The North Atlantic weather war occurred during World War II . The Allies (Britain in particular) and Germany tried to gain a monopoly on weather data in the North Atlantic and Arctic oceans. Meteorological intelligence was important as it affected military planning and the routing of ships and convoys. In some circumstances, visibility was necessary (photographic reconnaissance and bombing raids) and in others concealment (keeping ship movements secret or suppressing enemy air activity). D-day planning was greatly affected by weather forecasting ; it was delayed by one day in the expectation that a storm would blow out and sea conditions would be acceptable. British sources of data included ships at sea and the weather stations at Valentia Observatory and Blacksod Point , in neutral Ireland ; German use of weather ships also exposed their secret Enigma codes.
31-785: Group Captain James Martin Stagg , CB , OBE , FRSE (30 June 1900 – 23 June 1975) was a British Met Office meteorologist attached to the Royal Air Force during the Second World War who notably persuaded General Dwight D. Eisenhower to change the date of the Allied invasion of Europe from 5 to 6 June 1944. Stagg was born on 30 June 1900 in Musselburgh , East Lothian , Scotland, to Alexander C. Stagg and his wife, Helen (Ellen). He
62-561: Is in the accounts published by participants, including Stagg himself. Planners of the Normandy landings in June 1944 allowed for the tides, the time of day, and the phase of the moon – these conditions would be satisfactory on only a few days in each month. A full moon was desirable, as it would provide illumination for aircraft pilots and have the highest tides . The landings would be shortly before dawn, mid-way between low and high tide, with
93-680: The Luftwaffe meteorological centre in Paris was predicting two weeks of stormy weather, many Wehrmacht commanders left their posts to attend war games in Rennes , and men in many units were given leave. German Commander Field Marshal Erwin Rommel returned to Germany for his wife's birthday and to meet with Hitler to try to obtain more Panzers . For his invaluable services over the D-Day period, Stagg
124-580: The Royal Air Force . The rank is used by air forces of many countries that have historical British influence . Group captain is immediately senior to wing commander and immediately below air commodore . It is usually equivalent to the rank of captain in the navy and of the rank of colonel in other services. The equivalent rank in the Women's Auxiliary Air Force , Women's Auxiliary Australian Air Force , Women's Royal Air Force (until 1968) and Princess Mary's Royal Air Force Nursing Service (until 1980)
155-560: The 2004 TV movie Ike: Countdown to D-Day , David Haig in his own 2014 play Pressure , and Steven Cree in 2017's Churchill . In 1940, Stagg married Elizabeth Nancy Kidner. They had two sons: Scotland rugby player Peter Stagg (born 1941); and Alexander Martin Stagg (born 1944). Pressure by David Haig (2014) Group Captain Group captain ( Gp Capt or G/C ) is a senior officer rank used by some air forces, with origins from
186-698: The Allies could follow the progress of a front as it traveled across the Atlantic. The Germans, with their small number of (impermanent) observation stations, had to rely on a certain amount of luck to detect a weather front before it reached Europe. In August 1941, in the preparation for Operation Gauntlet (the occupation of Spitsbergen), the Royal Navy destroyed the weather station on Bear Island and later, one on Spitsbergen (after it had transmitted false information to discourage air observation). Spitsbergen
217-722: The British Polar Expedition of Arctic Canada. In 1936, he received a Doctor of Science (DSc) degree from the University of Edinburgh for a collection of papers on terrestrial magnetism . In the 1937 Coronation Honours , he was appointed Officer of the Order of the British Empire (OBE) for his work as a senior technical officer with the Air Ministry 's Meteorological Office. Stagg was appointed
248-695: The Chief Meteorological Officer, SHAEF for Operation Overlord . On 6 November 1943, he was granted an emergency commission with the rank of group captain in the Royal Air Force Volunteer Reserve ; this leant him the necessary authority in a military milieu unused to outsiders. Stagg worked with three forecasting teams from the Royal Navy , Met Office and the USAAF . The detail of the D-Day forecasts
279-749: The German weather ships, to help Bletchley Park to resume their cryptanalysis of the Enigma Navy version, as the inability to decode the new M4 "shark" cypher was seriously affecting the Battle of the Atlantic . Munchen and Lauenburg were boarded by the Royal Navy , who managed to gather valuable information on German codes in each case. Wuppertal became trapped in ice and was lost without trace of ship or crew. The Germans made attempts to set up land-based weather stations in contested locations such as Spitsbergen and even on Allied-held shores, such as
