The weather dilemma that Ike faced is no secret. It was bad. Really bad. Go now, or go in two weeks. And if the weather is bad then, your next chance is in the Fall.
Ike relied on the meteorological advice of Group Captain Sir James Martin Stagg in moving the invasion from June 5th to June 6th. Ultimately, he decided to go on June 6th counting on Stagg's forecast that the weather would clear shortly following the landings.
As it would turn out, the weather on the secondary date would have made an invasion impossible.
In a quaint little corner of Portsmouth, England is a place known as The Southwick House, that served as the Supreme Headquarters for the Allied Expeditionary Force. Right now, it is the Royal Defence Police School. I had the fortune to visit the Southwick House last October, when they were having their annual Trafalgar Night Dinner. There I found out they still have the exact map that the invasion was planned out on:
Pardon the picture...I was dealing with a limited camera, less than ideal lighting, reflections of a plexiglass case, and several glasses of champagne. While this is amazing in and of itself, what made the hair on the back of my neck stand up was a map and a letter I found framed in the hallway. The map was a meteorological map of the England, the Channel and the northern coast of France on 20 June, 1944. The letter, marked "SECRET" and dated 21 June 1944, was a report from Stagg to Eisenhower detailing current weather conditions in Normandy. In the upper right corner there was some writing.
Thanks - I thank
the gods of war we
went when we did!
Seconded...thank you, Gods of War.