What is the Beast from the East, how will it affect UK weather and what is a polar vortex?
BRITAIN was battered by icy weather last week as the polar vortex nicknamed "Beast From The East" spiralled in from the arctic.
Here's the lowdown on the extraordinarily cold weather event – and when it collided with Storm Emma.
Why is it called the "Beast from the East"?
Essentially because the frigid weather is due to be swept in from over Russia - in the East.
Winds from Siberia pushed in from the east, causing the mercury to plummet - with even daytime temperatures struggling to rise above zero.
It caused widespread disruption and water companies have only just restored supplies to most customers after days of weather-related problems.
The phrase Beast from the East has been used to describe things other than weather, including a wrestling show in Tokyo and a heavy metal album by American band Dokken.
What's the latest weather forecast in the UK
Weather warnings of snow and ice are in effect for many parts of the country on Thursday morning - as police warn of tricky driving conditions.
Forecasters warned of sleet and snow for upland areas and some lower ground into Thursday morning in central and northern England and Wales.
The Met Office warning, covering the East Midlands, North West England, West Midlands, Yorkshire and Humber and Wales came into force just after midnight and runs until 11am.
North Wales Police said snow was "coming down quite hard" in the region and advised motorists to be careful.
What is a polar vortex?
A polar vortex is a mass of desperately cold air that sits above the Earth’s north and south poles.
This dense, cold air is controlled by a large pocket of low pressure, which rotates in an anti-clockwise direction at the North Pole and clockwise at the South Pole.
The strength of a polar vortex varies from year to year. When it is strong, the vortex is concentrated over the Arctic or Antarctic area.
But when it is weak – which is more frequent – it can split into two or more freezing vortices.
The phenomenon associated with wintry weather is known as a Sudden Stratospheric Warming.
These cover a larger area and can move south to Canada, the USA and Europe, increasing the risk of air temperatures decreasing to potentially dangerous levels.
When did the Beast from the East collide with Storm Emma?
Storm Emma clashed with the Beast from the East last Thursday which caused widespread disruption across the UK.
Forecasters issued red weather warnings of a danger to life as the storm's 70mph winds hit the polar vortex — bringing deadly snowdrifts and a -15C windchill.
And a hazardous mix of melting snow, high tides and heavy rainfall prompted 15 flood alerts from Sunderland to Cornwall - with 51 areas facing flooding.
Yorkshire and Humber and Wales came into force just after midnight and runs until 11am today.
North Wales Police said snow was "coming down quite hard" in the region and advised motorists to be careful.
The Met Office said up to 10cm of snow was expected on higher ground, while much lower ground was unlikely to see any.