The Met Office has revealed why an icy blast could follow soaring temperatures this weekend
It might feel like spring has sprung, but the Met Office has warned that colder weather is on the way – thanks to a ‘rapidly weakening’ polar vortex.
Temperatures are set to be ‘well above the early-March average’ this weekend, the Met Office has said, after highs of 19C were recorded in Suffolk. The current forecast suggests highs of 18C could be seen in Manchester on Saturday and Sunday, which is warmer than in Barcelona (16C).
Despite forecasts suggesting the UK is set for the hottest day of the year so far, the Met Office warns that temperatures are about to plunge as some parts of Scotland could see temperatures as low as -4C on Tuesday (March 11). But what is driving this extreme shift in weather?
Deputy Chief Meteorologist at the Met Office, Chris Bulmer, said: “A frontal zone will move south across the UK during Sunday night and Monday with much colder air following from the north.
“With these cold northeasterly winds, we are likely to see some wintry showers across the north and the east of the UK next week, but any accumulations of snow are likely to be largely restricted to hills. We’ll also see a return to overnight frosts in many areas.
“While there is uncertainty in the extent of rain and wintry showers through the middle of next week, there is higher confidence that below average temperatures will continue through the week, bringing a very different feel to the mild weather over the weekend.”
However, the Met Office long range forecast suggests more icy weather could be on the horizon. The UK weather agency is forecasting a possible late cold snap thanks to a weather phenomenon called a ‘sudden stratospheric warming’. Such weather events are often associated with extreme snowfall, blizzards, and plummeting temperatures.
Sudden stratospheric warming (SSW) occurs when the stratosphere – the layer between 10 and 50km above Earth’s surface – heats up by 50 degrees in just two days. We don’t feel this ‘warming’ ourselves because it happens so high up, the Met Office says, but it can have an extreme knock-on effect on our weather.
Professor Adam Scaife, Head of Long-Range Forecasting at the Met Office, said: “There is now over 80 per cent chance of a SSW occurring by the middle of the month, this could lead to some impacts on weather in the UK toward the end of March. What those impacts might be will become clearer nearer the time.”
Earlier this week, the Met Office announced: “”The stratosphere polar vortex is now weakening rapidly.
“Over the last few days, the forecasts have become very confident and we are almost certain there will be a sudden stratospheric warming in mid-March. This is when the mid stratospheric wind is predicted to reverse from westerly to easterly.
“About 70 per cent of SSW events are followed by a change to cold conditions with easterly winds across northern Europe and the UK. There are now signs of this in the forecast and the risk of a cold snap later in March is increasing.”
Every winter, we see stronger winds in something called the polar vortex – a large, swirling area of low pressure and cold air around the Earth’s poles. Sometimes, this can temporarily weaken, or ‘collapse’, meaning cold air descends very rapidly. This then causes the stratosphere to warm up very quickly, the Met Office explains.
Although we won’t know the extent of these colder temperatures until later in the month, it looks as though the UK has longer to wait until the arrival of spring weather – so make the most of our glimpse of warmth and sunshine this weekend!
