European winter storms of 2009–2010

Winter of 2009–2010 in Europe

Map of Europe showing the difference of temperature between 11–18 December 2009 and the 2000–2008 average.
Type	Winter storm
Formed	16 December 2009
Lowest temperature	−45.6 °C (−50.1 °F) in Folldal, Norway
Maximum snowfall or ice accretion	115 centimetres (45 in) on 25 February in Kvam, Norway
Total fatalities	> 310
Areas affected	Most of Europe

The winter of 2009–2010 in Europe was unusually cold. Globally, unusual weather patterns brought cold, moist air from the north. Weather systems were undergoing cyclogenesis from North American storms moving across the Atlantic Ocean to the west, and saw many parts of Europe experiencing heavy snowfall and record-low temperatures. This led to a number of deaths, widespread transport disruption, power failures and postponed sporting events.

The cold weather was caused by high pressure over Greenland and Iceland forcing weather patterns southward, a phenomenon described by meteorologists as the Arctic Oscillation and also the North Atlantic Oscillation which were negative compared to normal. The North Atlantic Oscillation in Winter 2009/10 was lower than during any winter in over a century and this resulted in more easterly winds bringing cold air into Northern Europe from Siberia and the Arctic. Scientists have shown that El Niño, the Quasi-Biennial Oscillation and solar variability all conspired to drive this extreme winter.

Light snowfall occurred in the UK on 16 December and weather warnings were given on most local TV stations; there were some traffic jams towards the south. The snow later spread towards France and northern Spain. In mainland Europe, early snowfall was seen across much of the western half of the continent. On 17 December, the Swiss canton of Grisons saw a record-low overnight temperature of −32 °C (−25.6 °F). This snowfall led to the shutdown of Utrecht Centraal (the largest rail hub in the Netherlands). While snowfall on highways led to the busiest morning rush hour of 2009, with a total of 671 km (417 m) in traffic jams. The following day, heavy overnight snowfall caused widespread disruption across large parts of the South East, East Anglia, the East Midlands and Yorkshire and the Humber in Britain. This snow was in the north half of a depression with east winds centred south of England. Several deaths attributed to the cold weather were reported.