MIAMI – Tropical Storm Isaac is posing a potential threat to next week's Republican National Convention in Florida, which culminates in the nomination of Mitt Romney for president.
The U.S. National Hurricane Center on Wednesday morning said Isaac was expected to strengthen and could become a hurricane by Thursday.
Convention organizers knew it was a possibility during the peak of hurricane season. About 70,000 delegates, party officials, journalists, protesters and others are expected to attend.
It's been 90 years since a major hurricane made a direct hit on Tampa, the site of the convention. Florida, historically the nation's top target for tropical systems, has not been hit by a major hurricane since Wilma in 2005.
National Hurricane Center computer models had predicted Isaac would become a hurricane over the next few days, meaning maximum winds must be at least 74 mph. Some models had the storm striking Florida, including the Tampa Bay area, after moving across Cuba or the Bahamas as early as Sunday morning.
Jeff Masters, director of meteorology at Weatherunderground.com, said long-range storm track predictions five days in advance are notoriously inaccurate, often off an average of 260 miles. But Masters said the climate situation has improved chances that Florida could be in the system's sights during the Republican event that runs Monday through Thursday.
"It would take a perfect storm of a scenario where a bunch of factors all conspire together," Masters said. "But we definitely have to watch this one."
The storm's maximum sustained winds early Wednesday were near 45 mph. It was centered about 280 miles east of Guadeloupe and is moving west near 18 mph.
Tropical storm warnings were in effect for Puerto Rico, the U.S. and British Virgin Islands and a swath of islands across the Caribbean including Martinique, Dominica, Guadeloupe, St. Martin, St. Kitts, Nevis, Antigua, Barbuda, Montserrat, Anguilla, Saba, St. Eustatius, St. Maarten, Culebra and Vieques.
Republican and state officials have backup plans in place if the storm makes its way to Tampa, including an evacuation in a worst-case scenario.
A four-day mock hurricane drill was held in May featuring a pretend major storm striking the Tampa area during the second day of the convention. Under that scenario, planners canceled. A major hurricane is a Category 3 or above with winds at least 111 mph, and devastating damage can occur.