The long-term warm cycle of the Atlantic multi-decadal oscillation (+AMO) began in the middle 1990’s. During 1995-2024, seasonal activity increased dramatically compared to long-term averages. However, in 2025, seasonal activity (assuming Gabrielle reaches hurricane strength) is one of the lowest amounts for late September in the 30-year climatology. The least total amount of hurricanes observed since 1995 was 2 in 2013 and 3 in 1997 and 2009.

The heat release of Gabrielle into the higher latitudes could cause an amplified blocking high pressure over Greenland in 2 weeks as supported by the negative North Atlantic oscillation (-NAO) forecast suggesting a weather pattern change for both North America and Europe.

ECM “weeklies” reign number one predicting the 500 MB height pattern across North America for the week 2-4 outlook during the past 30 days.

A tropical disturbance in the east-central North Atlantic basin is developing. A tropical cyclone is likely by midweek. Upper shear northwest of this system may slow significant development. This system will stay well out to sea. Otherwise, no significant tropical cyclone risks exist in the 10-day outlook.