Eunice is likely to cause widespread damage, power outages and travel disruption, particularly across south-west England and south Wales, and the east of England, including London, with a rare red "danger to life" weather warning in place.
The red alerts - which was last issued in November 2021 before Storm Arwen - also warns of damage to buildings and homes, with roofs blown off and power lines potentially being brought down.
The red weather warning for London and the south-east is the first ever issued for that region.
Met Office Chief Meteorologist Frank Saunders said: “An active jet stream is helping to drive low-pressure systems across the country, with both storms set to cause some disruption."
The government held an emergency COBR meeting on Thursday to discuss the response to both Storm Dudley and Storm Eunice, and it was announced that the Army will be on standby to deal with the impact.
When is Storm Eunice due?
Storm Eunice will hit from the west of country, bringing strong winds to southern and central areas, as well as some snow for northern areas from early on Friday.
The forecast after Storm Eunice continues to look unsettled with the potential for more wet and windy conditions over the weekend and the start of next week.
Which areas could be affected?
Much of the UK will be affected by Eunice, says the Met Office.
The first weather warning will come into force from 7am along the coastline of Devon, Cornwall and Somerset as well as the south coast of Wales due to the combination of high tides, strong winds and storm surge.
From 10am a second red weather warning for wind will cover Greater London, Kent, Surrey, Essex and East Sussex between 10am and 3pm.
North Cornwall, north Devon and Sharpness in Gloucestershire are feared to be amongst the worst-hit areas due to the tidal impact from the surge and very high spring tides.
In Cornwall, residents are being urged to take precautions and only travel if absolutely necessary, while people in north Somerset are being encouraged to stay at home.There is a risk of “flying debris resulting in danger to life”, the Met Office warns, and “damage to buildings and homes, with roofs blown off and power lines brought down.
The public are urged to stay at home and the Army is on standby.
Which towns and cities are covered by the red weather warnings?
East of England: Cambridgeshire, Central Bedfordshire, Essex, Hertfordshire, Luton, Southend-on-Sea, Suffolk and Thurrock.
London and Greater London
South-east England: Bracknell Forest, Brighton and Hove, Buckinghamshire, East Sussex, Hampshire, Isle of Wight, Kent, Medway, Oxfordshire, Portsmouth, Reading, Slough, Southampton, Surrey, West Berkshire, West Sussex, Windsor and Maidenhead and Wokingham.
South-west England: Bournemouth Christchurch and Poole, Dorset, Wiltshire, Bristol, Cornwall, Devon, Gloucestershire, Isles of Scilly, North Somerset, Somerset and South Gloucestershire.
Wales: Bridgend, Caerphilly, Cardiff, Carmarthenshire, Monmouthshire, Neath Port Talbot, Newport, Rhondda Cynon Taf, Swansea and Vale of Glamorgan.
What about the rest of the UK?
An amber weather warning, the second-highest alert level - for high winds is in place for the rest of England and Wales south of Manchester from 5am to 9pm on Friday.
Meanwhile, yellow weather warnings, the next level down, for wind and snow are in force for a large part of Scotland – where blizzards are predicted – and the whole of Northern Ireland, with a yellow weather warning for wind across northern England.
The Met Office said that, where snow does fall, the high winds are likely to create blizzard conditions and could measure up to 20cm on the ground in some places.
What have the experts said?
"Storm Eunice is expected to track eastwards from early on Friday, bringing the most significant winds to the central and southern areas of the UK, with some gusts possible in excess of 95mph in exposed coastal areas," said Mr Saunders.
Katharine Smith, Environment Agency Flood Duty Manager, said: "Strong winds could bring coastal flooding to parts of the west, southwest and south coast of England, as well as the tidal River Severn, in the early hours of Friday morning.
"This is due to Storm Eunice resulting in high waves and potential storm surge coinciding with the start of a period of spring tides."
How strong is Eunice?
The Met Office said Eunice will bring "significant winds" to central and southern areas of the UK.
Exposed coastal areas could see wind gusts in excess of 95mph, while inland areas could still see gusts of around 80mph.
How will people be impacted?
Due to the strength of the gusts, the Met Office warned they bring the potential for flying debris resulting in a danger to life, fallen trees, damage to buildings and travel disruption.
People are being urged to stay at home and the Army has been placed on standby.
Brisk winds in Northern Ireland, northern England and southern Scotland could cause blizzard-like conditions and drifting of lying snow, reducing visibility, and making driving conditions difficult.
Other threats include railway lines being closed with delays and cancellations to public transport, ferry services and flights, and large waves plus “beach material” being thrown on to coastal roads, seafronts and homes, which could result in flooding for some coastal properties.
What is a weather bomb and why has Storm Eunice been identified as one?
A 'weather bomb' is defined as an intense low pressure system with a central pressure that falls 24 millibars in a 24-hour period. What that means is a deep area of low pressure bringing stormy conditions, which is likely to mean gale-force winds and wintry showers.
What is a 'sting jet' and could Storm Eunice form one?
The Met Office said the dangerous weather phenomenon known as a sting jet – a small area of highly intense wind inside a storm – could form later on Friday.
Relative to the size of the storm, the sting jet is narrow, often 30 miles across, and only lasts three to four hours. Regardless, with gusts of wind exceeding 100 mph there is clearly still the risk of damage. The Great Storm of 1987 was a perfect example of this.
What can we expect under a red weather warning?
The Met Office anticipates significant damage to infrastructure and power lines, and threats to coastal properties. The agency said to expect:
Flying debris resulting in danger to life
Damage to buildings and homes, with roofs blown off and power lines brought down
Uprooted trees are likely
Roads, bridges and railway lines closed, with delays and cancellations to bus, train, ferry services and flights
Power cuts affecting other services, such as mobile phone coverage
Large waves and beach material being thrown onto coastal roads, sea fronts and homes, including flooding of some coastal properties
Warning of floods due to the strong gusts, Ms Smith advised: “Please remember to take extreme care on coastal paths and promenades.
"We urge people to stay safe on the coast and warn wave watchers against the unnecessary danger of taking ‘storm selfies’.
"Flooding of low-lying coastal roads is also possible and people should avoid driving through flood water as just 30cm of flowing water is enough to move your car.
“You can check your flood risk, sign up for free flood warnings and keep up to date with the latest situation at https://www.gov.uk/check-flood-risk, call Floodline on 0345 988 1188 or follow @EnvAgency on Twitter for the latest flood updates.”
How did Eunice get its name?
The Met Office takes name suggestions and creates an alphabetical list of storm names which are attributed to them once they are likely to happen.