The large snowfalls last week brought magnificent conditions across the Alps, Pyrenees and Scandinavia.

The snow in many areas is already more than twice as deep as average for this time of year. The high-altitude resort of Zermatt in Switzerland has reported more than 2m of snow, but even slopes down to 1,000m (3,280ft) have had enough snow to leave sufficient cover for the rest of December without another snowflake falling.

Particularly encouraging is that the big snowfalls have come with very cold weather. Often an early snowfall quickly melts because the ground is too warm. The recent cold temperatures froze the ground, however, letting the snow settle and build up a thick base, which can better withstand a run of no snow during the rest of the season.

Scotland's resorts have also benefited from the bonanza. Visitor numbers had dropped alarmingly in recent years as winters have grown milder and shorter.

The autumn snowfalls in Europe have been delivered on northerly airflows streaming down from the Arctic. The winds are being driven by two big pressure systems in the mid-Atlantic, known as the North Atlantic Oscillation. As low pressure around Iceland and high pressure over the Azores slacken, so cold, wet air is steered over Western Europe, producing snow over mountains from northern Spain to Scandinavia. This type of pattern produced some brutal winters in the 1960s and 1970s. Since then the North Atlantic Oscillation has tended to intensify, driving milder winter weather over northwestern Europe.

This year's early taste of winter does not necessarily mean that it will last, but the weather pattern looks as if it is locked in place well into December, with the promise of more cold and snow to come for Europe. A particularly striking feature of this pattern is the way the Azores high pressure is stuck in the mid-Atlantic, held in place by a big kink in the high-altitude jet stream winds like a pair of nutcrackers. This is known as a blocking weather pattern, and tends to last for some time, and until it shifts the weather is likely to remain much the same.

However, the Met Office reiterated its long-range forecast for a milder than average winter over northern Europe. If last winter is anything to go by, though, the European mountains may stay cold while lowland areas enjoy relatively milder conditions.