The Polar Vortex
Experts are predicting this winter might just be a cold one. We've become accustomed to mild, wet winters but changes to something called the polar vortex mean early indications suggest temperatures will be much colder this time round.
At the beginning of November, the Met Office released their three monthly forecast, taking us up to the end of January. This is used by the government and other agencies to help them prepare for the winter and allows them to increase their stocks of de-icing salt if necessary. This forecast suggests that the polar vortex will influence our weather systems and cause colder weather than usual.
The polar vortex is high atmosphere winds that spin around both the Earth's poles. These winds encircle areas of low pressure and cold air, insulating us from arctic blasts. For the last few years the North Pole's polar vortex has been spinning very fast. This has trapped the cold air and also drawn warm air northwards, resulting in our weather systems being dominated by south westerly winds, which are characteristically warm and wet.
However, this year the polar vortex appears to be slowing, meaning it is not spinning in such a tight circle. This is allowing the colder polar air to drop down to the mid latitudes, i.e. where we are. Therefore, we are set to experience a lot more north easterly winds, which are much colder and can pick up moisture over the North Sea, creating snow fall. Whilst the polar vortex will not be the only system influencing our weather in the coming months, its change does mean that there is a higher chance of a harsher winter.
The impact of the weakened polar vortex has already been seen elsewhere on the Globe. Russia is currently experiencing much more widespread snowfall and cold weather than they normally would expect at this time of the year. The polar vortex last made headline in 2014 when it weakened, causing severe snowstorms and cold weather throughout the US.
However, this year the polar vortex appears to be slowing, meaning it is not spinning in such a tight circle. This is allowing the colder polar air to drop down to the mid latitudes, i.e. where we are.
Whilst it's unlikely we'll see the type of harsh winters that the US and Russia have, it does suggest that we should be preparing for snow and ice across the country. So make sure your hats and scarves are at the ready!