D-Day is remembered as an incredible military operation. Pictures and videos show troops on the ground, in the water and in the air.
But weather forecasters also played a big role in the historic attack.
This week is the 75th anniversary of D-Day — the day allied forces invaded France via Normandy. It was originally planned for June 5th due to optimal conditions for astronomical reasons. But it was pushed back because of the weather.
On June 4th, 1944 the weather was not good. The strong winds, bad seas, and low clouds were expected to last through the 5th. Geophysicist and Captain James Stagg and his team made a forecast that suggested to President Eisenhower that the weather would clear June 6th.
This forecast was made in the early days of forecasting, long before satellites, telecommunications, or computers. In fact, the forecasting technique that was used was even considered new. So to go with a 2-day forecast in the 1940s is about the same as trusting a 7 or 8 day forecast today.
The concern in the forecast was a couple rounds of storms and fronts.
But, President Eisenhower took Stagg’s advice and pushed the invasion back one day, which gave the allied forces the advantage for the surprise attack and the rest is history.