Rain and snow mixed and snow. Though no "official" criteria exist for the term, in the United Kingdom the term is not used when any significant accumulation of snow on the ground takes place. It is often used when the temperature of the ground surface is above , preventing accumulation from occurring even if the air temperature is marginally below ; but even then, the falling precipitation must generally be something other than exclusively snow. In the United States, wintry mix generally refers to a mixture of freezing rain, ice pellets, and snow. In contrast to the usage in the United Kingdom, in the
2005 United Kingdom snow events North Yorkshire received 20 cm of snow over high ground, whilst the snow caused huge tailbacks on the A1 between Alnwick and Berwick. The snow showers petered later on the 29th as outbreaks of rain, sleet and hill snow moved into western areas. On Friday 30 December, a band of heavy rain pushed eastwards, with heavy snow on the leading edge. This brought several hours of snow followed by rain, where 20 cm fell in some parts of Yorkshire, with snowdrifts of 1 metre reported. The snow caused hundreds of drivers to be stranded on the A1079 during the late