The most important weather forecast in History: D- Day

The weather was a key factor when planning the infamous invasion of Normandy, code named â??Operation Overload.â??

As we look back on the 70th anniversary of one of the biggest events for the Allies in World War II, many people are not aware the air and sea invasion of Omaha Beach in Normandy, France was halted by inclement weather.

The weather was a key factor when planning the infamous invasion of Normandy, code named â??Operation Overload.â?? It played a vital role because American troops were coming by both sea and by land and needed a certain set of conditions to storm the beaches

The original date for the invasion was 5 June 1944. General Dwight D. Eisenhower relied on three teams of meteorologists, one from the United States and two Britain, to give him forecasts leading up to D-Day. General Eisenhower met with meteorologists in the days leading up to the invasion. By most accounts, the team of American meteorologists gave the operation the green light for June 5, however, the two teams of British meteorologists, led by chief meteorologist who went by the name Group Captain James Martin Staggs, made the decision to halt the invasion of the beaches of Normandy because weather conditions would make the mission almost impossible to complete. With near hurricane force winds and harsh waves, the soldiers who would storm the beaches the next day, were forced to spend the night, seasick, on their landing crafts off shore, waiting for better weather for the mission.

These meteorologists were some of the best of their time, but they did not have the type of technology that meteorologists use today. They did not have satellites and radars, they relied solely on surface observations to produce a forecast that typically only went out a day or so. However, these meteorologists were at a disadvantage because Omaha beach was on the west side of France and there wasnâ??t observations over the Atlantic Ocean.

On June 6 1944, General Eisenhower gave the orders to begin the invasion of Omaha Beach (and four other beaches) in Normandy, France. While weather conditions were not ideal, June 6 was the only option otherwise they would have had to wait until late in June for the invasion.

In a top secret letter to another U.S. General, Eisenhower alludes to the poor weather conditions on June 5 and how they improved enough for the invasion to start the next day.

The weather on June 6 was cloudy with choppy waters. While these were not the ideal conditions that Gen. Eisenhower wanted, the invasion was still able to continue.

Other factors played a role in the invasion as well. Those were the phases of the moon, tides and the time of day. All of these were important because the amphibious landing vehicles needed the right conditions to move from the sea onto the beaches.

Years later President-elect John F. Kennedy asked President Eisenhower how the invasion of Normandy was so successful and Eisenhower answered, â??Because we had better meteorologists than the Germans!â??

Weather also played a vital role other big events during World War II including the dropping of the atomic bombs over Japan.