resignation and aplomb.

“We don’t like it,” said Frank Croteau, a 38-year resident of Huntington Beach, as he strolled down Main Street in shorts despite the chilly conditions. “It’s depressing.”

Added his wife, Betty: “We expect it. We tell people not to visit us in June.”

You can blame the “Catalina eddy” for some of the condition. And if things hold true to form, we’ll be having this cool, gray weather for most of the month.

Bill Hoffer, a National Weather Service meteorologist, said June gloom is the product of several interacting factors.

One of them is an immense blob of high pressure that tends to hang out off the West Coast. “It’s there all year around, but at this time of year it tends to intensify,” he said.

Winds circulate clockwise around high pressure, so there’s a flow of air down the coast that’s stronger than normal. At the same time, he said, the rotation of the Earth causes weather in the Northern Hemisphere to move from west to east.

The land mass of Central California tends to block this west-to-east movement as far south as Point Conception, where the coastline turns sharply to the east. With no land to block it any more, the rotational force takes over, creating an eddy that sweeps weather past Santa Catalina Island and into the L.A. Basin.

The water off the coast is still pretty cold. The cool, moist ocean air carried by the eddy flows onshore, where it hits the coastal mountains, is forced aloft and condenses into overcast. With increased sunshine because of the longer days of late spring, the air over the mountains and high deserts gets warmer, forming a cap, or temperature inversion, that holds the overcast in place, often all day. Result: the annual June gloom that’s depressing to residents and, at best, irritating to unsuspecting tourists.

“In the movies you always see California as sunny and warm,” said Carina Zenk, 17, a German exchange student, at an outdoor market in Huntington Beach. “We were planning to get tanned -- now we’re at the beach, but not in bikinis.”

By early July, according to Hoffer, the water off the coast will be getting warmer, and so will the onshore flow.

With less temperature differential between inland air and marine air, the cap becomes weaker and the overcast burns off, usually by midmorning, thus heralding the end of the gloom.

Surprisingly, not everyone is pleased by that prospect.

“I think this is perfect weather,” said Jenny Peta, 18, of Moreno Valley, strolling down Huntington Beach’s Main Street in a wet bikini on Friday. “The water was great.”

Mike Rapier, 39, arriving in the city with his wife and two children for the weekend from their home in Phoenix, couldn’t agree more. “It’s cold,” he said, “but we like it -- we came from 111 [degrees].”