Tropical Depression Eighteen formed far in the Atlantic Ocean on Thursday and is expected to strengthen into a major hurricane — Category 3 or higher — by early next week. The forecast track shows the system, which would be named Tropical Storm or Hurricane Sam, tracking close to the eastern edge of the Caribbean by Monday afternoon. From there, it’s unclear where the storm will go. Here’s the latest forecast path, including the so-called “spaghetti models,” which show the paths predicted by the various forecast models: