Central Atlantic disturbance 95L likely to develop » Yale Climate Connections

A tropical wave designated Invest 95L by the National Hurricane Center, or NHC, is speeding west-northwest at about 15-20 mph across the central Atlantic. The wave is expected to steadily develop this week, becoming a tropical depression or tropical storm by Thursday, when it will be nearing the northeastern Leeward Islands.

Satellite images on Monday showed 95L was well-organized, with plenty of spin and an increasing amount of heavy thunderstorm activity. The system had favorable conditions for development, with moderate wind shear of 10-15 knots, warm ocean temperatures of 29 degrees Celsius (84°F), and a moist atmosphere with a mid-level relative humidity of 70%. These favorable conditions are likely to remain in place for most of the week, and 95L has strong model support for development.

Steering currents favor a continued west-northwest motion for 95L this week, which would likely take the core of the system a few hundred miles to the northeast of the Leeward Islands on Thursday or Friday. However, it is too early to rule out a track through the islands, and 95L will be capable of bringing heavy rains and gusty winds there even if the center of the system passes to the northeast. Intensity forecasts for 95L by late in the week are all over the place, varying from a tropical depression to a major hurricane. We will have to wait until the system consolidates before gaining forecast clarity on how quickly it might develop. After 95L passes the Leeward Islands, Bermuda is likely to be the only other land area that needs to be concerned with the system.

In their 8 a.m. EDT Monday Tropical Weather Outlook, the National Hurricane Center gave 95L 2-day and 7-days odds of development of 50% and 70%, respectively. The next name on the Atlantic list of storms is Jerry.

The 2025 Atlantic hurricane season is hitting for power, not average

The Atlantic hurricane season has had nine named storms, four hurricanes (Category 5 Erin, Category 4 Gabrielle, Category 5 Humberto, and Category 2 Imelda), and three major hurricanes. The 1991-2020 averages by this point in the season are 11.6 named storms, 5.5. hurricanes, and 2.5 major hurricanes. So, although we are below average for named storms and hurricanes, the fact that we have had an above-average number of major hurricanes has pushed the accumulated cyclone energy (ACE) index close to average (91% of average). Typically, about 20% of hurricane season activity remains after October 5^.

Bob Henson contributed to this post.