Analysis: Record blast for winter as jet stream interacts with Atlantic lows

THE UK, and Scotland in particular, has seen some very stormy conditions since this winter started at the beginning of December. This has been caused by a succession of deep, low pressure systems coming in from the Atlantic, bringing extremely strong winds.

A gust of 165mph was recorded at Cairn Gorm summit (4,082ft, or 1,244m) during the first of the winter storms on 8 December – that was just 8mph off the strongest ever recorded gust for the UK, which was set at the same spot in 1986.

The Met Office has put out numerous severe weather warnings during this time, including two red warnings – the most severe level possible – for Scotland in the past month. Normally, we would expect to put out about two red warnings for the full year.

So why has it been so stormy this winter? The blame lies with a “mobile weather pattern”. This is a general westerly flow over the UK which allows Atlantic low pressure systems to track over the UK unimpeded. This is normal for this time of year and the weather, in general terms, is also in line with what we would expect for a UK winter.

However, the storms and wind speeds we have been particularly strong. This is down to the jet stream – the high altitude winds which blow from east to west across the Atlantic and brings us our traditional changeable weather. Its path and strength changes on a regular basis and this can have an impact on weather over the UK. Over the past few weeks the jet stream has occasionally been particularly strong and some of the low pressure systems have interacted with that as they have tracked over the Atlantic, boosting their strength. This has led some of the lows to develop into powerful storms with very strong winds.

• Dan Williams is a spokesman for the Met Office.