Storm Ophelia is to batter the UK and Ireland with gusts of up to 80mph, with the Met Office warning of potential "danger to life".
Fears about the impact of strong winds have seen troops placed on standby and many public services in Ireland closed with schools, government buildings and courts among the services affected.
See also: Rare 'red sun' over UK caused by Ophelia
Remnants of Ophelia - which was previously classified as a hurricane as it made its way across the Atlantic - will reach home shores on Monday, resulting in "exceptional" weather - exactly 30 years after the Great Storm of 1987 killed 18 people.
Schools and colleges will also be closed in Northern Ireland, which is covered with an amber weather warning - meaning there is a "potential risk to life and property", issued when forecasters believe people need to be prepared to change their plans and protect themselves from the impacts of severe weather.
Forecasters are warning of flying debris, such as tiles blown from roofs, as well as large waves around coastal districts with beach material being thrown on to coastal roads, sea fronts and properties.
"This leads to the potential for injuries and danger to life," the Met Office said.
Very windy weather is expected across the entire region, while a yellow warning is in place for much of Wales, Scotland, north east England, north west England, south west England and the West Midlands.
In Ireland, Met Eireann has issued a "status red" weather alert for Galway, Mayo, Clare, Cork and Kerry, warning of severe winds and stormy conditions.
Met Office forecaster Luke Miall said that while storms with these wind speeds tend to happen at this time of year, the one on its way is "quite a substantial system", adding that he would describe it as "pretty exceptional".
Mr Miall said Ophelia will have gone through a transition on its way across the Atlantic but will still bring "hurricane-force" winds.
Taoiseach Leo Varadkar tweeted: "Defence forces being deployed in Red weather alert areas and on standby for further action (on Monday).
"Please check in with older neighbours and those who need medical care."
Meanwhile, airports are advising passengers in Ireland to check the latest information, with a number of Aer Lingus flights cancelled due to severe weather and the prospect of further cancellations with other carriers.
Dublin Airport and Shannon Airport are advising passengers to check the latest flight information before travelling to the airport, while Cork Airport said cancellations are likely.
Ryanair said: "We will inform customers in the event of any changes to our flight schedule and the latest flight information will be posted on the Ryanair.com website."
Bus Eireann said it will not run School Transport Scheme services on Monday in the counties of Waterford, Wexford, Limerick, Cork, Kerry, Clare, Galway and Mayo.
Loganair in Scotland is offering free flight changes on routes that could be hit by the severe weather conditions.
The airline said at the moment it still intends operating a normal full schedule on Monday and Tuesday.
The UK Military of Defence (MOD) has three battalions - 1,200 personnel in total - permanently on standby to assist with contingencies.
But an MOD spokesman said it has not yet received requests from any local authority for assistance.
Meanwhile, bookmaker Coral cut the odds on this month being the wettest October on record in the UK into evens (from 3-1) following a flurry of bets on Sunday morning.
The firm is offering 6-4 that the wind speed reaches as high as 100mph in mainland UK next week and 2-1 for there to be snowfall in October.