Tropical Storm Isaac threatened the Caribbean on Wednesday with winds of about 45 mph. The storm was located about 140 miles east of Guadeloupe late Wednesday morning. Tropical storm conditions were expected over Puerto Rico and the U.S. and British Virgin Islands on Thursday, according to the National Hurricane Center, possibly strengthening into a hurricane. So far this year there haven’t been many major storms, but forecasters say there will be enough for what they call a “normal” year, which means there may be more hurricanes to come in August in September.

Cruise lines have been keeping a close eye on the storm, but few itineraries were altered by midday Wednesday. Royal Caribbean International changed its Aug. 19 sailing to the Western Caribbean instead of the Eastern Caribbean. Allure of the Seas, which departed Port Everglades on Sunday, August 19, will now visit Falmouth, Jamaica, and Cozumel instead of St. Thomas and St. Maarten. No further changes were made to Allure’s next sailing or any other cruises that depart Florida on Thursday, Friday, Saturday or Sunday. Royal Caribbean posts any changes on a weather alert on its website.

At midday Wednesday, a tropical storm warning is in effect for Martinique, Dominica, Guadeloupe, St. Martin, St. Maarten, St. Kitts, Nevis, Antigua, Barbuda, Montserrat, Anguilla, Saba, St. Eustatius, British Virgin Islands, Puerto Rico and the U.S. Virgin Islands. A hurricane watch is in effect for Puerto Rico, the U.S. and British Virgin Islands, and the south coast of Dominican Republic.