Season’s First Santa Anas to Blow In This Weekend : Weather: Temperatures will rise, but the winds will be much weaker than those that drove last year’s wildfires. Authorities plan to monitor tinder-dry areas and take special precautions nonetheless.

The first Santa Ana winds of the fall are expected today, promising the return of summer-like heat and prompting county fire officials to take extra precautions against brush fires.

Meteorologists said the dry, desert winds could push Orange County temperatures into the 90s, but will be much weaker than Santa Ana winds that drove last year’s wildfires.

“It certainly will be a return to some of the warm temperatures after the cool weather,” said Harry Woolford, a meteorologist with WeatherData Inc., which provides forecasts for The Times.

Forecasters predicted winds of about 25 m.p.h.--half the speed of strong Santa Anas--lasting through the weekend. Forecasts called for inland temperatures to reach the upper 80s today and low 90s Saturday and the 70s and low 80s along the coast. Santa Ana winds--compressed by high pressure over the desert and shot through mountain passes toward the sea--bring arid, fast-moving air and the greatest danger of brush fires.

As a precaution, officials planned to dispatch added fire engines to even routine fire calls and to monitor three weather stations that track wind, humidity and temperatures in tinder-dry hills and wilderness areas. If conditions warrant, officials will position strike teams in sensitive areas and dispatch patrolling fire engines.

“Everybody’s sensitivity to these conditions was heightened by the Laguna Beach fire being less than a year ago,” said Emmy Day, a spokeswoman for the Orange County Fire Department.

Meanwhile, lifeguards braced for a return of summer-like crowds with reduced off-season staffing. Lt. Eric Bauer, a Newport Beach lifeguard supervisor, advised swimmers to stay near staffed lifeguard towers.