Maureen Sweeney predicted that a storm from the Blacksod Lighthouse was imminent in 1944. This remote lighthouse, and coastguard station played an integral in supplying Britain and the US with weather reports during WWII.
These predictions inadvertently gave the Allies a two-day warning of stormy conditions across Western Europe, which delayed General Dwight D Eisenhower's Normandy invasion.
Ms Sweeney was just 21 years old when she forecasted this severe Atlantic storm at 1pm on 3 June 1944, leading to a subsequent change of plan by the Allied Forces, postponing D-Day until June 6.
Maureen Sweeney was awarded a special US House of Representatives honour for her role in changing the course of this war in 2021.
According to Ms Sweeney's family, she died peacefully at a nursing home in Belmullet in Co Mayo.
Born in Co Kerry, Ms Sweeney moved to Blacksod, co Mayo aged 18.
