SAN DIEGO – Winds of 25 knots and rough seas postponed the opening races of the third round-robin of the America’s Cup trials Tuesday and led the defenders to modify rules for rescheduling abandoned races.

The foul weather was the result of a storm that moved in Monday and drenched San Diego with 1.46 inches of rain by noon Tuesday. Sailing in such heavy conditions can cause serious damage to the carbon-fiber racing yachts.

The National Weather Service said a high-pressure system with clear skies is expected to move in Wednesday with suitable sailing conditions, winds of 10-18 knots and seas of two to four feet.

The foreign challengers will push back their series by one day, sailing Tuesday’s scheduled races on Wednesday, weather permitting.

Those races will be Sydney 95 vs. France3, Nippon vs. Team New Zealand and NZL-39 vs. Rioja de Espana. John Bertrand’s oneAustralia syndicate, which will debut its new yacht this series, has the first layday.

Weather postponements can cause significant havoc with the defender series.

The nine-race defender round-robins are sailed in sets of three races, in which each yacht sails once against each of its two opponents.

After consulting with the three syndicates on Tuesday, the Defense Committee decided that for the two remaining round-robins, the first two sets of races will be completed before the third set has started.

That means Tuesday’s scheduled race between Young America and the all-women America3 crew will be resailed on Monday, when the third set was to have begun.

Wednesday’s race will remain as scheduled, between Dennis Conner’s Stars & Stripes and America3.

In the second round-robin, two races were postponed in the second set and one was postponed in the third set. Since there were only two reserve racing days, the postponed race in the third set was made up, and the entire second set was wiped out.

That cost Stars & Stripes a second-set victory over America3 and two points in the standings.

As a result, Stars & Stripes entered the third round-robin tied for first with Young America with nine points. America3 is third with three points.

“The Defense Committee felt it best to maximize the chances that a race completed will be scored,” chairman Wytie Cable said. “It should be recognized, however, that a set of three must be completed before any of the races in that set are scored.”