Two of the three forecasts for June 6 had ideal foggy conditions for a surprise invasion on the beaches of Normandy. One forecast had a clear morning, which could have spelled disaster for the allies. President Dwight D. Eisenhower intuitively recognized there was uncertainty and knowingly played the odds, fortunately winning the day. To the extent that this three-member ensemble reliably estimated the odds, there indeed was a 33.3 percent chance D-Day might have been a disaster for the landing forces. There rarely is a perfect forecast when looking at the weather models. It is an inexact science.