Storm Darragh has hit the island of Ireland, with seven counties subject to red wind warnings overnight.
Airports have warned of potential disruption and some ferries have been cancelled. A series of festive events have also been called off across the weekend.
Authorities on both sides of the border had made preparations ahead of the worst of the storm making landfall.
Met Eireann’s highest level of alert cover counties Mayo, Clare, Galway, Donegal, Leitrim, Sligo and Wicklow.
Taoiseach Simon Harris urged those living in areas covered by red warnings to take them “extraordinarily seriously”.
“A red weather warning does mean do not travel during that period of time, and even though it is a Friday night and coming up to the Christmas season, I’d really encourage people to heed that advice and indeed to follow closely weather advice in the hours ahead,” he said.
“Of course, there’s an orange weather warning for the rest of the country as well. So, really, people in that area should avoid any unnecessary travel at all. It is important people take these warnings very, very seriously in terms of protecting life in the hours ahead.”
In Mayo, the warning came into effect at 9pm on Friday and is place to 3am.
For Clare and Galway, the alert is in place from 9pm to 2am.
In Donegal, Leitrim and Sligo, the warning came into effect at 10pm and is in place until 3am.
The red warning for Wicklow is in effect from 1am to 6am on Saturday.
ESB Networks said the high winds are expected to cause damage to electricity infrastructure, particularly in counties subject to the red warnings.
The rest of the Republic of Ireland will be covered by a Met Eireann orange wind warning. In Munster and Connacht, that warning came into effect at 8pm on Friday and will extend to 10am on Saturday.
The orange alert for Leinster and counties Cavan, Donegal and Monaghan came into effect two hours later at 10pm and will also lift at 10am on Saturday.
A Met Eireann yellow wind warning covering the whole state came into place at 3pm on Friday. It will remain in effect after the orange warnings lift and will be in place until 3pm on Saturday.
A yellow rain warning for Connacht, and counties Clare, Donegal, Cavan, Monaghan, Longford, Louth, Meath and Westmeath came into place at 10am on Friday and will lift at 10am on Saturday.
In Northern Ireland, the Met Office has issued an amber wind warning covering the whole region from 1am on Saturday to 9pm.
A yellow rain warning came into effect in Northern Ireland at 3pm on Friday and will lift at 12pm on Saturday. A yellow wind warning also came into place at 3pm on Friday.
