There have been many headlines in recent days proclaiming a return of the ‘Beast from the East’ and ‘triple polar vortex to trigger heavy snow’ with bookies reportedly cutting the odds that this month will end as the coldest January on record following a sudden stratospheric warming high above the Arctic.
So, just how much truth lies behind these headlines and what can we really say about the weather for the coming month? Our Deputy Chief Meteorologist Jason Kelly explains.
Well, it is true that a sudden stratospheric warming has happened. The warming started around 22 December 2018 and the winds at around 30km above the North Pole have now reversed from westerly to easterly. At ground level we know that sudden stratospheric warmings tend to weaken the UK’s prevailing mild westerly winds, increasing the chances of us seeing colder weather a couple of weeks after a sudden stratospheric warming.
However, it’s important to note that not all sudden stratospheric warmings lead to colder-than-normal conditions over the UK and there are other global weather factors that result in blocked weather patterns and possible colder weather for us. These include El Niño and the Madden-Julian Oscillation that were well signalled in our 3-month outlook as early as the end of November.
Certainly, for the first ten days of January there is no strong signal for a cold easterly flow that was associated with the ‘Beast from the East’ last winter, and it’s too early to provide detailed forecasts for what the weather will be like for the remainder of January.
Our current 6-30 day forecast points to the likelihood of more mobile conditions before the arrival of anything that might potentially be colder. Towards the end of January, however, there is an increased likelihood of a change to much colder weather generally, bringing an enhanced risk of frost, fog and snow.
This cold spell is by no means certain though, and if you are hoping for, or need to prepare for possible cold and/or snowy weather, please keep up to date on our forecast pages and by following us on Twitter and Facebook. Our app is available for iPhone from the App store and for Android from the Google Play store.