Rain Cancels Holiday Events, Causes Slides : Weather: San Juan Capistrano, with 1.5 inches, received the most rainfall in Orange County. The record Memorial Day downpour thwarted the plans of many.

An unexpected, wintry rainstorm swept through Southern California on Monday, dumping record rainfall that unleashed mudslides and caught Memorial Day celebrants unprepared and underdressed.

The morning storm dropped more than an inch of rain in some places, washing out camping, picnicking and sun bathing and forcing organizers of a variety of Memorial Day observances to alter their programs or cancel them altogether.

“We didn’t see it coming down so far with such intensity,” said Steve Burback, a spokesman for WeatherData Inc., which provides weather information for The Times.

Burback said the storm originated in the Gulf of Alaska and moved into Southern California at about 3:30 a.m., bringing with it below-normal temperatures and record amounts of rainfall.

In Orange County, San Juan Capistrano received the most rainfall, collecting more than 1.5 inches, while Santiago and Modjeska peaks received 1.4 inches, Burback said.

The high temperature in Santa Ana was 67--about 10 degrees cooler than normal for this time of year, Burback said.

National Weather Service spokesman Jerry Steiger said that total rainfall in Santa Ana measured 0.52 inches and Anaheim experienced a third of an inch of rainfall.

Burback said a general clearing with scattered high clouds began Monday afternoon and was expected to continue through today.

In downtown Los Angeles, 1.17 inches of rain fell--a breakaway record, since the best any previous Memorial Day could muster was 0.12 of an inch. “It’s acting more like wintertime,” Burback said. Snow that measured as much as four inches at Big Bear melted when it hit the ground elsewhere in the mountains, he added.

None of this put much of a dent in the drought: For example, while the 1.17 inches brought Los Angeles’ monthly total to 1.20 inches, this year’s rainfall so far amounts to 7.38 inches, not quite half of the normal 14.82 inches.

But the quenching rain at the same time dampened Memorial observances.

For 25 consecutive years, Forest Lawn Memorial Park in Cypress has remembered the thousands of soldiers, sailors, airmen and Marines who died in war. But persistent rainfall Monday morning caused mortuary officials to cancel the 11 a.m. service, manager Darren Drabing said.

“We were all very disappointed that we had to break it off,” Drabing said.

In Fullerton, however, the Loma Vista Memorial Park observance was held in spite of a steady drizzle. Cemetery spokeswoman Sharon Adams said the ceremony lacked only the 500 large American flags that were to line the main entrance to the memorial park.

More than 500 people huddled under umbrellas and white canopies to listen to Maj. Gen. Norris Einerston, chief chaplain of the Army, deliver a somber address, Adams said. Small flags and crosses were then placed on the graves of about 3,000 veterans buried in Loma Vista.

Throughout the county, beaches, campgrounds and parks were mostly empty as the thick cloud cover and occasional downpour forced a mass exodus to warmer and drier activities.

The pre-summer holiday, normally marked by sun worshiping and other outdoor activities, was the bleakest in memory.

“I got only one color for you out here. That’s gray,” Newport Beach lifeguard Jim Turner said of the dismal day that looked more like mid-January than the start of beach season.

By mid-morning, the only sign of life in the normally crowded beach resort was on the Newport Pier, where disappointed beach-goers wrapped in sweat shirts, jackets and blankets forlornly watched the surf.

By contrast, Turner said, more than 90,000 people flocked to Newport Beach on Sunday. But with winds reaching 25 m.p.h. on Monday, Turner said, air temperatures dipped to about 48 degrees, and not a soul could be spotted on the stretches of sand.

“Even the die-hards are gone,” Turner said.

Camper Dick Cliver, however, counted himself as a die-hard, deciding to stick out his San Clemente beach vacation despite chilling temperatures, soggy clothes and a damp tent.

“We found out that the tent leaked and so does the camper,” said Cliver, sitting in an eight-foot camper atop a pickup truck at San Clemente State Beach. Nearby, dozens of footprints in the soft mud led to a huge nylon tent filled with the soaked belongings of family and friends.

“But it’s not driving us out,” said Cliver, a Buena Park resident. “We’ll just sit in here and watch it rain if we have to.”

Carl and Lindy Spencer and their two children, who drove all night in the rain from Las Vegas, spent the first part of a week’s vacation at Doheny coping with flooded campgrounds and the downpour.

They managed to erect two nylon tents and tied a clothesline from their car to a nearby tree to dry out drenched clothes and towels.

Interstate 5 was hit hard early in the morning, with flooding causing closures along the freeway at Junipero Serra Road in San Juan Capistrano and Red Hill Avenue in Tustin, the California Highway Patrol said.

The CHP was also kept busy rushing to the scenes of more than a dozen traffic accidents that slowed highways to a crawl in many areas. They attributed the majority of accidents to slick roads.

“Generally on the first day (of rain), it’s the craziest,” said CHP Officer Bryan Duquesnel. “They are just cranking on down the road and don’t pay attention (to water hazards).”

A stretch of Dana Point Harbor Road leading to the Dana Point Marine Institute and a residential road near the intersection of Street of the Golden Lantern and Camino del Avion in Laguna Niguel were closed temporarily due to mudslides.

“The water and the mud were up to my knees,” said County Harbors Beaches and Parks worker Brian Young as he worked to clear Dana Point Harbor Road, which leads to the Dana Point Marine Institute. “It was a pretty big slide.

As the rain subsided later in the afternoon, thousands of Orange County residents had changed their outdoor plans and opted to flock to area malls instead.

“It’s been busy like mad,” said Mona Salameh, an employee at the May Co. department store in South Coast Plaza. “I went out into the mall and it’s the busiest I’ve seen it since Christmas.”

Typically, Memorial Day draws a fair amount of shoppers because many stores advertise sale prices and stay open longer hours, but today was exceptionally busy because of inclement weather, Salameh said.

Times staff writer Patt Morrison contributed to this report from Los Angeles.