Obituary: The diligent Irish postmistress whose weather report delayed D-Day 

It was her characteristic diligence and attention to detail that pinpointed the Atlantic storm which delayed Operation Overlord, or the D-Day landings as they are known, by 24 hours. The decision not only saved the lives of countless troops but eventually helped to secure an Allied victory in World War ll.

When Maureen sent her report of a big drop in barometric pressure to Belmullet that night, she thought no more of it. Unknown to her, it found its way — via Dublin and the UK Met office in Dunstable — onto the desk of D-Day’s chief meteorological officer, Captain James Stagg.

Blacksod lighthouse in Co Mayo, due to its location in the extreme west, was the only meteorological centre to pick up the rain, Force 6 winds, and low-level cloud that was sweeping in over the Atlantic. Captain Stagg could see that it would track over the English Channel and severely affect the planned invasion.

The phone rang in Blacksod around 11am the next day and Maureen Flavin was asked to check her readings. She recalled later that a woman with an English accent rang twice to ask for clarification. Maureen and lighthouse keeper/meteorological observer Ted Sweeney checked and rechecked the readings, but the figures came back the same.

Meanwhile, there was deep concern at the headquarters of the Allied Expeditionary Force. The conditions signalled by Blacksod would hobble an invasion planned for June 5. Rain and high winds would make the seaborne landings of ships and tens of thousands of troops extremely difficult, while low cloud would effectively render useless the thousands of assembled aircraft.

After fevered discussion, General Dwight Eisenhower decided to delay the operation. The change of plan had enormous consequences. It involved the disembarkation of thousands of troops; it increased the risk of discovery by the enemy and it had implications for ideal tide and moon conditions.

While much has been written about the Blacksod readings that delayed D-Day, Maureen Flavin and the man who would become her husband, Ted Sweeney, were also responsible for forecasting clement weather on  June 6 which allowed D-Day to go ahead.

As Maureen mordantly put it several years later: “They could arrange everything, but they couldn’t pre-arrange the weather.” When she died on December 17, aged 100 and a half — her family makes a point of counting the half — she was celebrated around the world as the woman whose weather report helped to change the course of history. When she was 98, she was awarded a special US House of Representatives honour. Now, An Post is planning to design a postmark in her honour.

But Maureen Sweeney was much more than the readings that brought her fame and accolades. She was a diligent postmistress, mother, grandmother, great-grandmother and great-great grandmother who made a lasting contribution to her community at Blacksod in Co Mayo, even if she never forgot her Kerry roots.

She was born on June 3, 1923 in Knockanure, north Kerry. In her late teens, she was due to emigrate to America when Blacksod post office advertised for an assistant clerk. An extra pair of hands was needed during World War ll as the post-office had been asked to take hourly weather readings, around the clock, which were then secretly telephoned to London to help the Allies.

Ted Sweeney, son of the then post-mistress Margaret Sweeney, told Maureen of the vacancy. The couple had met at a dance in Kerry. Maureen applied and got the job. She didn’t get to go to America, but the locals quipped that Blacksod, being the most westerly point in Ireland, was “the next parish”.

When Margaret Sweeney retired, Maureen took over the post office and the accompanying weather-reading duties. Ted was the lighthouse keeper at Blacksod and the couple married in 1946. They had four children, Ted, Gerry, Vincent and Emer. Two of them, Ted and Gerry, went on to work as lighthouse keepers at Blacksod. A grandson, and Gerry’s son, Fergus Sweeney now gives tours at the lighthouse’s visitor centre.

Fergus Sweeney recalls Maureen as a lovely granny — and much more: “She was a very strong woman. She was very much her own person and we were very proud of her.”