Royal Wedding: Rain in the Forecast for Prince William and Kate Middleton

VIDEO: Katie Nicholl on the possibility of bad weather for William and Kates
WATCH Rain on the Royal Wedding Day?

Despite predictions last week that the sun would shine on Prince William and Kate Middleton's royal wedding day, updated forecasts now show the weather taking a turn for the worse.

The Met Office, the United Kingdom's national weather service, predicts strong winds with a likely chance of heavy showers Friday.

While superstition states that wedding-day rain is good luck, William and Middleton will surely be disappointed if their big day gets rained out. More than 2 billion people are expected to watch the royal wedding, and 600,000 tourists are flocking to London this week to catch a glimpse of the spectacle. A sea of umbrellas covering the wedding guests, royal family, bridal party, and William and Kate will surely block the best views.

ABC News royal contributor Katie Nicholl said it wouldn't be a royal wedding if there weren't several contingency plans. If it rains, the entire royal procession will travel to Buckingham Palace in covered coaches, a St. James's Palace spokesman confirmed. Prince William and his bride will take the Glass Coach, the same carriage in which Princess in to her wedding at St. Paul's Cathedral.

As for the royal couple's first kiss on the balcony of Buckingham, the Daily Mail reports a royal aide's insisting that the kiss will take place "'virtually no matter what ... with no plans to alter the timing."