Invest AL92 Likely to Become Tropical Storm Gabrielle, Forecasters Say

A tropical disturbance in the central Atlantic designated Invest AL92 has a 90 percent chance of developing into a tropical cyclone over the next seven days, the National Hurricane Center said Tuesday, raising the prospect that the system will be named Tropical Storm Gabrielle and could strengthen into a hurricane.

The system is centered in the central tropical Atlantic and was moving west at about 17 mph. The NHC said a tropical depression or tropical storm is likely to form within the next day or two. A tropical depression is defined as an organized low‑pressure system with sustained winds of 38 mph or less; a tropical storm has sustained winds of 39 to 73 mph and receives an official name as it approaches hurricane strength.

Forecast models analyzed by forecasters show the developing system moving into an environment favorable for further organization, with several model runs indicating a turn to the north well before the system would reach the Caribbean. Forecasters cautioned, however, that model guidance is not uniform and some effects cannot be completely ruled out for islands in the eastern Caribbean or for Bermuda until the track tightens.

Fox Weather meteorologist Ian Oliver told USA Today that the disturbance is "very likely to organize into Tropical Storm Gabrielle sometime during the middle or latter part of this work week, and it will likely continue to intensify into a hurricane." The NHC reiterated that extra uncertainty remains while the system is still developing and advised interests in the Atlantic, Caribbean and eastern U.S. seaboard to monitor forecasts.

The prospective formation would mark an end to an unusually quiet stretch in the Atlantic basin that included the climatological peak of the hurricane season on Sept. 10. Climatological patterns and agency forecasts underline that the season is not over: the NHC notes that about 60 percent of Atlantic tropical activity typically occurs after Sept. 10, and historical records show roughly two‑thirds of activity between Aug. 20 and Oct. 10.

Scientists point to unusually warm waters in parts of the Atlantic basin as a factor increasing the potential for additional development. Jennifer Francis, an atmospheric scientist at the Woodwell Climate Research Center, told ABC News last week that waters in the Gulf and Caribbean are "very warm." NOAA issued an August forecast calling for above‑normal activity for the remainder of the season, and the Climate Prediction Center's latest Global Tropics Hazards and Benefits Outlook released last week predicted a heightened risk of tropical cyclone formation beginning Sept. 17.

The NHC and other forecasting agencies will continue to release regular updates as the disturbance organizes and as model guidance evolves. For now, the most likely scenario from current guidance is formation of a named storm in the Atlantic this week with subsequent intensification, but forecasters emphasize that exact timing and future track remain subject to change as atmospheric conditions evolve.