Stormy weather threatens Obama's convention speech

Meteorologists are predicting possible thunderstorms over Charlotte, North Carolina on Thursday when President Barack Obama will address a crowd of up to 74,000 in a football stadium at the end of the Democratic National Convention.

The development comes after Tropical Storm Isaac forced the Republicans to cancel the first day of their gathering in Tampa, Florida.

The National Weather Service predicts a 30 percent chance of thunderstorms on Thursday night, when Obama is due to give his nomination acceptance speech at the Bank of America stadium around 10 pm EDT.

Although Obama's speech could be delayed or brought forward by a few hours, the change would wreak havoc with TV network schedules and possibly bump the address from prime time.

The bad weather is the lasting impact from Isaac, which spared Tampa but turned into a hurricane before hitting Louisiana.

Though the chances of storms are slim, the danger of lightning has rattled convention organizers.

An option for the Democrats could be to relocate the speech from the football stadium to Charlotte's Time Warner Cable Arena, where most of the convention is being held this week.

However, that indoor venue only holds around 19,000 people, potentially leaving more than 50,000 Obama supporters stranded on Thursday night.