For much of the country it was a cloudy night and although largely dry across many southern and western counties of England, a few showers affected many central and eastern districts of both Scotland and England. An area of more organised rain affected western parts of Scotland and northwest England. Most places dawned cloudy with continuing showers across northern and eastern districts. Southern Britain dawned dry and across southwest England there were a few breaks to allow some bright or sunny spells to develop. The morning saw the rain band across north-western districts slowly pushed south into other parts of northwest England and the Midlands. Showers continued to affect eastern counties and these became more widespread across Scotland. For the rest of the country, including Wales, central southern and southwest England it remained dry with sunny intervals and patchy cloud, the best of the sunshine was across Devon and Cornwall and parts of South Wales. The afternoon saw little general change with showers continuing to affect much of Scotland, northern and eastern England whereas many southern and south-western counties remained dry with variable amounts of cloud. It was a windy day with moderate to fresh north-westerly winds across the country, the wind only slowly moderating during the afternoon. It was a co http://www.metoffice.gov.uk/media/pdf/d/6/D-Day_-_6_June_1944.pdf http://www.wrma.org/2009_euro_pres/MeteorologyandD-Day6June1944.pdf ECMWF Reanalysis and Forecasts of D-Day Weather
The 1944 surface pressure map and the 2017 version for 6th June. http://www.metoffice.gov.uk/binaries/content/assets/mohippo/pdf/1/6/mo_06061944_13_utc.pdf Surface pressure charts - Met Office
Charts in the Met Office National Meteorological Archive in Exeter reveal that the allies had cracked the German Enigma code thus allowing the D-Day forecasters access not only to observations from Allied observers and reconnaissance flights but also to all the German meteorological observations. Comparison of the synoptic charts held in the Met Office archives and the archives of Deutscher Wetterdienst clearly shows this placed the Allied forecasters at a significant advantage over the German forecasters in terms of being able to spot a suitable weather window for the invasion. The allied charts contain a wealth of observations from across both the UK and Europe and also some observations from the Atlantic, the area from with the D-Day weather would come. By contrast the German charts reveal that they had been unable to crack the Allied codes and as a result there are virtually no observations for the UK and surrounding waters. Having access to this additional data gave the allied forecasters sufficient information to be able to plot the location and movement of the low pressure and cold front which forced the landings to be moved from the 5th to the 6th, and the ridge of high pressure which enabled them to predict better weather for the 6th with far greater accuracy than their German counterparts. As a result Stagg was able to advise that conditions on the 6th June would be marginal but sufficient to launch the invasion and in so doing the D-Day forecasters made perhaps the most important forecast in history. D-Day and Operation Overlord
Weather information relating to D-Day and Operation Overlord In spite of meticulous planning surrounding all other aspects of the invasion the commanders could not control the weather and for advice on this they looked to a team of meteorologists led by Group Captain J. M. Stagg from the Met Office. Conditions in early June were extremely unsettled and the forecasters on both sides needed all the information they could get in order to predict when the invasion might occur. Stagg and his teams relied on the synoptic charts to provide the information they needed. These charts identified both the bad weather which resulted in the postponement of the invasion on the 5th and identified the weather window which enabled it to go ahead on the 6th. Charts in the Met Office National Meteorological Archive in Exeter reveal that the allies had cracked the German Enigma code thus allowing the D-Day forecasters access not only to observations from Allied observers and reconnaissance flights but also to all the German meteorological observations. Comparison of the synoptic charts held in the Met Office archives and the archives of Deutscher Wetterdienst clearly shows this placed the Allied forecasters at a significant advantage over the German forecasters in terms of being able to spot a suitable weather window for the invasion. The allied charts contain a wealth of observations from across both the UK and Europe and also some observations from the Atlantic, the area from with the D-Day weather would come. By contrast the German charts reveal that they had been unable to crack the Allied codes and as a result there are virtually no observations for the UK and surrounding waters. Having access to this additional data gave the allied forecasters sufficient information to be able to plot the location and movement of the low pressure and cold front which forced the landings to be moved from the 5th to the 6th, and the ridge of high pressure which enabled them to predict better weather for the 6th with far greater accuracy than their German counterparts. As a result Stagg was able to advise that conditions on the 6th June would be marginal but sufficient to launch the invasion and in so doing the D-Day forecasters made perhaps the most important forecast in history. D-Day and Operation Overlord - Met Office
Group Captain James Martin Stagg, CB, OBE, FRSE (30 June 1900 – 23 June 1975) was a British Royal Air Forcemeteorologist 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. James Stagg - Wikipedia
