Ships cross the Atlantic twice a year, moving between Europe and the Americas in spring and in fall. Most of the trip is sea days far from land, where there is no forecast for a port and the ship sets its own route around storms.
The northern route (via Iceland, Greenland, or the Azores) is cool and windy even in spring, and fall crossings run into the Atlantic storm track. Expect some days of heavy swell and closed outer decks. Motion-sickness remedies, a warm jacket, and non-slip shoes are worth packing.
Captains change course to go around a storm, which can mean a skipped or swapped port, most often in the Azores or Bermuda.