James Stagg
Group Captain James Martin Stagg, CB, OBE, FRSE was a British Royal Air Force meteorologist who notably persuaded General Dwight D. Eisenhower to change the date of the Allied invasion of Europe in World War II, from the 5th of June to the 6th of June 1944.
Stagg was born in Dalkeith, Scotland to Alexander and Ellen Stagg. In 1924, he became an assistant in the British Meteorological Office and was superintendent of the Kew Gardens observatory in 1939. In 1940, he married Elizabeth Nancy Kidner they had two sons, Scotland rugby player Peter Kidner Stagg and Alexander Martin Stagg . In 1943, he was commissioned a Group Captain in the Royal Air Force Volunteer Reserve and appointed the chief meteorological officer for Operation Overlord. Stagg was the senior staff meteorologist working with input from three separate forecasting teams from the Royal Navy, Met Office and USAAF. The detailed history of the forecasts is subject to disagreement in the accounts published by participants, including Stagg himself.
Source: Wikipedia