Weather for Overlord
The sequence of weather events surrounding Operation Overlord is one of the most miraculous stories of World War II. The D-Day invasion was vastly complex and had many meteorological requirements. A low tide at first light was needed to expose beach obstacles to the assault waves. A full moon after midnight the night before was necessary for airborne operations. June 5 and 6 came closest to meeting these conditions.
Additionally, however, the winds could not be too strong for landing craft and paratroopers. The clouds could not be too low for aircraft. Surf conditions had to be acceptable. The chief meteorologist estimated the odds of all these requirements being met in early summer on the coast of France as fifty or sixty to one.453 On Jun…stormy English Channel seemed to bear out these odds. D-Day on the 5th had to be canceled.
From the German perspective, May seemed a more likely month for the invasion. During periods of good weather in May, coastal defense forces were put on maximum alert. When the weather turned bad in early June, readiness was relaxed and some units were withdrawn from the coast for exercises inland. Conditions were so bad that reconnaissance aircraft could not fly. General Rommel felt that action was so unlikely that he left his headquarters for a visit to Germany.
With ships at sea and all of his forces poised to go, General Eisenhower and his staff agonized over each weather report. A slim chance for a break on June 6 was forecast. The moon and tides would not be right again until June 1920. On this slim hope, Ike finally announced, “OK. We’ll go.”454 The weather was not perfect. It was just bad enough to lull the German defenders and just good enough to allow the essential Allied landing operations to proceed successfully.
When gale force winds struck the Normandy coast on June 1920, General Eisenhower sent his chief meteorologist a note saying how thankful he was that they went when they did. He would not have had a second chance. Thanks to this miraculous weather pattern, the greatest invasion in history succeeded.
Then the Lord sent a great wind on the sea, and such a violent storm arose that the ship threatened to break up.
—Jonah 1:4