In January 1944, General Dwight Eisenhower was appointed commander of Operation Overlord. In the months and weeks before D-Day, the Allies carried out a massive deception operation intended to make the Germans think the main invasion target was Pas-de-Calais, the narrowest point between Britain and France, rather than Normandy. But did you know that D-Day was scheduled a day ahead?
Meteorologists James Stagg convinced Dwight Eisenhower to postpone D-Day by one day abruptly. The planners considered the tide, wind speed, and even the moon cycle when determining the ideal weather conditions for the landings.
How The Weather Changed The Dates?
Britain’s known to be incredibly unpredictable, but in the summer of 1944, it almost cost the Allies dearly. They had intended to launch the strike on June 5, but James Stagg, a meteorologist, intervened to avert a massive catastrophe.
The invasion had to happen under exact circumstances. The English Channel required low tides, moderate wind, and calm conditions. Additionally, the date needed to be as near a full moon as feasible. Eisenhower’s response to James Stagg’s argument that June 5 wasn’t the best day to invade was mixed.
Stagg and his crew extrapolated data from weather stations around the UK and the Atlantic without any modern meteorologists’ tools to determine the ideal time for the invasion.
The group at Bletchley Park that deciphered the Enigma codes allowed them to exploit information that the German U-boats were transmitting.
Although they would still be up against the elements, strong winds and rough seas, Stagg proposed that attacking on June 6 would have a better chance of success. (Source: History)
How Many Boats Landed on D-Day?
The logistics required to execute the Normandy landing were enormous. Everything was carefully planned, right down to how they would transport the men to the shore while dodging the German defenses’ heavy gunfire and artillery.
The famous landing boats were built to traverse the American swamps of Louisiana. Because they could pull right up onto the beach, they gave their passengers the best chance of landing. Until landfall, the vehicle’s ramp functioned as a shield to keep the soldiers safe. But as soon as the ramp was down, the soldiers inside became easy prey.
Approximately 6,939 ships, boats, landing vessels, 2,395 aircraft, and 867 gliders were mobilized to maneuver the troops. (Source: History)
Did Germany Know About D-Day Ahead of Time?
The French Resistance’s action did very little to alleviate this doubt. The French Resistance was inspired to action after hearing a poem read over an allied radio channel and learning about the invasion. Numerous acts of sabotage, such as the destruction of train infrastructure and the severing of phone connections, were committed throughout France.
When the Germans heard the poem, they concluded it was a coded message intended for resistance fighters but didn’t think it was a direct order. They vastly miscalculated the magnitude and speed of the impending ground sabotage.
The German high command first disregarded the invasion news when it arrived. The fact that report could not go rapidly up the coast due to the sabotage activities meant that by the time they took the information seriously, it was too late. They believed it to be an attempt at misdirection by the Allies before the “real” invasion farther north.
While the information took some time to reach Hitler, it traveled quickly throughout occupied Europe. In her diary, Anne Frank writes about the day they learned about D-Day and expresses the hope that it won’t be long before she and her family are freed from the annex. Sadly, the Nazis found Anne and her family before the Allies could reach them. (Source: History)
Image from Time.com