Gusts of up to 80mph have been recorded as Storm Gareth, the seventh storm of this winter, swept through Northern Ireland.
A Met Office yellow warning which was in place until 12:00 GMT on Wednesday has now been cancelled.
Winds were at 69mph (111km/h) at Orlock Head, County Down while at Malin Head, County Donegal, gusts reached 81mph.
The Met Office said the worst of Storm Gareth had now passed but strong winds and rain would persist on Wednesday.
Gusts of up to 60mph are still expected in coastal areas while the weather warning remains in place.
Around 10,800 Northern Ireland Electricity (NIE) customers were left without power as Storm Gareth swept in.
An NIE spokesman said power has now been restored to the majority of homes and about 500 customers are currently without power.
Crews have restored power to more than 10,000, with 500 customers still without electricity.
NIE is working to reconnect those still affected.
In Portstewart, a children's playground was flooded by waves crashing over the sea wall.
The Department of Infrastructure said they dealt with more than 100 incidents connected to Storm Gareth.
A spokesman said the north and west of Northern Ireland were badly affected by fallen trees and branches.
The A6 road in Antrim and the B18 road in Ballymena were both closed for a short time.
In Londonderry, the Foyle Bridge was closed to high-sided vehicles.
Both the Broomhill Avenue in the city, which had closed because of fallen trees on Tuesday, has now reopened as has the Liskey Road in Strabane.
Translink earlier warned that there may be "some delays and disruption possible to bus and train services" on Wednesday.
P&O ferries said sailings between Larne and Cairnryan Dublin and Liverpool had been cancelled due to the weather but ferries between Dublin and Liverpool were sailing on Wednesday morning.
The Atlantic system was named by the Irish weather service, Met Éireann, which issued a Status Orange warning for four counties in the Republic of Ireland.
That is the second highest warning level, and affected Counties Donegal, Sligo, Leitrim and Mayo.
Almost 2,000 homes in the Republic of Ireland experienced power cuts.