Hurricane center ups odds for Caribbean-bound system while Tropical Storm Sean churns

The National Hurricane Center increased the chances a system bound for the Caribbean will form into the season’s next tropical depression or storm while Tropical Storm Sean continues to swirl in the Atlantic.

The developing system is a broad area of low pressure in the eastern tropical Atlantic several hundred miles south-southwest of the Cape Verde Islands producing limited and disorganized shower and thunderstorm activity.

“Only gradual development of this disturbance is expected during the next couple of days. Environmental conditions are expected to become more conducive for development by the end of the weekend while the disturbance begins to move westward across the central tropical Atlantic,” forecasters said. “Additional development is expected after that, and a tropical depression is likely to form during the early to middle portion of next week as the system moves steadily westward across the central and western tropical Atlantic.”

The NHC gives it a 10% chance to develop in the next two days and 70% in the next seven.

If it grows into named-storm strength, it could become Tropical Storm Tammy.

Tropical Storm Sean continues to churn in the Atlantic as well, but is no threat to land.

As of 11 a.m., the center of Sean was located about 1,180 miles west of the Cape Verde Islands in the mid-Atlantic moving west-northwest at 12 mph with maximum sustained winds of 45 mph. Tropical-storm-force winds extend out up to 70 miles.

“A turn toward the northwest at a similar forward speed is expected today. Sean is then expected to gradually slow down, turning back toward the west-northwest by Sunday,” forecasters said. “Additional weakening is anticipated. Sean will likely become a post-tropical remnant low over the weekend.”

It grew into the 19th tracked system of the 2023 Atlantic hurricane season this week, although only 18 have used names from the official storm list as January saw an unnamed subtropical storm.

If Tropical Storm Tammy were to form, the season’s initial 21-letter storm name list would have just Vince and Whitney left before having to delve into the World Meteorological Organization’s supplemental name list that starts with Adria. Only 2005 and 2020’s hurricane seasons needed to spill over into a second storm name list.

The hurricane season officially runs from June 1-Nov. 30, but storms that form outside that six-month run that are still in the calendar year are considered part of the season’s total.