
A significant event in weather history surrounds the planning of a major invasion by the Allied Forces. D-Day is still remembered as one of the biggest invasions and one that relied on certain weather conditions.
On June 3, 1944, Dr. James Stagg of the British Meteorological Office briefed General Dwight Eisenhower and his commanders. Based on the weather forecasts, the departure planned for June 5 appeared to be impossible.
The English Channel was dealing with its worst weather conditions in decades and unsettled conditions were too much for air support. A Royal Navy ship then reported sustained rising pressure in its area, which would allow a narrow and unexpected window of opportunity for June 6.
The Germans were completely caught off guard with their airplanes grounded and naval vessels absent.
If the forecast did not hold, the Allies would have had to wait two more weeks to carry out in the invasion, which could have been catastrophic to the outcome of the mission.
A brief and barely tolerable break in the weather conditions allowed the long-planned invasion, one that changed the course of World War II, to become a reality.