Storm Eunice reached the UK and Ireland early this morning, and severe wind warnings were put in place for most of the country.

The Met Office said strong winds are likely to cause flying debris, building roofs to fly off and power lines to be brought down.

The latest weather updates: Forecasters issue red threat-to-life warnings and people told to 'stay at home'

Gusts could reach 90mph, perhaps higher if an unusual phenomenon known as a sting jet occurs.

Here, Sky News explains what a sting jet is, how it forms and how likely it is with Storm Eunice.

What is a sting jet?

A sting jet is a small area of extremely intense wind that can form inside storms passing over the UK, Ireland and parts of north and central Europe.

Relative to the size of the storm they are very narrow - usually only around 30 miles across - and tend to last just three or four hours.

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But creating winds of at least 100mph, they are extremely dangerous and create significant damage and risk to life.

They are rare and were only formally recognised when one occurred during the Great Storm of October 1987 - when wind speeds reached 115mph and millions of trees were brought down.

How do they form?

Areas of low pressure that we see across the UK have weather fronts.

These fronts mark the boundary between areas of cold and warm air - and they bring bad weather.

Close to the two fronts we see focused streams of air called conveyor belts, which run up into the atmosphere.

The cold conveyor belt - a strong stream of cold air - pulls down into the storm ahead of the warm conveyor belt - also known as a dry intrusion.

Cold conveyors bring snow and rain, which evaporate and speed up the stream of cold air falling into the storm even more.

This is known as a sting jet - the 'sting in the tail' of the storm.

Read more: Met Office issues second red weather warning - Britons urged to stay home

How rare are they?

Sting jets are difficult to forecast because of their small size relative to the overall storm.

They were only formally discovered following the Great Storm of 1987 and have only happened a handful of times since.

But the biggest sign of a sting jet is violent winds seen at the surface.

After the storm starts to develop they can also be spotted on satellite images as the end of the cold conveyor belt forms a hook-shaped cloud that looks like the sting of a scorpion's tail.

What is the weather like in your area?

How likely is a sting jet with Storm Eunice?

Computer models have hinted at the chance of a sting jet as Storm Eunice crosses the UK, but even if the rare weather event doesn't happen, the winds from Eunice are set to be extremely dangerous and damaging.

Britons have been urged to stay home today with forecasters warning wind speeds could break records.

The Met Office has warned of "prolonged" power cuts, uprooted trees, damage to buildings and homes and "significant" travel disruption.

An amber warning covers England and Wales until 9pm today, while northern parts of England, southwest Scotland and Northern Ireland have a slightly less severe, yellow warning lasting from 7am to 6pm.

The most severe red-level warning is in place for part of the southwest of England and south Wales until midday today.

A separate, second, red warning is in place for London, southeast England, east of England and the southwest until 3pm this afternoon.