Valley-Area Swelter Breaks Records : Weather: Van Nuys endures 111 degrees, Palmdale 109 before sea breezes bring relief. Hot conditions spark three brush fires.

Temperatures skyrocketed across the San Fernando Valley by midmorning Friday, baking the area from Woodland Hills to Newhall in record-breaking temperatures as high as 111 degrees before dropping unexpectedly in midafternoon.

Weather forecasters said a high-pressure system caused the mercury to rise quickly before noon then fall several hours later.

In Burbank, temperatures climbed to 104 by 10 a.m. then dropped to 88 degrees four hours later. In sizzling Van Nuys, thermometers hit 111 degrees by 11 a.m. and fell 20 degrees by 2 p.m. Temperatures in Palmdale (109), Lancaster (107) and Newhall (104) all broke records.

Brush fires, pushed by gusting winds, exploded near Lancaster and Gorman. One of Lancaster’s two major blazes was still threatening homes late in the evening, Los Angeles County fire officials said.

The first serious fire of the day broke out at 3:30 p.m. near the intersection of 30th Street East and East Avenue J, east of Lancaster. About 100 firefighters, aided by two water-carrying helicopters, had the 350-acre blaze contained by late afternoon.

Nine minutes later and about 20 miles to the west, a fire broke out near Gorman on the northern rim of Los Angeles County. More than 150 firefighters fought the fire near the Golden State Freeway south of Gorman Road. By 8 p.m., that fire had grown to 600 acres and was deemed 40% contained.

A third fire, to the west of Lancaster near 90th Street West and West Avenue B, had consumed 600 acres and was still raging uncontained after sundown, said county Fire Inspector Greg Cleveland. Reported at 4:02 p.m., it was the only major fire in the county’s northern reaches that threatened homes, although none had burned as of 8 p.m., Cleveland said.

More hot weather is predicted for the weekend, with highs in the triple digits throughout the Valley.

“It’ll be almost a carbon copy of what we had today,” said Bill Hoffer, a specialist with the National Weather Service in Oxnard.

Warm winds, although they blew only 13 to 15 m.p.h. in Burbank, helped pull temperatures down, Hoffer said, adding that the 16-degree drop was not unusual in the presence of such a high-pressure system.

The system, which now extends over the western half of the United States, compresses the sun-heated air, preventing the cooler marine air from flowing into the Valley from the ocean in the morning. Later in the day, breezes sprang up carrying the ocean air, lowering temperatures, experts said.

But while the temperatures were dropping outside, they were rising in several parts of the Valley when electricity--and air conditioners--went out Friday afternoon.

At the Los Angeles Police Department’s Van Nuys Division, officers turned on fans and downed water and sodas while the air conditioning stayed off most of the day. “I’m sitting here with a fan and I’m still perspiring,” said Sgt. Paul McMillin, the watch commander. “It’s warm in here.”

The city Department of Water and Power reported several electrical outages affecting customers in Canoga Park, Sun Valley, Granada Hills and Van Nuys. Jan Merlo, a DWP spokeswoman, said the utility company typically keeps up with high demand for electricity but neighborhood transformers can become overloaded as residents switch on their air conditioners, stoves and other appliances at about the same time.

In Lancaster, a freak--and brief--rainstorm drenched residents in the afternoon. It was accompanied by tornado-like winds that knocked down utility poles, igniting a fire that burned more than 50 acres of brush.

The National Weather Service issued a severe thunderstorm warning for the northern portions of the county.

John Garcia said he was outside his Lancaster home with his dog near the intersection of Avenue J and 30th Street East when the storm quickly blotted out sunny skies.

“We heard the thunder and it got real cloudy all of a sudden, and then we saw dust in the distance,” he said. “I thought it was smoke from a fire because it was so hot.”

Several minutes of rain followed, accompanied by swirling, tornado-like winds that smashed in a garage door and scattered trash cans, Garcia said.

Downed lines from the poles ignited the fire in an empty field nearby, he said, adding that the storm left as quickly as it came.

“It was dust, wind, rain and then it was perfectly clear again.”

Elsewhere in the hot zone, scores of people visited the newly opened Six Flags Hurricane Harbor water park in the Santa Clarita Valley. Their arms and noses slathered with sunscreen, Garret Magarian, 9, his brother Steele, 10, and their cousin Skyler Burke, 8, tippy-toed frantically in their bare feet to avoid scorching their soles.

“I had the kids for the weekend,” said the youngsters’ grandfather, Ed Gagnon, 55, “so I thought I’d bring them here.”

Adjusting his shades, Brian Gagnon, the kids’ uncle, chimed in: “Tomorrow, we’re headed for the beach.”

While Six Flags will not disclose the number of patrons the desert heat chased to the water park, Hurricane Harbor was clearly bustling with weather refugees eager to splish and splash on the water rides.

Park patrons donned an assortment of footwear--from rubber sandals designed for kayaking to flip-flops adorned with images of Pocahontas--as they scurried from one attraction to the next.

“It’s pretty bad,” said Alex Carballo, 17, elated after swooshing down a 65-foot water slide aptly titled Daredevil Plunge.

Times correspondents Maki Becker and Mark Sabbatini contributed to this story.