Where did the snowfall come from?

It has been the UK’s biggest and most widespread snowfall for 18 years, but where did it come from?

 The UK sits between a huge ocean to the north and west (the Atlantic), and a large continent to the south and east (Europe).

As a rule, the Atlantic normally brings us mild and wet weather, something we have experienced over recent winters. In contrast, the east brings us the colder weather  we have been having this winter.

Jet stream

Why is that air from the east colder? Because land cools quicker than the sea. Conversely, it means that in the summer the same eastern weather front will bring us warmer weather.

Our weather is also strongly influenced by the jet stream, a fast moving stream of air at 30,000ft that pushes weather systems around the world. It normally brings mild Atlantic weather across the UK.

However, this winter, the jet stream has not been blowing over the UK.  Without it the cold weather has been free to move in from the east.

Snowfall from Russia

According to the Met Office, this week’s severe weather developed as a cold mass of air that moved across Europe from Russia. As it passed over the North Sea it picked up moisture that led to the heavy snowfall, firstly in eastern England on Sunday morning and soon after, the rest of the UK.

Later on Monday a second patch of heavy snow moved across England from France. The double impact led to some of the heaviest snowfall seen in Britain since February 1991, with depths of 31cm or 12 inches recorded in Epsom, Surrey.

This movement of cold weather from eastern Europe in addition to some bitterly cold conditions from the arctic continued during the week bringing more snowfall to parts of the UK and Ireland.