The National Hurricane Center has designated the strong disturbance moving through the central Atlantic as Potential Tropical Cyclone Five. This procedural decision allows for the issuance of watches and warnings for a system expected to develop into Tropical Storm Ernesto before it reaches the easternmost Caribbean islands on Tuesday.
A Tropical Storm Warning is currently in effect for Puerto Rico, US Virgin Islands and the Leeward Islands, from north of Dominica westward to Anguilla, anticipating tropical storm conditions (winds of 39 mph or stronger) within the next 36 hours, where there is a possibility of winds exceeding 39 mph within the next 48 hours. These watches are likely to be upgraded to tropical storm warnings later on Monday as the system approaches the islands.
Air Force hurricane hunters investigating the system this morning have found a broad and still disorganized wind field, with no signs yet of the well-defined circulation needed to upgrade the system. However, winds are already strengthening on the northern side.
The official forecast predicts that the disturbance will develop into a tropical depression by early Tuesday, although it may skip the depression stage altogether and become Tropical Storm Ernesto before entering the northeastern Caribbean by Tuesday afternoon.
While wind gusts over 50 mph are possible as the system nears the U.S. territories early Wednesday morning, the primary threats to Puerto Rico and the U.S. Virgin Islands are expected to be heavy rainfall, flash flooding, rapid river rises, and the potential for landslides and mudslides in areas of higher terrain.
Future Ernesto is expected to turn east of the mainland U.S. but could pose a threat to Bermuda.
Like many of the early systems in 2024, the disturbance expected to become Ernesto is moving quickly. Its rapid pace from the east is contributing to easterly wind shear—a deviation from the more common westerly wind shear typically seen in deep tropical systems—hindering its short-term development.
By midweek, the developing system will reach the western edge of the Bermuda High, which is steering it westward and beginning to slow it down. As it makes a sharp right turn north of the Dominican Republic over the western Atlantic, more significant strengthening is expected to begin. By the end of the week, Ernesto could become a powerful Category 3 hurricane as it curls northward toward Bermuda for the weekend.
This late-week shift will keep future Ernesto well east of the United States. However, depending on its size and strength, dangerous swells could reach the Eastern Seaboard later this week or next weekend.
