How meteorologists played an important role in D-Day

CHICAGO - D-Day was one of the most important military campaigns in world history. What you might be surprised to know is the pivotal role meteorologists played in the invasion.

In the weather world, you could say this was history’s most important forecast.

The D-Day operation required a very specific set of conditions. It needed to take place shortly before dawn, on a rising tide, and preferably on a night with a full moon. Keeping those conditions in mind, there was only a shortlist of available dates, which included June 5-7.

Allied troops waited in camps across southern England, but the weekend of June 3-5 saw strong winds, low clouds, and rough seas. On Saturday, June 3, Gen. Dwight D. Eisenhower gave the order to postpone.

However, on June 4, crucial information was received from an Irish weather station indicating a ridge of high pressure would be building, meaning calmer weather was on the way.

So, in the early morning of June 5, Eisenhower met with his senior staff and decided it was time. If the invasion had been postponed again until the next available date, June 18, the results of the war could have been very different. That week, the worst storm in 40 years arrived in the English Channel, which would have made the landings impossible.

On the day of his inauguration, President John F. Kennedy asked Eisenhower what had given him the edge on D-Day. Eisenhower replied, "Because we had better meteorologists than the Germans."