<P> Tropical cyclones themselves do not affect the UK due to the seas being too cold--they need temperatures above 26.5 ° C (79.7 ° F) to remain active . The waters near the UK, the Atlantic Ocean, only have temperatures of 2 to 18 ° C (36 to 64 ° F), so any tropical cyclone that does come anywhere near the UK has said to have undergone a process called extratropical transition . This now means it is an extratropical cyclone, which the UK frequently experiences . The Great Storm of 1987 was a very deep depression which formed in the Bay of Biscay, which also contained the remnants of Hurricane Floyd . Hurricane Lili of 1996 and Hurricane Gordon of 2006 both crossed the UK as strong extratropical cyclones with tropical storm - force winds, causing transport closures, power - cuts and flooding in Northern Ireland, Scotland and South West England . In 2011, the remnants of Hurricane Katia passed over northwestern Scotland with winds near 70 mph (110 km / h). </P> <P> It is internationally recognised that the United Kingdom has a higher incidence of tornadoes, measured by unit area of land, than any other country in the world . Dr T. Theodore Fujita (inventor of the Fujita scale), an American meteorologist, was the first to recognise the UK as the top site for tornadoes in 1973 . The United Kingdom has at least 33 tornadoes per year, more than any other country in the world relative to its land area . Although most tornadoes are weak, there are occasional destructive events, for example, the Birmingham tornado of 2005 and the London tornado of 2006 . Both registered F2 on the Fujita scale and both caused significant damage and injury . The largest ever recorded was thought to have been an F4, again in London in 1091 . The most deadly occurred on 28 December 1879 . All 74 lives were lost when a passenger train plunged from the Tay Bridge (Tayside) into the Tay Estuary, when the middle section of the bridge collapsed . Although the bridge was poorly constructed and had already been weakened in earlier gales (including the pre-existing winds at the time of the tragedy), the ultimate failure is believed to have been caused by two or three waterspouts which were sighted close to the bridge immediately before the accident . A tornado also developed in London on 3 July 2007 . </P> <P> The UK also holds the title for the highest known' outbreak' of tornadoes outside of the United States . The largest tornado outbreak in Britain is also the largest tornado outbreak known anywhere in Europe . On 23 November 1981, 105 tornadoes were spawned by a cold front in the space of 5.25 hours . Excepting Derbyshire, every county in a triangular area from Gwynedd to Humberside to Essex was hit by at least one tornado, while Norfolk was hit by at least 13 . Very fortunately most tornadoes were short - lived and also weak (the strongest was around T5 on the TORRO Tornado Scale) and no deaths occurred . </P> <P> The climate of the United Kingdom has not always been the way it is today . During some periods it was much warmer and in others it was much colder . The last glacial period was a period of extreme cold weather that lasted for tens of thousands of years and ended about 10,000 years ago . During this period the temperature was so low that much of the surrounding ocean froze and a great ice sheet extended over all of the United Kingdom except the south of England (connected to mainland Europe via the dry English Channel) and southern coastal areas of Wales . </P>

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