There seems to be no end in sight to the big freeze. Yesterday much of the country was buried in deep snow. Today it is the turn of southern and eastern England — again.

The Met Office expects anything up to 5cm (2in) in London and possibly 20cm (8in) on higher ground, such as the Chilterns, with the potential to cause more chaos on road and rail and at airports.

This weather pattern is stuck in a rut, going round and round like a carousel in a never-ending scene reminiscent of the film Groundhog Day — the American holiday that, ironically, was on Monday. The prediction this year was six more weeks of winter after a groundhog crawled out of his burrow and cast a shadow.

The depression that dumped so much snow throughout this week has been wheeling slowly around Britain and the Bay of Biscay. As it heads north up the English Channel, it turns into a loaded gun, charged up with mild, wet air. When that hits much colder air streaming down from Northern Europe, the slab of moist, warm air explodes into snow showers. Because the depression is moving so slowly it has plenty of time to bring significant snowfalls.

Today's snows will not be as spectacular as Monday's, which were beefed up by warmth scooped up over the North Sea, and which also set off some spectacular outbursts of thunder and lightning.

The weather pattern is stuck, thanks partly to a big kink in the jet stream. These high-altitude winds have been charging across the Atlantic at about 200mph (320km/h) but dived south of Britain into the Mediterranean, blasting Southern Europe and North Africa with wet and windy weather. That has left Britain facing the full brunt of bitterly cold Arctic air, which will continue streaming down through the weekend and into next week.

Although the weekend will be much calmer, except for northern Scotland, the forecasters are watching with some trepidation as another depression may develop in the Bay of Biscay at the start of next week, threatening a repeat performance of this week's snowstorms.

Predicting snowfalls is one of the most difficult jobs for a British forecaster. Often the forecast balances on a knife edge, as the air close to the ground can turn just warm enough to melt any falling snow, and when the temperature is close to freezing it can turn to rain, sleet, snow or hail. Trying to figure out exactly where that precipitation will fall is another fine judgment.

So it seems particularly unfair that the local authorities have been hit by an avalanche of criticism for running out of stocks of salt and grit for the roads. Back in October the long-range winter forecast was for average, or slightly below average, temperatures, with the season to end in much milder weather. In other words, it was thought that February would be more like spring, based partly on a cooling of the tropical seas in the Pacific, called La Niña. However, at the end of January the stratosphere flipped unexpectedly, sending bitterly cold easterly winds racing over Britain and drowning out the influence of the anticipated warm spell.

Let's look on the bright side. This week's weather has been a fantastic boost for the Scottish ski resorts, currently enjoying some of their best snows in years, with Cairngorm reporting up to 2ft (60cm) of fresh snow.