A post-tropical cyclone Ophelia is set to sweep across Ireland on Monday and is expected to cause severe damage. The storm, which was downgraded from a hurricane overnight, is the worst the region has seen in over 50 years.

Forecasters predicted winds of up to 105 km an hour across Northern Ireland but gusts could reach 129 km an hour in the far south-east, BBC reported. The Republic of Ireland’s weather service Met Éireann said “violent and destructive gusts are forecast with all areas at risk and in particular the southwest and south in the morning, and eastern counties in the afternoon”, The Irish Times reported.

Met Éireann said gale-force winds were expected to hit the south by early Monday morning and gradually spread northwards across the country during the day. The severe warning issued by the weather services runs from 6 am local time on Monday until midnight.

All schools and higher education colleges in Northern Ireland would remain closed, the country’s Education Ministry announced on Sunday. Northern Ireland’s transport authority Translink warned of possible disruption of bus and rail services, while flight cancellations were confirmed at the Belfast City Airport and the Dublin Airport. All hospital outpatient appointments in the Republic have been cancelled.

In the Republic, the government’s crisis management committee met on Monday and warned against all unnecessary travel while the storm passes. Irish Prime Minister Leo Varadkar tweeted that defence forces would be deployed and remain on standby.

Underlining the severity of the storm, Met Éireann warned that the storm could be as bad Hurricane Debbie of 1961 that caused 18 deaths.