Meteorologists have been tracking the storm for the past week, with its chances of forming increasing gradually. Tropical Storm Sara is expected to form by Thursday morning, becoming a hurricane by Friday night and a major hurricane by Saturday night, AccuWeather said.

A hurricane watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.