ORLANDO, Fla. — With Hurricane Helene having turned into a post-tropical cyclone but still dumping rain in the Ohio Valley and Southeast U.S., the National Hurricane Center turned its attention to two developing systems with growing chances to form into the season’s next tropical depression or storm while also keeping track of Hurricane Isaac and Tropical Storm Joyce in the Atlantic.

The most likely to threaten the U.S. is a system the NHC expects to form in the Caribbean that could head into the Gulf of Mexico.

As of the NHC’s 2 p.m. tropical outlook, forecasters predict an area of low pressure to form over the Western Caribbean in a few days.

“Environmental conditions are forecast to be conducive for gradual development thereafter, and a tropical depression could form around the middle part of next week. This system is expected to move northwestward into the Gulf of Mexico during the latter portion of next week,” the outlook stated.

The NHC gives it a 50% chance of development in the next seven days.

The warm Gulf waters were how Hurricane Helene picked up steam under similar circumstances, starting as a “potential tropical cyclone,” but then growing into a Category 4 major hurricane that devastated Florida’s Gulf Coast before striking the state’s Big Bend region and moving quickly up into the Southeast U.S.

The hurricane is blamed for at least 52 deaths including at least 11 in Florida.

Another system with moderate chances to develop this week is a broad and elongated area of low pressure associated with a tropical wave with disorganized showers and thunderstorms in the eastern Atlantic located west of the Cape Verde Islands.

“Environmental conditions appear conducive for gradual development of this system, and a tropical depression will likely form during the early or middle part of next week while the system moves toward the west and then northwest across the eastern and central tropical Atlantic,” forecasters said.

The NHC gives it a 30% chance to develop in the next two days and 70% in the next seven.

Also in the Atlantic, but no threat to land, are Hurricane Isaac and Tropical Storm Joyce.

As of the NHC’s 2 p.m. advisory, Isaac was a Category 2 hurricane with 105 mph sustained winds moving northeast at 20 mph located about 785 miles west of the Azores. Hurricane-force winds extend out 30 miles and tropical-storm-force winds extend out 150 miles.

“This general motion should continue through Monday followed by a turn toward the north-northeast on Tuesday,” forecasters said. “Little change in strength is expected through mid-day, followed by gradual weakening through the remainder of the forecast period. Isaac is expected to be a post-tropical cyclone on Monday.”

As of the NHC’s 11 a.m. advisory, Tropical Storm Joyce had sustained winds of 50 mph as it moved northwest at 10 mph located about 1,165 miles east of the northern Leeward Islands. Tropical-storm-force winds extend out 105 miles.

“A west-northwestward to northwestward motion with a decrease in forward speed is expected through Sunday. A slow turn toward the northwest and north is forecast Sunday night and Monday,” forecasters said. “Little change in strength is expected today. Weakening is forecast to begin tonight or on Sunday, and Joyce could degenerate into a remnant low by early Tuesday.”

The 2024 Atlantic hurricane season has had 10 named storms so far including two hurricanes, of which two became major hurricanes.

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