"If the prudent decision is to postpone the start of the event, then racing will be rescheduled to Saturday, where the weather forecast indicates great racing conditions," America's Cup Event Authority CEO Russell Coutts said in a statement.
Crews representing Britain, France, Japan, New Zealand and Sweden are seeking to win the right to challenge Oracle Team USA for the America's Cup, the oldest trophy in international sport, in Bermuda's Great Sound.
They are competing in 50 foot (15 metre) high-tech catamarans which can hit speeds of 50 knots (92.6 km per hour).
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The organisers said on the website of the 35th America's Cup that while the weather had been "excellent" for sailing all week and was forecast to be good on Saturday and into next week, winds were expected to gust above 30 knots on Friday. This ranks as "near gale" on the Beaufort wind force scale.
"Whilst the wind may drop within the raceable limits of 6-24 knots later in the evening, the safety of both the sailors and spectators is always paramount," it said, adding that a decision on whether to go ahead with racing may be made as late as Thursday evening, after an updated forecast.
(Reporting by Alexander Smith; Editing by John O'Brien)
