The season's first Santa Ana winds began to develop, fire weather warnings, forecasts of cold temperatures in valleys, and even a high-wind alert on the San Diego-Coronado Bay Bridge were issued Saturday.

A ``fire weather watch'' was issued for all of Southern California except the deserts Saturday, as a combination of typical autumn weather conditions sent winds flowing out to sea, drying the air and bringing scattered gusty winds. The fire watch will remain in effect for coastal Southern California through Tuesday evening due to the gusty northeast winds and low humidities.

The National Weather Service said Red Flag Warnings were likely either late Saturday or Sunday morning. Red Flag Alert days occur when the wind speed is 25 mph or greater, and the relative humidity is 15 percent or less.

Although no Red Flags were up Saturday, high pressure developing over Nevada will cause Santa Ana Winds to develop across the area through Tuesday, the NWS said.

The strongest of these winds is expected to be Monday and Tuesday mornings, when gusts as high as 60 miles an hour are possible in the mountains.

Forty-five-mph winds are also expected below passes and canyons of Los Angeles and Ventura County coast and valleys.

Very low humidities, dropping into the single digits, will precede the winds.

Los Angeles City Fire Department officials said they were consulting with federal meteorologists and taking their own wind and humidity readings in the hills surrounding the San Fernando Valley. The city drafts a Burning Index to the determine where to place extra fire trucks throughout Los Angeles.

The Burning Index is based on factors that include fuel moisture readings provided by a fire station that are matched to predicted fire weather information -- such as high/low temperatures, humidity, wind speed and direction. That information is provided by the Riverside-based Fire Weather Center, a group of federal meteorologists that specialize in fire weather predictions, the fire department said in a news release.