Autumn Makes Itself at Home as Front Arrives : Weather: Cool, brisk breezes prompt many to hunt up sweaters and light fireplaces. Choppy waves affect boaters and the few beach-goers.

Sweat shirts went on, windows went down and log fires were lit.

Sure as football and falling leaves, a chill dose of fall weather visited Orange County over the weekend--courtesy of a passing cold front that offered the year’s first taste of autumn.

Firewood business was as brisk as the air, while windy conditions and choppy waves kept the usual beach crowd at home and prompted the Coast Guard to issue a small-craft advisory for the offshore area beyond Santa Catalina Island.

“It’s getting that time of year again,” said Joanne TerBush, co-owner of A&L; Firewood in Costa Mesa.

But the autumn weather is not expected to last long. The cold front was already past the region, and meteorologists said temperatures that fell to the upper 50s should start rising again, possibly as early as today.

“I’m betting on a warming trend,” said Kris Farnsworth, a meteorologist for WeatherData Inc., which provides forecasts for The Times. Monday, though, is “the hardest day to figure out,” he said.

Overnight temperatures dipped Sunday morning to lows of 56 degrees at the El Toro Marine Corps Air Station and 57 degrees in Santa Ana--cool but normal levels for this time of year. The temperature reached a high of 76 degrees in Santa Ana on Sunday.

Farnsworth predicted that temperatures would rise slightly Monday and creep into the 80s by Tuesday. He said a new cold front could pass into Northern California by the end of the week, but doubted it would have much effect on Southern California weather.

Gas company officials saw little increase in the number of people calling to have their furnaces turned on, but Trudy Crawford, a supervisor at Southern California Gas Co., noted that the early birds took care of that during rainy weather two weeks ago.

“We haven’t gotten our first flood of calls yet,” she said.