Keeping an Eye on Invest 94L for the Islands Next Week

The disturbance could gradually develop and organize as it nears the eastern Caribbean by late next week

Although the tropical disturbance west of Africa – designated Invest 94L – looks less together than a pan of scrambled eggs today, the environment ahead gives good reason not to overlook it as trade winds sweep it westward toward the islands for next week.

To be fair, only seven hurricanes have been documented in the Main Development Region east of the islands this late in the hurricane season (fewer than 5% of all post-October 13^th hurricanes), and more than half of those were reported in the 1800s when records are more dubious. So it’s not an area of the Atlantic we’d normally look to for tropical trouble. But if 2023 has taught us anything, it’s that hurricane season isn’t exactly following its traditional calendar.

A staunch high-pressure ridge centered across the Atlantic will whisk 94L westward through the deep tropics into next week, blocking the system from peeling off to the north like its recent predecessors.

Odds of 94L passing within 100 miles of a given location through next week based on overnight global model forecasts. Warmer shades indicate higher odds. Most of our reliable computer models move the disturbance or what comes from it toward the islands for the latter part of next week. Credit: Tomer Burg/University of Oklahoma.

Meanwhile, it will be moving over waters that are still topping 86°F (30°C), nearly as warm as any ocean water on the planet right now and nearly 2°F (1.1°C) above average, record warmth for the time of year.

While the waters set the stage, it isn’t until early to middle next week that the upper-level pattern kicks in to potentially tap this available fuel source. Most of our models indicate a conducive wind configuration for possible strengthening by the middle to latter part of next week as 94L or the tropical cyclone that forms from it nears the eastern Caribbean. With light wind shear, a pocket of ample moisture nearby, and a deep reservoir of warm water, it wouldn’t be a surprise to see an organizing storm approaching the Lesser Antilles as we close out next workweek.

As of Friday morning, the NHC was giving the disturbance a high chance of becoming a tropical cyclone by middle next week.

It's too soon to speculate on possible impacts, but for now interests throughout the Leeward and Windward Islands should follow the forecasts carefully into next week. It’s far too early to know if this will make it west of the islands (the overall pattern and time of year certainly wouldn’t favor it) so there’s no reason for us back on the mainland to be concerned at this point.

Sean back as a tropical storm, but likely short-lived

Sean has been waffling between tropical storm and tropical depression status over the past several days as it battles it out with persistent wind shear over the open waters of the central Atlantic.

It doesn’t appear Sean will be much more than a low-grade tropical storm as it moves into a drier, more hostile environment for the weekend. The forecast calls for Sean to collapse this weekend while staying well out to sea.