Storm Ophelia is set to bring “potentially deadly” gusts of up to 80mph from the Atlantic to Ireland and parts of the UK.
The Met Office has warned that remnants of Ophelia – which was previously classified as a hurricane – have “the potential for injuries and danger to life”.
The Republic of Ireland’s meteorological service, known as Met Eireann, extended a “status red” weather alert – its highest – across the entire country on Sunday night.
It described the storm as the most powerful hurricane to have ever been this far east in the Atlantic.
All schools and colleges have been closed, ferries cancelled, court sittings postponed and the Defence Forces put on standby.
The decision was taken following a special meeting of the Irish government task force on emergency planning.
Forecasters have warned of a “potential threat to life” and advised the public to stay off the roads and away from the coast during the height of the storm.
Dublin and Shannon Airports are advising passengers to check the latest flight information before travelling to the airport. Cork Airport said cancellations are likely.
The Met Office has issued an amber wind warning – meaning there is a “potential risk to life and property” – for Northern Ireland from 3pm-10pm today and has said there are likely to be problems on the roads with bridge closures, as well as disruption to rail, air and ferry services.
Schools in Northern Ireland have also been advised to close.
Forecasters said: “Gusts of 55-65mph are likely across Northern Ireland with 70-80 mph gusts in the far southeast.
“A smaller area of very gusty winds is then likely to run across Northern Ireland from the west with 65-75mph gusts possible for a short period of time in any one location.”
A less severe yellow weather warning is in place for much of Wales, Scotland, the North East, North West, South West and the West Midlands from 12pm to midnight.