Deep tropics waking up as we enter the heart of hurricane season

Like clockwork, our eyes are drawn to an active disturbance near Cabo Verde. "Cabo Verde season", in fact, gets its name for the constant march of easterly waves that exit the African coast and begin their westward trek across the deep tropics... some of which become long-track tropical cyclones -- most prolifically from mid-August through early October.

Invest 96L is currently centered about 200 miles south of Cabo Verde and has very good odds of becoming the next named storm of the season, Dolly. Models are in good agreement on a west-northwest track for the next 4-5 days, then there is some notable divergence. The forecasts with weaker intensities tend to stay on a west-northwest track, bringing it near the northern Leeward Islands by about Sunday, while the forecasts with stronger intensities tend to start turning it toward the north around that time.

If it takes the more northern route, Bermuda should be on alert late next week. However, even if it does take the more southern route, conditions could become more favorable for development as it passes north of Puerto Rico and Hispaniola, and places like the Bahamas, Cuba, and Florida should be watching this very closely for mid-late next week. The skillful Google DeepMind ensemble has been showing that scenario, though it's too far out now to be too concerned.

The Google DeepMind ensemble, showing forecast tracks from what is currently Invest 96L. All members fail to develop it until this weekend, then several of them do near the Bahamas around next Wednesday. The positions of the low pressure centers shown here are on Thursday evening (September 3). The colored background image is the sea surface temperature.

Later this week, this could become the first hurricane of the season. Over the past five decades, the median date of first hurricane formation is August 6. In recent years, we have had some much later first hurricanes: September 2 (2022), September 11 (2013), and September 11 (2002), so this is far from record late in the season.

Elsewhere, Invest 95L is located northeast of Bermuda and also has a chance of becoming a named storm, though its window for development is not very long. After Dolly, the next name is Edouard. Both Dolly and Edouard have been on the rotating list of names since 1996 (Dolly since 1996 and Edouard since 1984).

If it does manage to develop, it would remain fairly weak and track toward the north-central Atlantic... perhaps becoming relevant to the British Isles in 5 days or so as an extratropical cyclone.

• Visit the Tropical Atlantic Headquarters.
• Subscribe to get these updates emailed to you.
• Follow me on Bluesky