Weather: Storm Barbara causes power cuts in Northern Ireland, Storm Conor due to roll in on Christmas Day
Follow live updates on the weather and traffic situation below
Engineers have restored power to around 1,000 Northern Ireland residents who were without electricity on Friday as Storm Barbara moved in from the Atlantic.
Engineers worked to repair faults, mostly in south Down, as gusts of wind up to 70mph battered the coastline.
Electricity cuts were also reported in Armagh and Fermanagh. NIE said that power has now been restored to all customers.
Storm Barbara, which brought gales and rain on Friday, will be followed by Storm Conor on Christmas Day and Boxing Day.
Conor is expected to bring gusts of 50 to 60 mph over Northern Ireland and northern England and up to 70 mph to parts of Scotland on Christmas Day.
There has also been cancellations to some ferry services while revised schedules and cancellations of flights to the islands are also expected.
An AA spokesman said: "Drivers are going to have to be very, very savvy about how they travel over the next four to six hours," adding: "All in all, it's a pretty nasty cocktail of potential road disruption."
The greatest impacts are expected to be over the Northern Isles on Boxing Day where the potential for gusts in excess of 80 mph enhances the risk of disruption to power supplies, with large waves affecting coastal areas.
From Tuesday 27 December onwards indications are that high pressure will once again start to dominate bringing more settled weather with the risk of overnight fog for southern areas while parts of the north remain blustery.
Storm Conor is the third storm of the 2016/17 winter season. The other two storms were Angus and Barbara while the next one after Conor will be Storm Doris.
Readers can get the latest live updates on the weather and traffic situation below.
Northern Ireland Electricity has said it is prepared for blackouts and has initiated an escalation plan with emergency crews, engineers and call handlers on standby.
"We would like to remind customers that if they do lose electricity supplies they should report the fault online at nienetworks.co.uk or call the NIE Networks Customer Helpline on 03457 643 643. Customers can also follow us on Twitter @NIElectricity for regular updates," said Julie Carson from NIE Networks.
Ferry companies have urged passengers to keep checking their websites for information about potential disruption to crossings.
Irish Ferries cancelled three crossings on Friday from Dublin to Holyhead leaving at 8.45am, 10.45am and 2.30pm. Updates can be found at irishferries.com
Why has the weather changed?
The Met Office says that recent conditions in North America – with cold Arctic air sinking far southwards – has brought unusually cold weather to parts of North America. This cold air encounters relatively warm air in the western Atlantic.
This creates a strong temperature gradient along the boundary between the two air masses which will strengthen the jet stream – a high-altitude fast-flowing wind which often brings low-pressure systems and storms to our shores.
As the jet stream then comes east across the Atlantic, it drives areas of low pressure towards the UK, with associated spells of strong winds and rain.
Storm Barbara and Storm Conor are both rapidly developing and deepening as they approach the UK and Ireland.
This process is known as rapid or 'explosive cyclogenesis' and leads to the formation of what is commonly called a 'weather bomb’.
A 'weather bomb' is defined as an intense low pressure system with a central pressure that falls 24 millibars in a 24-hour period, leading to more vigorous winds.
This phenomenon is fairly common during the winter when the rapid deepening usually happens over the Atlantic.