David M. Shribman

Now, as we approach the 80th anniversary of the D-Day invasion that began the liberation of Europe from Nazi control, let us praise an obscure woman.

Her name was Maureen Sweeney, and she went to her grave at age 100 just six months ago—  her heroics noted by few, her legacy the small but indispensable contribution she made to the Allied war effort from a lighthouse on Blacksod Point in Ireland’s County Mayo. 

Her day job was working at the tiny local post office, a position she held until she retired two decades ago. But her real impact was in the weather information she passed, as a 21-year-old, to Gen. Dwight Eisenhower and the other Allied commanders who were about to send the largest amphibious force ever assembled onto the Normandy beaches. Her message can be distilled down to one word: Don’t.

She didn’t actually say that, but when she took the hourly barometric reading from the nearby lighthouse at 1 a.m., she noted dropping atmospheric pressure along with steady southwesterly winds and mounting rain — weather conditions that jeopardized the success of the invasion. Her report found its way to the D-Day planners, who swiftly telephoned the post office. She and the postmistress’s son, Ted Sweeney — whom she would marry after the war — confirmed the report. 

“It was all systems ‘go’ until that report from Ireland about the rough ocean seas and winds,” Douglas Brinkley, a Rice University historian who has written about D-Day, said in an interview. “In the pre-satellite era, this was the best weather information Eisenhower had at his disposal. He decided to wait a day, and if he hadn’t, it would have been a disaster. It would have been impossible to deploy armed forces on the beaches.”

It was one of the many moments when human wishes ran directly into the non-negotiable conditions of the weather.  

Typhoons in 1274 and 1281 spared Japan from invasion by Mongol fleets, giving birth to the term “kamikaze,” meaning “divine wind.” Russia twice was saved from occupation by winter conditions, first when minus-40 temperatures halted Napoleon’s march toward Moscow in 1812, and then when Adolf Hitler’s Nazi army repeated the folly in 1941. Unfavorable winds thwarted the Spanish Armada’s 1588 plans to invade England. Heavy rains fatally postponed an 1800 slave revolt in Henrico County, Virginia. Had there not been sunny skies over Hiroshima, and again over Nagasaki, in 1945, the city of Kokura, Japan — the backup target for both bombing sites — would have been devastated.

In 1944, the Blacksod Point reports of a falling barometer and strong winds prompted Group Captain J.M. Stagg, the British meteorologist assigned to the D-Day planning staff, to experience an onset of nausea. Shortly thereafter he told Gen. Eisenhower, Gen. Walter Bedell Smith, and British Air Marshal Arthur Tedder, “The fears my colleagues and I had yesterday about the weather for the next three or four days have been confirmed.” 

The invasion plan called for a three-day period of winds less than 13 mph, visibility of 3 miles, and less than three-tenths of cloud cover below 8,000 feet. The D-Day planners sat quietly, disappointed. Eisenhower later recalled that what he described as “formidable wave action” would have made an invasion a “most hazardous affair,” adding, “The meteorologists said that air support would be impossible, naval gunfire would be inefficient, and even the handling of small boats would be rendered difficult.”

So despite the fact that the troops were primed to go, the supreme Allied commander pulled the plug. That evening, U.S. Army rangers devoured a dinner of rancid hot dogs, and as a result, many of them were vomiting when they deployed. The rest of the force were merely impatient, many of them growing despondent, their anxiety deepening along with their fear. Their leaders knew that delay had dangers all its own.

Even so, they postponed the invasion by a day. “The order went out to call back the convoys,” Antony Beevor wrote in his 2009 account of D-Day. “Destroyers set to sea at full speed to round up landing craft which could not be contacted by radio and shepherd them back.”

The men of the 92nd Airborne already had been aloft. “We flew around for about an hour, and then word came that the invasion was called off for 24 hours due to the bad weather,” American parachutist Edward Boccafogli recalled. “They said that over the Channel (there) was one of the worst storms in many years.” The rain came so hard that three of the airmen’s tents collapsed, trapping them beneath the canvas. One was hit by lightning. 

The next night, as the commanders met in a library with rain and wind swirling outside, it appeared that the weather might break sufficiently with a 36-hour window of acceptable conditions, though there would be some cloud cover. “It’s a helluva gamble,” said Smith, “but it’s the best possible gamble.” Eisenhower asked Field Marshal Bernard Montgomery if he could see any reason not to proceed. He replied: “I would say — Go.” 

The American general paced, the rain and the winds continuing to batter the French doors of the planning headquarters. “It hardly seemed possible that an amphibious attack could be launched in such weather,” wrote Stephen Ambrose. Nonetheless, at 9:45 p.m., Eisenhower, worried that word of the invasion might leak and concerned about the morale of his men, delivered his verdict: “I am quite positive that the order must be given.”

It wasn’t until 1956, when the lighthouse was automated, that Mrs. Sweeney learned of her contribution to the war effort. And it wasn’t until three years ago that the United States officially thanked her for her work. The House of Representatives voted to present her with a medal and a certificate marking “her dedicated efforts leading to the success of the D-Day invasion of Normandy during the war that changed the world.” She received this honor when she was in a nursing home in County Mayo. She was 98 years old. 

Today, the green Department of Industry and Commerce Meteorological Service Station weather form remains. It stands as evidence of a young woman’s diligence, dedication, and eye for detail that saved the lives of thousands who, because of her effort and a single telephone call, did not join, in the words of Psalm 107, those “who go down to the sea in ships.”

A Swampscott High School Class of 1972 member, David M. Shribman is the Pulitzer Prize-winning former executive editor of the Pittsburgh Post-Gazette.