For a few tense days in June 1944, the success of the greatest military invasion the world had ever seen depended on weather readings taken by Maureen Sweeney at the remote Blacksod weather station on Ireland’s west coast. Maureen’s data threw Eisenhower’s meticulously planned invasion strategy into chaos, forcing him to mediate between opposing US and UK weather advisers and Generals and ultimately leaving him alone to make one of the most difficult decisions of the entire war. Completely unaware of the significance of her work - she was simply doing her job - Maureen’s readings were the first to point out an impending storm which led to the postponement of the invasion.

Then, in an impossibly dramatic twist, her readings were the first to pinpoint a short window of opportunity that Eisenhower needed to launch the invasion, thereby changing the course of the war.