UK weather: Sudden stratospheric warming event 'now likely' - what is it and what does it mean? This winter parts of the UK have already been hit by freezing temperatures and heavy snow - but a weather event expected to take place in the coming days has sparked fears the country could soon face an icy blast. A major sudden stratospheric warming (SSW) event is "now likely", according to forecasters - and could bring the return of bitterly cold conditions before spring. Sky News weather producer Chris England says "sudden stratospheric warmings can lead to colder conditions over parts of the Northern Hemisphere through their interaction with the jet stream". But he warned these high pressure systems which are formed feeding cold air down from the north and east are not guaranteed. What is a sudden stratospheric warming event? SSW describes an event when "rapid warming occurs high up in the stratosphere", according to the Met Office, but it can have consequences in our weather down on the surface in the weeks that follow. This rapid warming in the stratosphere - between around 10km and 50km above the earth's surface - is so high we don't feel it on the ground. The event follows a weakening of winds in what's called the stratospheric polar vortex, high over the Arctic. "The cold air then descends very rapidly in the polar vortex and this causes the temperature in the stratosphere to rise very rapidly, as much as 50C over only a few days; hence the term sudden stratospheric warming," the Met Office says. This event can impact the shape of the jet stream as the cold air sinks - sometimes leading to a long spell of dry, cold weather across the UK and northern Europe. ....... https://uk.yahoo.com/news/uk-weather-sudden-stratospheric-warming-114400860.html

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UK weather: Sudden stratospheric warming event 'now likely' - what is it and what does it mean?

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UK weather: Sudden stratospheric warming event 'now likely' - what is it and what does it mean?

This winter parts of the UK have already been hit by freezing temperatures and heavy snow - but a weather event expected to take place in the coming days has sparked fears the country could soon face an icy blast.

A major sudden stratospheric warming (SSW) event is "now likely", according to forecasters - and could bring the return of bitterly cold conditions before spring.

Sky News weather producer Chris England says "sudden stratospheric warmings can lead to colder conditions over parts of the Northern Hemisphere through their interaction with the jet stream".

But he warned these high pressure systems which are formed feeding cold air down from the north and east are not guaranteed.

What is a sudden stratospheric warming event?

SSW describes an event when "rapid warming occurs high up in the stratosphere", according to the Met Office, but it can have consequences in our weather down on the surface in the weeks that follow.

This rapid warming in the stratosphere - between around 10km and 50km above the earth's surface - is so high we don't feel it on the ground.

The event follows a weakening of winds in what's called the stratospheric polar vortex, high over the Arctic.

"The cold air then descends very rapidly in the polar vortex and this causes the temperature in the stratosphere to rise very rapidly, as much as 50C over only a few days; hence the term sudden stratospheric warming," the Met Office says.

This event can impact the shape of the jet stream as the cold air sinks - sometimes leading to a long spell of dry, cold weather across the UK and northern Europe.

.......
https://uk.yahoo.com/news/uk-weather-sudden-stratospheric-warming-114400860.html