A weather event is taking place high above the North Pole which could lead to another 'Beast from the East' hitting the UK in the coming weeks.
About 6-30 miles (10-50km) up in the layer of the atmosphere called the stratosphere, there is a Sudden Stratospheric Warming (SSW) occurring where temperatures could increase by up to 50C over a few days.
It is so high up that we do not feel the 'warming' ourselves.
However if the weather 'disturbance' heads downwards to the Earth's surface, we could see knock-on effects on the jet stream within weeks, which in turn would affect our weather conditions, making it unusually cold across Europe.
The 'Beast from the East' winter storm in late February 2018 is a stark reminder of what an SSW can bring.
Biting winds from Siberia brought icy and snowy conditions across the country for a period of a couple of weeks and led to several deaths.
The Met Office said the latest event is more likely to bring more cold weather without heavy snow, though it is difficult to predict.
Over the festive period, snow fell in large parts of the country, including the Midlands.
The agency is also tracking a La Nina weather pattern in the Pacific, which could bring wet and stormy weather as it increases the UK's chances of westerly winds.
Met Office spokeswoman Nicola Maxey said: "You've got the two events happening at the same time so they vie against each other in a sense.
"They're sort of fighting for influence over the UK, we're a very small dot in the middle of the ocean."
Ms Maxey continued: "The feeling at the moment is that we may see some colder weather towards the end of January into February, but probably the sort of weather that we're seeing at the moment, as opposed to what is popularly perceived as a Beast from the East."
Sky's weather producer Jo Robinson said: "A Sudden Stratospheric Warming event has taken place and there are signs of another later in the month. The impact on the UK is uncertain, but more often than not it leads to a cold spell in the days or weeks ahead.
"If the stratospheric polar vortex breaks down completely, this can trigger a change from westerly to easterly winds at lower levels too. On average, the likelihood of a cold weather event across the UK following a SSW event is about 70%.
"In the meantime, it will remain cold through the rest of this week, with some significant snow possible on Thursday and Friday as a weakening feature moves south. Through the weekend, temperatures are likely to pick up and it looks milder and more unsettled next week."
A new study, led by researchers at the Universities of Bristol, Exeter and Bath, helps to shed light on the very cold weather that may soon be in store.
The study, published in the Journal of Geophysical Research, involved analysing 40 SSW events which occurred over the last 60 years.
Lead author Dr Richard Hall said there was an increased chance of extreme cold, and potentially snow, over the next week or two.
He said: "While an extreme cold weather event is not a certainty, around two thirds of SSWs have a significant impact on surface weather.
"What's more, today's SSW is potentially the most dangerous kind, where the polar vortex splits into two smaller 'child' vortices."
Co-author Dr William Seviour said: "Our study quantifies for the first time the probabilities of when we might expect extreme surface weather following a sudden stratospheric warming (SSW) event.
"These vary widely, but importantly the impacts appear faster and stronger following events in which the stratospheric polar vortex splits in two, as is predicted in the currently unfolding event."