Hurricane Debbie was the fourth tropical cyclone and the fourth named storm of the 1961 Atlantic hurricane season. Debbie is the only known tropical cyclone in modern history to landfall in Ireland while still tropical. The hurricane and its remnants were responsible for at least 11 deaths.
The precursor to Hurricane Debbie was observed by a weather station in Cape Verde as well as a ship in that area. It was classified as Tropical Storm Debbie late on September 7, the center was located about 550 miles (885 km) from the island of Sal. Upon classification, the maximum sustained winds were already near hurricane force. Tropical Storm Debbie quickly strengthened into a hurricane, though it was not operationally upgraded until September 11. Hurricane Debby strengthened slowly thereafter. Debby remained a weak, category 1 hurricane until September 11; at which time it had strengthened into a category 2 hurricane. It had quickly strengthened into a category 3 hurricane only six hours later.
Hurricane Debby had attained its maximum sustained winds later on September 11, which were at 120 mph (195 km/h). Debby would maintain this intensity for nearly 24 hours. As it began to gradually weaken as it turn to the east-northeast. The system began to accelerate as it approached the Azores. It passed through the Azores between the evening of September 14 and early on September 15. After passing through the Azores, Hurricane Debby began to take on some mid latitude cyclonic characteristics, thought had remained tropical. Hurricane Debby now began racing for Europe with a forward speeds greater than 45 mph (75 km/h). At this point, there was a possibility that Hurricane Debby became extratropical. On September 15, Hurricane Debby began to gradually turn northeastward. Over night between September 15 and 16th, a forward speed of at least 50 mph (85 km/h) was recorded.
Hurricane Debby made landfall in Dooega on Achill Island during the morning of September 16. Shortly thereafter, it had moved into the Irish mainland over County Mayo. Debby re-emerged into the extreme northeast Atlantic before being declared extratropical. The remnants of Debby tracked along the coast of Norway before entering Russia and dissipating on September 19.
When Hurricane Debbie made landfall in Ireland on September 16, it became the only known tropical cyclone to do so while tropical. Hurricane Debbie caused about 11 fatalities in Ireland. It was estimated that Hurricane Debbie and its remnants also injured at least 50 people. A few locations reported winds in excess of 100 mph (161 km/h), including at Balleykelly, Tiree and Snaefell. Strong winds were also reported from Bay of Biscay to location in northern Norway. Its remnants were also responsible for flooding in Ireland, Scotland and Wales. There were no reports on impact related to Hurricane Debbie in the Azores. Because its impact on land as a tropical cyclone was relatively light, the name Debbie was not retired. The name was subsequently re-used in 1965 and 1969 before taken off the list due revisions of the names in the 1970s.