Cruise Lines Change Itineraries to Avoid Storm Dorian

alt — Forecast probability of tropical storm force winds, August 27. Red represents probability of 70 percent, increasing with darker colors (NHC)

Cruise lines are changing vessel itineraries in the Eastern Caribbean to avoid Tropical Storm Dorian, which may reach hurricane strength by Wednesday. A hurricane watch is now in effect for Puerto Rico and for parts of the Dominican Republic.

The cruise ships Allure of the Seas, Harmony of the Seas and Symphony of the Seas will all head for the Western Caribbean, according to Royal Caribbean. The Allure and Harmony, which both left Florida's east coast on August 25, will head for Cozumel. The Symphony of the Seas, which left Miami on August 24, will stay closer to home, skipping a call in St. Maarten and spending an additional day at sea before continuing on her itinerary.

As of Tuesday afternoon, Symphony of the Seas was in San Juan, Puerto Rico, one day ahead of her original schedule. The U.S. Coast Guard captain of the port for Sector San Juan had not yet announced port condition Yankee, a storm warning which would require most commercial vessels to depart or apply for an exception.

Carnival Cruise Line's Carnival Breeze will be skipping a port call in San Juan scheduled for Wednesday and spending an extra day at sea. Carnival Sunrise, which departed Tuesday from New York City, will switch the order of its itinerary and call San Juan on August 30, after the storm has passed.

Disney Cruise Line has announced that Disney Fantasy will head for the Western Caribbean, calling at Grand Cayman and Cozumel instead of her planned stops in Tortola and St. Thomas.

The storm's future intensity is proving difficult to forecast, according to the National Hurricane Center. Model predictions differ more than average, giving a "lower than normal confidence in the intensity forecast," especially four to five days out. Tropical storm conditions are expected and hurricane conditions are possible in Puerto Rico on Wednesday, the NHC said, and heavy rainfall may lead to flash flooding.

Further out in the week, the storm could bring heavy rain and high winds to mainland Florida and the Bahamas - but its intensity at that point remains uncertain.