Debby became extratropical cyclone well west of the British Isles later on September 20, while the remnants were quickly absorbed into a larger storm system.

Overall, impact was generally minor in the Lesser Antilles, with only light to moderate rainfall in the Dominican Republic and United States Virgin Islands.

The system moved into this area as the latest reconnaissance aircraft was deployed, declaring it a tropical depression on September 13 near the Dominican Republic.

[1] The next reconnaissance aircraft that investigated the system discovered a minimal pressure of 1005 mbar (28.67 inHg) and winds of 45 mph (72 km/h) in the depression's center, prompting an upgrade to Tropical Storm Debby on the morning of September 14.

[1] Debby briefly decelerated to as slow as 5 mph (8.0 km/h) early on September 17 as another trough in the westerlies arrived and the system entered it.

During this time, Debby strengthened into a Category 4 hurricane, peaking with maximum sustained winds of 130 mph (210 km/h) and a minimal atmospheric pressure of 950 mbar (28 inHg) around 00:00 UTC on September 18.

[3] Early on September 19, Debby passed roughly 30 to 40 mi (48 to 64 km) south of Cape Race, Newfoundland, before accelerating to the east as fast as about 60 mph (97 km/h) on the following day.

However, about 12 hours later, as the system rapidly approached the British Isles, it transitioned into an extratropical cyclone approximately 580 mi (930 km) west of Ireland.

[4] However, meteorologists noted that the major storm system, which included the remnants of Debby, re-intensified over Ireland and later crossed Scandinavia, reaching northern Finland on September 22.

[11] Airlines canceled flights, buildings boarded up, and cruise liners were hurried out of their harbors in the time before Debby arrived.

[15] As the storm was approaching Canada, some oil rigs offshore of Newfoundland were evacuated and a science expedition off Grand Banks was discontinued.

Onshore, Debby produced light rainfall in the southeastern portions of Newfoundland, with precipitation peaking at approximately 3.5 inches (89 mm).

Winds over 100 mph (160 km/h) felled millions of cubic metres of forest, and a storm surge severely damaged the cities of Kemi and Tornio, claiming two lives.