Weekend to Bring Relief from Scorching Heat : Weather: Cool air from Alaska is expected to break 10-day heat wave.

The heat wave that has dragged on and on like a lousy movie will finally end this weekend, forecasters said.

Featuring hot temperatures and high humidity, the heat will end its 10-day run Saturday, when cooler air from Alaska is expected to move into San Diego, said Dan Atkin, a forecaster for the National Weather Service.

But a curtain call of above-normal temperatures is expected today, Atkin said. The beaches will be mostly sunny with a high of 77 degrees. The coastal area, including downtown, is expected to reach 81 today, about 4 degrees above normal, with overnight lows near 69.

Highs between 90 and 98 degrees are expected inland, where temperatures have regularly climbed over 100 degrees the last few days.

In the mountains and deserts, Atkin said, it will be partly cloudy with a chance of thunderstorms.

Highs in the deserts will reach nearly 110 degrees today, as during the peak of the heat wave, Atkin said. Lows of 64 degrees are expected tonight. The mountain high will climb to 90 degrees today, with a low of 64 degrees tonight.

By Saturday, the above-normal temperatures will begin to fall, Atkin said, as a cool stream of air from the Gulf of Alaska will push away the high-pressure system that has camped over San Diego.

The result: Temperatures throughout the county will drop 5 to 10 degrees Saturday, he said, adding that Sunday temperatures are expected to be about the same as Saturday’s.

The imminent passing of the heat wave was greeted with mixed emotions around the county.

The hot spell’s combination of warm temperatures and high humidity didn’t impress Atkin: “We didn’t break any records,” he said matter-of-factly.

The high of 88 at Lindbergh Field on Aug. 17 tied a record set in 1890, but didn’t break it, Atkin said.

He was, however, impressed with the heat wave’s staying power, which he said was “unusual.”

The heat wave’s longevity didn’t earn any praise from lifeguards.

“I am glad it is leaving, and I hope we don’t get another one,” said Ken Casper, 40, a lifeguard supervisor in Solana Beach.

The warm waters generated by the heat wave meant more swimmers and more rescues for Casper, who said he was nearly overwhelmed at times.