Winter has arrived suddenly in the UK with temperatures as low as -6.6°C recorded overnight in parts of the country.

A change in wind direction has brought cold Arctic air to Britain, bringing a sudden change in weather following an exceptionally settled start to the month. 

Meanwhile, an unusual weather phenomenon in the stratosphere is leading climate scientists to warn the UK could be in for a particularly cold winter. 

How long will the cold snap last?

The current cold snap began on Wednesday and has brought temperatures as low as 6.6°C to parts of the country.

According to the Met Office, the current cold weather has been caused by developments in the troposphere, the lowest part of the atmosphere. 

High pressure has changed the UK’s wind direction, bringing in colder air from the Arctic. 

The current cold snap is expected to be short lived, with milder and wetter weather expected over the coming weeks as Atlantic low pressure systems bring in rain and stronger winds. 

It comes after an exceptionally dry start to November, particularly across drought-affected areas in England.

What is the outlook for the rest of this winter?

While it’s impossible to reliably forecast the weather for the coming winter, climate scientists say there is potential for extreme cold in the UK due to an event happening right now in the Arctic.

Each year powerful winds, known as the polar vortex, develop high in the stratosphere over the Arctic during the colder months. 

When these winds weaken, they can bring unusually cold temperatures to the UK, as happened during the Beast from the East in 2018.

The polar vortex is currently experiencing an exceptionally early and unusual disruption, which could bring colder weather to the UK in December. The Met Office has said it is monitoring the situation, but said any impact would likely be short-lived.

However, current long range forecasts predict the polar vortex will weaken again in January or February, which could bring more extreme cold around that time. 

Many climate scientists believe this could be a result of the Super El Niño currently developing in the Pacific Ocean, which is expected to wreak havoc across the globe.  

El Niño is a natural climate phenomenon involving a significant warming of ocean water in the central and eastern tropical Pacific Ocean. It occurs every two to seven years and influences weather patterns across the globe. 

The Met Office has said the El Niño currently developing in the Pacific is the “strongest in living memory”.

However, there are various and sometimes conflicting ways an El Niño can influence the UK’s weather, meaning the outcomes are difficult to predict.

For example, an El Niño can also bring stormy weather to the UK via the troposphere, meaning a wetter and milder winter is also possible.