D-Day 5 June 1944

On 8 May General Eisenhower set D Day for Y plus 4, or 5 June.
General Eisenhower cabled General Marshall on Saturday, 3 June: "We have almost an even chance of having pretty fair conditions . . . only marked deterioration . . . would discourage our plans." But marked deterioration was already in the cards. That Saturday evening Group Captain Stagg again came before the Supreme Commander and his commanders in chief who were meeting at Southwick House north of Portsmouth, the headquarters of Admiral Ramsay. Group Captain Stagg had bad news.
Not only would the weather on 5 June be overcast and stormy with high winds and a cloud base of 500 feet to zero, but the weather was of such a nature that forecasting more than twenty-four hours in advance was highly undependable. The long period of settled conditions was breaking up. It was decided, after discussion, to postpone decision for seven hours and in the meantime let Force U and part of Force O sail on schedule for their rendezvous for the June D Day.
At 0430 Sunday morning a second meeting was held at which it was predicted that the sea conditions would be slightly better than anticipated but that overcast would still not permit use of the air force. Although General Montgomery then expressed his willingness to go ahead with the operation as scheduled, General Eisenhower decided to postpone it for twenty-four hours. He felt that OVERLORD was going in with a very slim margin of ground superiority and that only the Allied supremacy in the air made it a sound operation of war. If the air could not operate, the landings should not be risked. A prearranged signal was sent out to the invasion fleet, many of whose convoys were already at sea. The ships turned back and prepared to rendezvous twenty-four hours later.
On Sunday night, 4 June, at 2130 the high command met again in the library of Southwick House. Group Captain Stag reported a marked change in the weather. A rain front over the assault area was expected to clear in two or three hours and the clearing would last until Tuesday morning.