The only obstacle that seems likely to prevent Alberto Salazar from breaking his 1982 5,000-meters record in the Vitalis U.S. Olympic Invitational Saturday night could be snow. Weather conditions that threatened to turn much of the northeast into a snowdrift could keep Salazar away.

Salazar, who won the 5,000 meters last year in a time of 13:28.02, had arrived in the area Thursday to finish training, but was scheduled to make a promotional appearance for Nike at a Chicago trade show today. Concerned about the weather conditions and forecasts, he tried to change his schedule.

"I committed to this meet more than a year ago," he said Thursday afternoon, "and my primary responsibility is to the meet."

But the shoe manufacturer assured Salazar he would be flown back here tonight via private jet, promising to find a way for him to run Saturday night, in spite of poor weather.

Salazar, who predicted Thursday that he would break Suleim Nyambui's world indoor best of 13:20.4, said he is in better shape than he was at this time last year, and should be able to better that mark.

"I am a little concerned about getting back (from Chicago) but as long as I can get here, I don't think the travel will have that great an effect on my performance."

Last year, although Salazar won easily, he lost five seconds or more during the third lap when he was knocked down after getting entangled with Solomon Chebor and Don Cleary. Salazar had to rally from last place to win the event.

"I fell down and ran 13:23, which should mean I probably ran under 13:20," he said. "I'm going for the record and think I can set it regardless of anything, except another fall."

Nyambui will be in the field, but because of surgery last fall, is not likely to be in condition to present a serious challenge. Australian Robert DeCastella, whose marathon time of 2:08.18 is second only to Salazar's 2:08.13, has never run on an indoor surface. His outdoor 5,000 meter best is 13:24.2.

This marks the first meeting of Salazar and DeCastella, who said he is unsure just what to expect from the Meadowlands' 160-meter, Fiberglas-coated track. "It is my first indoor opportunity, and I guess the alternative is to run right to the front or right to the back," he said.

The women's events here will be minus Mary Decker Tabb, who announced Wednesday she would bypass the rest of the indoor season because of a stress fracture in her right ankle.

Miler Tom Byers, defending champion in that event, has also scratched. He has missed much of the indoor season with a bronchial infection. Although he had recovered from that, Byers said earlier this week that he doesn't feel he has been able to train sufficiently to compete at the level needed against runners like Eamonn Coghlan, Ray Flynn and Steve Scott.

Earlier this week, Coghlan returned from Ireland, where he attended his father's funeral. Coghlan, who has run the world indoor best of 3:50.6, said he is fit and ready to lower that time . . .

Billy Olson, who cleared 19 feet for an indoor best a week ago, won last year's pole vault with a meet record of 18 feet, 6 1/2 inches. If Olson, who is competing tonight in San Francisco, can overcome the logistics of getting here, that mark is likely to be bettered.