(Updated 9 a.m. EST) – Tropical Storm Karen, which appears to be heading toward Puerto Rico and the U.S. and British Virgin Islands, is causing some cruise ship itinerary changes.

The National Hurricane Center is forecasting the storm could arrive at the Virgin Islands by Tuesday, September 24. A tropical storm watch, with accompanying heavy rainfall, tropical storm force winds and flash floods, is in effect for the islands, as well as Puerto Rico.

The Virgin Islands Port Authority has said that Crown Bay Marina on St. Thomas will close at 3 p.m. today, September 23.

Here are the cruise ship changes reported so far. Cruise Critic will continue to update this story as needed.

Carnival

Carnival Fascination has changed its planned stop in St. Thomas on September 23. Instead, the ship will go to St. Maarten on Monday, a day earlier than anticipated. Other changes include moving up a planned stop in St. Kitts by one day and adding a stop in Dominica on September 25 before resuming the planned itinerary. Carnival Fascination left Puerto Rico on September 22.

Norwegian

Norwegian Breakaway stayed in San Juan overnight on Tuesday, September 24, canceling Wednesday's call in St. Thomas. The ship sailed from Miami on September 22.

Royal Caribbean

Passengers are reporting on Cruise Critic that Symphony of the Seas has changed its planned stops in St. Maarten and Puerto Rico for Tuesday September 24 and Wednesday September 25, replacing them with Cozumel and Perfect Day at CocoCay. The ship left Miami on Saturday, September 21.

Harmony of the Seas departed Port Canaveral on September 22 and will call at Perfect Day at CocoCay as planned, today. The ship will then switch to an Eastern Caribbean itinerary with a sea day tomorrow, September 24, followed by calls to Costa Maya on September 25 and Cozumel on September 26.