310-611: The RAF might base many of its officer rank titles on naval officer ranks with differing pre-modifying terms. It was also suggested that RAF colonels might be entitled "bannerets" or "leaders". However, the rank title based on the Navy rank was preferred and as RAF colonels typically commanded groups the rank title group captain was chosen. The rank of group captain was introduced in August 1919 and has been used continuously since then. Although in
341-457: The RAF. In response to the proposal that the RAF should use its own rank titles, it was suggested that the RAF might use the Royal Navy 's officer ranks, with the word "air" inserted before the naval rank title. For example, the rank that later became group captain would have been "air captain". Although the Admiralty objected to this simple modification of their rank titles, it was agreed that
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#1732773172466372-572: The assignment. They used surface weather observations , radiosondes and pilot balloons (PIBALs) to determine weather conditions aloft. Due to its value, operations continued after World War II, leading to an international agreement in September 1946 that no fewer than 13 ocean weather stations would be maintained by the Coast Guard, with five others maintained by Great Britain and two by Brazil . The Germans began to use weather ships in
403-596: The automated Weather Station Kurt in Labrador . The Germans were obliged, by their continental location, to rely largely on long-range aircraft and weather ships—which were vulnerable to attack—and on clandestine stations in exposed locations. The Allies had a distinct advantage in the contest, controlling all of the major islands (Newfoundland, Greenland, Iceland, Great Britain) of the North Atlantic. As weather patterns at that latitude generally travel west to east,
434-542: The chance that the invasion plans would be detected. After much discussion with the other senior commanders, Eisenhower decided that the invasion should go ahead on the 6th. A major storm battered the Normandy coast from 19 to 22 June, which would have made the beach landings impossible. Allied control of the Atlantic gave Allied meteorologists an advantage in the North Atlantic weather war for storm prediction. As
465-513: The deployment of two more weather ships in 1943 and 1944. The United Kingdom established one 80 km (50 mi) off the west coast of Britain. By May 1945, sixteen ships were in use north of the 15th parallel north in the Atlantic, with six more in the tropical Atlantic. Twenty United States Navy frigates were used in the Pacific for similar operations. Weather Bureau personnel stationed on weather ships were asked voluntarily to accept
496-407: The early years of the RAF groups were normally commanded by group captains, by the mid-1920s they were usually commanded by an air officer . In the post-World War II period the commander of an RAF flying station or a major ground training station has typically been a group captain. More recently, expeditionary air wings have also been commanded by group captains. The rank insignia is based on
527-479: The evening of 4 June. He and his meteorological team predicted that the weather would improve enough for the invasion to proceed on 6 June. The next available dates with the required tidal conditions (but without the desirable full moon) would be two weeks later, from 18 to 20 June. Postponement of the invasion would have required recalling men and ships already in position to cross the Channel, and would have increased
558-490: The former cargo ships had top speeds of 10-12 knots, significantly less than U-Boats, which could reach 16 knots on the surface. USCGC Muskeget was torpedoed with 121 aboard on September 9, 1942. In 1943, the United States Weather Bureau recognized their observations as "indispensable" for the war effort. The flying of fighter aircraft between North America , Greenland and Iceland led to
589-402: The four gold bands of captains in the Royal Navy, comprising four narrow light blue bands over slightly wider black bands. This is worn on both the lower sleeves of the tunic or on the shoulders of the flying suit or the casual uniform. Group captains are the first rank in the RAF hierarchy to wear gold braid on the peak of their cap, informally known as ' scrambled egg '; however, they still wear
620-881: The manned Schatzgräber station on Alexandra Land in the Soviet Franz Josef Land archipelago from November 1943 to July 1944. The RAF operated 518 Squadron from RAF Tiree in the Scottish Hebrides , 519 Squadron from RAF Wick and RAF Skitten in Caithness , Scotland and 517 Squadron from RAF Brawdy , in south-west Wales, to fly meteorological sorties into the Atlantic. Flying standard patrol patterns, Handley Page Halifaxes , Lockheed Hudsons and Boeing B-17 Flying Fortresses and other aircraft made meteorological readings at various heights from 50 ft (15 m) to their ceiling of 18,000 ft (5,500 m), at prescribed points along
