Will we see 'May gray,' 'June gloom' this year?

Summer’s inching closer on the calendar in drought-parched Southe Califoia. Thank goodness we can count on “May gray” and “June gloom” to bathe us with refreshing, cool air before the real heat arrives.

Not so fast.

A possible victim of Califoia’s off-kilter weather of recent years, our aual cloudy relief from the relentless assault of triple-digit temperatures likely will be cut short this year, weather watchers say.

“It looks like a long, hot, dry spring through summer,” said Bill Patzert, a climate scientist at NASA’s Jet Propulsion Laboratory in Pasadena.

It’s something else you can blame on El Niño, Patzert added, because that weather patte is warming water all over the Pacific seascape. That’s expected to disrupt the conditions that invite all that pre-summer cloud cover to hang around for weeks.

“We’re definitely going to see less marine layer coverage in the next couple months,” said Tom Rolinski, a U.S. Forest Service meteorologist based in Riverside.

That has implications for everything from beach outings and park-trek barbecues — to the likelihood of wildfire season arriving early.

Lost tradition?

In a region marked by blurry distinctions between seasons, May gray-June gloom stands out. It is a fairly reliable weather phenomenon characterized by a deep marine layer that pushes well inland — on some days all the way to the San Beardino and San Jacinto mountains.

“It cools you off as it moves into the great Inland Empire cul-de-sac,” Patzert said.

Southe Califoians have a sort of love-hate relationship with the period of “low clouds and moing fog.” Inland residents mindful of the scorching days ahead cheer the temporary reprieve, while coastal residents eager for the sun to come out jeer unwanted chilly, gloomy days on the seaside sand.

“The marine layer helps us in a huge way,” said Richard Miich, a UC Riverside earth sciences professor and expert in fire ecology.

Besides holding temperatures down, Rolinski said the clouds hold moisture in the vegetation in the hills that will dry out later.

Rolinski said the marine layer generally affects areas 3,000 feet above sea level and lower. “Those fuels are going to be more moist than fuels that are farther inland and higher in elevation,” he said.

Some years, the clouds persist well into summer.

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“Those are years that we don’t have much fire activity in the grass and brush in the lower elevations,” Rolinski said.

But this isn’t expected to be one of those years.

Why less gloom?

What’s going to chase the clouds away? According to James Brotherton, a meteorologist for the National Weather Service in San Diego, it’s the water temperature offshore.

El Niño may not have been able to douse Southe Califoia with drought-erasing rains, but he might be able to undercut our pre-summer overcast.

At many locations, Brotherton said, the El Niño-warmed ocean surface is ruing 62 to 64 degrees. And the normal this time of year is 60 degrees.

That may not seem like a big increase, but it’s enough to make a potentially big difference in the weather, forecasters said.

Patzert said the strength of the marine layer is generated by the sharp contrast between the cool ocean and rapidly warming land.

Said Brotherton: “That clash of the air over the land is what causes that June gloom in a normal year.”

The contrast tends to be particularly strong in May and June, Patzert said, but will be less pronounced this year.

Brotherton said the ocean has been warm for many months.

“If those abnormally warm waters would continue, that would put a damper on the June gloom,” he said.

And those conditions just may strip away our gray. Which left at least one forecaster feeling gloomy.

“May gray — some people whine about it. But I always look forward it,” Patzert said. “Especially when it comes to my air-conditioning bill.”