FROM his office overlooking the surf in Huntington Beach, wave forecaster Sean Collins has been busy monitoring satellite reports of water temperatures off Mexico. From August through October, hurricanes in the eastern Pacific can push powerful south swells into Southern California, stoking surfers with consistent overhead waves for days at a time and resulting in an incalculable number of ditched algebra classes and canceled business meetings. (When the swells hit, "I hold all my board meetings in the water," Collins cracks.) But if that's to happen and for Collins to predict it on Surfline.com, the water off the tip of Baja must be warm enough to sustain a developing hurricane -- at least 80 degrees. Last summer was a dud, but in epic years, 10 hurricane-generated swells might roll through, sending surfers flocking to south-facing beaches such as Huntington Beach and Malibu. Collins still recalls the August 1997 swell generated by Hurricane Guillermo. "It was incredible," he says wistfully. "Huntington and Newport easily had 15- to 18-foot [wave] faces." So how's this season shaping up? Collins estimates Southern California will see at least two or three hurricane swells between now and the end of September. He utters the words all surfers want to hear: "Late August, September and October are looking promising."