651-476: The patrols. The patrols were long (up to 11 + 1 ⁄ 2 hours); in often poor weather and sometimes dangerous, at least ten aircraft from 518 Squadron were lost with all hands during 1944. Meteorological reports from air patrols influenced the timing of D-Day. The critical patrol experienced severe weather conditions and its crew's reports were so extreme that they were not to be believed at first. A similar patrol from Brawdy reported similarly bad conditions but
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#1732773172466682-458: The standard RAF officer's cap badge. The command pennant for a group captain is similar to the one for a wing commander except that there is one broad red band in the centre. Only the wing commander and group captain command pennants are triangular in shape. North Atlantic weather war In 1939, United States Coast Guard vessels were being used as weather ships to protect transatlantic air commerce. The Atlantic Weather Observation Service
713-570: The summer of 1940 but three of its four ships were sunk by November 23, which led to the use of fishing vessels for its weather ship fleet. German weather ships were out to sea for three to five weeks at a time and would have Enigma machine and codes for several months to send weather observations in cypher. Their radio reports exposed their location to the superior British High-frequency direction finding system and their encryption provided additional fodder for British cryptanalysts. Harry Hinsley worked on plans to seize Enigma machines and keys from
744-450: The tide coming in. This would improve the visibility of obstacles on the beach, while minimising the amount of time the men would be exposed in the open. Eisenhower had tentatively selected 5 June as the date for the assault. However, on 4 June, conditions were unsuitable for a landing: high winds and heavy seas made it impossible to launch landing craft, and low clouds would prevent aircraft from finding their targets. Stagg met Eisenhower on
775-692: Was "group officer". The rank was used in the Royal Canadian Air Force until the 1968 unification of the Canadian Forces , when army-type rank titles were adopted. Canadian group captains then became colonels . In official Canadian French usage, the rank title was colonel d'aviation . On 1 April 1918, the newly created RAF adopted its officer rank titles from the British Army , with Royal Naval Air Service captains and Royal Flying Corps colonels becoming colonels in
806-712: Was an important location: it enabled the Germans to monitor weather conditions on the Allied convoy route to northern Russia . The Germans made several attempts to establish and maintain weather stations in the Svalbard archipelago including Spitsbergen and Hopen (Hope Island: stations Svartisen and Helhus) and these were never suppressed. Other locations used included those on Jan Mayen Island , Bear Island ( Taaget [ de ] , 1944–1945) and eastern Greenland with teams and automated stations. The Kriegsmarine operated
837-722: Was appointed an Officer of the US Legion of Merit in October 1945. Stagg later worked as director of services at the Meteorological Office until 1960. Stagg was appointed Companion of the Order of the Bath (CB) in the 1954 New Year Honours . He was elected as a Fellow of the Royal Society of Edinburgh in 1951. His proposers were Edmund Dymond , James Paton, C. T. R. Wilson and Robert Schlapp . In 1959 he
868-568: Was authorized by President Franklin Delano Roosevelt on January 25, 1940. By February 1941, five 327 ft (100 m) Coast Guard cutters were used in weather patrol, usually deployed for three weeks at a time, then sent back to port for ten days. As World War II continued, cutters were needed for the war effort and by August 1942, six cargo vessels were used. The ships were modified with guns and depth charge projectors , and crews were trained and regularly drilled in gunnery but
899-722: Was commissioned as a second lieutenant in the Officers' Training Corps (OTC), to serve with the George Heriot's School contingent of the junior division of the OTC (the equivalent of what is now the Combined Cadet Force ). In 1924 Stagg became an assistant in the British Meteorological Office and he was appointed superintendent of Kew Observatory in 1939. In the winter of 1932/33 he led
930-606: Was educated at Dalkeith High School in Dalkeith until the age of 15. As Dalkeith High did not provide further education , he completed his schooling at Broughton Junior Student Centre in Edinburgh . In 1921, Stagg graduated with an undergraduate Master of Arts (MA Hons) from the University of Edinburgh . He then became a teacher and worked as science master at George Heriot's School in Edinburgh . On 7 April 1923, he
961-569: Was elected President of the Royal Meteorological Society . Stagg died in 1975 and was buried in Dalkeith Cemetery. On 6 June 2019, 75 years to the day since D-Day, he had a plaque unveiled to him in his hometown of Dalkeith. Achieved through crowdfunding , the plaque was unveiled by his son, Peter Stagg . Stagg was portrayed by Patrick Barr in the 1962 film The Longest Day , Christopher James Baker in