Hurricane Lee Peaked at 165 mph, Marking Atlantic’s Fifth-Fastest Intensification
Hurricane Lee ranked among the Atlantic basin’s most intense storms of 2023, reaching Category 5 status on September 8 after it explosively intensified over open ocean waters. The cyclone formed on September 5 from a tropical wave east of the Caribbean and strengthened from a tropical storm into a major hurricane within about 48 hours. Lee reached peak winds of 145 knots (165 mph) near 17.8°N, 53.5°W, with a minimum central pressure of 926 mb (hPa). The storm later weakened and expanded into a large post-tropical system that brought damaging winds, coastal flooding, and heavy rainfall to parts of Nova Scotia, New Brunswick, and Maine.
Tropical Wave to Category 5: Lee’s 72-Hour Explosive Rise
Hurricane Lee originated from a tropical wave that moved westward from the African coast in early September 2023. The disturbance initially produced scattered convection, but a developing mid-level circulation emerged near the Cabo Verde region on September 3. By September 5, satellite imagery and surface observations showed a more organized circulation center, leading to the formation of Tropical Depression Lee at 1200 UTC.
Lee strengthened into a tropical storm six hours after formation as thunderstorms consolidated around the center. The storm moved west-northwestward across the tropical Atlantic, entering waters with sea-surface temperatures exceeding 28°C. Mid-level moisture remained abundant, while vertical wind shear stayed below 10 knots, allowing the cyclone’s inner structure to rapidly organize.
The storm’s intensification rate surged on September 6 and 7. Lee became a hurricane only about 24 hours after reaching tropical storm status and became a major hurricane within approximately 48 hours. Its winds surged by 80 mph (130 km/h) in 24 hours, making the storm the fifth-fastest rapid intensification event on record in the Atlantic basin at that time.
By early September 8, Lee developed a well-defined eye surrounded by deep convection. At 0600 UTC, the hurricane reached its maximum intensity as a Category 5 system. The storm was located near 17.8°N, 53.5°W, several hundred miles east of the Lesser Antilles, with maximum sustained winds of 145 knots (165 mph) and a minimum central pressure of 926 mb (hPa).
The peak intensity placed Lee among the most powerful Atlantic hurricanes of the 2023 season. However, the cyclone remained over open waters during its Category 5 phase, avoiding direct impacts on Caribbean islands while continuing to evolve over the western Atlantic.
Peak at 926 mb, Then a Giant Wind Field: Lee’s Evolution Across the Atlantic
After reaching Category 5 strength, Hurricane Lee encountered increasing southwesterly wind shear that disrupted its compact inner core. The storm weakened rapidly after its peak and dropped below major hurricane intensity on September 9 while maintaining a west-northwestward track.
Despite losing peak intensity, Lee remained a large and dangerous system. The hurricane reorganized on September 10 as its eyewall convection became more concentrated, allowing it to strengthen again. Early on September 11, Lee reached a secondary peak with maximum sustained winds of 105 knots.
During this period, Lee underwent eyewall replacement cycles observed through aircraft reconnaissance and satellite data. These structural changes redistributed the storm’s strongest winds outward. By September 13, tropical-storm-force winds extended up to roughly 100 nautical miles from the center, creating a broad area of hazardous marine and coastal conditions.
Lee’s movement also began to change as atmospheric steering patterns shifted. A weakening subtropical ridge and the approach of a large-scale trough over the northeastern United States helped turn the hurricane northward. The system continued to weaken gradually while accelerating toward the western Atlantic coastline.
By September 14 and 15, Lee had weakened to a Category 1 hurricane while maintaining a broad circulation. The storm’s large wind field remained central to coastal impact forecasts.
Post-Tropical Lee Made Landfall in Nova Scotia With 70-mph Winds and Flooding
Lee transitioned from a tropical cyclone into a post-tropical system on September 16 as it moved into cooler waters and interacted with the mid-latitude atmosphere. Although the storm no longer possessed a tropical core, it maintained strong winds and a broad circulation capable of producing significant weather impacts.
The system affected Nova Scotia, New Brunswick, and Maine with strong winds, heavy rainfall, coastal flooding, and widespread power outages. In Nova Scotia, communities experienced downed trees, damaged infrastructure, and transportation disruptions as the storm moved through the region. Coastal areas faced elevated water levels and rough marine conditions caused by Lee’s large circulation.
Maine also experienced impacts from Lee’s passage, including strong wind gusts, rainfall, and coastal hazards. The storm’s broad wind field allowed effects to spread well away from the center, demonstrating how a weakening tropical cyclone can continue producing dangerous conditions after losing hurricane intensity.
Lee continued northeastward after crossing Atlantic Canada and completed its transition into a fully extratropical cyclone. The system dissipated over the North Atlantic on September 18, with its final tracked position recorded near 51.5°N, 53.1°W.