Worst Blow in 40 Years
Had Stagg and the disparate meteorologists at the Admiralty, Dunstable, and Widewing not foreseen the break in the weather for the night of 5/6 June, the invasion fleet would have had to return to port to refuel and reorganize. D-day would have been postponed to 19 June, the next period of low Normandy tide at dawn.
A decisive forecast for that date would have had to be made no later than early morning on June 18. On the 17th, the weather had looked ideal. A ridge of high pressure was sprawling across all of England. But the picture turned on a dime. A cold front passing through Iceland broke southeastward and began speeding through the British Isles. A steep ridge of high pressure followed it. At the same time, a low was spreading over France from the Mediterranean. Between the two systems the pressure gradient would be very sharp. Near gale force winds would howl down the Channel from the northeast toward the invasion beaches. Low scudding cloud would blanket Normandy.
Immediately after D-day, the Mulberry artificial harbors off the fishing village of Arromanches on Gold Beach and a second one at Omaha Beach were installed. By 18 June, 197,444 troops, 27,340 vehicles, and 68,799 long tons (a British long ton equals 2,240 pounds) of supplies had crossed the causeways from newly emplaced docks onto dry land at Omaha.
However, at midnight 18-19 June, the weather turned violent. For the next four days winds gusting up to 37 mph pushed waves of eight feet or more, which tore at the pieced-together harbor. LCTs and LCVPs without enough power to turn and ride out the storm slammed into the docks. On 20-21 June 20, the cacophony of screaming wind and the roar of driving rain was punctuated by the thunder of surf and the crash of grounding landing craft, DUKS, and their cargoes and by the grinding wreckage of disintegrating Mulberry harbors.
But Admiral Ramsay, Admiral (John L.) Hall, and Army Engineers’ reports agree that all weather forecasts received by them were for that period favorable. Imagine if this storm had happened on D-day. No wonder Eisenhower penciled on the corner of his commendation letter to Stagg: “I thank the gods of war we went when we did.”