A tropical depression is likely to form in the Atlantic from a wave rolling toward the Caribbean, National Hurricane Center forecasters said Thursday.
The expected depression, located 365 east of Barbados, immediately triggered tropical storm warnings across the Windward Islands covering Martinique, the Grenadines, St. Lucia, St. Vincent and Barbados. Sustained winds topped 35 mph as the system rolled west at about 17 mph, forecasters said in their 11 a.m. advisory.
The storm is expected to head across the Lesser Antilles over the next 24 hours and into the Caribbean Sea on Friday. It does not pose a threat to Florida, but forecasters warned the storm could dump between two and four inches of rain over the Windward Islands, triggering dangerous floods and mudslides.
It’s expected to steadily strengthen over the next week, but then weaken once it encounters higher wind shear in the central Caribbean, forecasters said. Models show the storm tracking to the northwest, and reaching the eastern Caribbean over the next day or so.
A new designation of a ‘potential depression’ allowed forecasters to begin issuing a track map with advisories even before the storm is officially labeled.
Meanwhile, a second wave in the central Atlantic more likely to threaten Florida also became better formed Thursday. In their 2 p.m. advisory, forecasters said over the next day or so, it’s possible this system could also become a cyclone and upped the odds of it forming to 60 percent over the next 48 hours.
The system was located about 1,200 miles east of the Leeward Islands, which it will likely reach by the weekend. As it nears the islands, conditions become less favorable so it’s possible it could weaken again. The system was headed west, northwest at about 20 mph.
Forecasters are also watching a third wave rolling off Africa’s west coast, which they say could also become a cyclone as it heads west about 15 mph.
Having three storms on their radar is not unusual for forecasters at this time of year when the Atlantic basin typically produces its highest number of hurricanes. Mid August usually marks the beginning of the uptick, with storms historically peaking on Sept. 10.
An earlier version of this story incorrectly stated the system had been designated a depression.
Follow Jenny Staletovich on Twitter @jenstaletovich