High winds and rain from Storm Debi were causing road closures and disruption to public transport across Northern Ireland.
Police have urged people to stay at home, with a yellow weather warning in place until 2pm.
The Met Office said Storm Debi would track across the region, with gusts of around 65mph expected through Co Antrim and Co Down.
One of the highest gusts recorded on Monday morning was a wind speed of 74mph at Killowen in Co Down.
NIE Networks said about 2,000 customers were without power, mainly around Craigavon, Newry and Downpatrick.
A number of roads were closed in the Ballymena area due to fallen trees and the Department for Infrastructure said there were reports of a landslip on the A2 Shore Road in Glenarm.
Cars struggled through flood water on roads surrounding Cookstown in Co Tyrone, while SDLP councillor Malachy Quinn said a woman in Coalisland had lifted her child over her head as floodwater impacted the King’s Row area.
The PSNI have also warned of floods in South Belfast.
Downpatrick in Co Down was badly affected by flooding in recent weeks, with many businesses under several feet of water after the nearby River Quoile burst its banks.
The Newry, Mourne and Down District Council said the A22 Killyleagh Road in Downpatrick had been closed at Quoile Bridge and that traffic was being diverted.
There were local reports of damage at the Quoile Bridge due to the amount of pressure it had been under with high water levels.
The canal in Newry, one of the areas worst affected by recent flooding, remained at a high level.
A number of businesses in the town had not yet reopened after significant water damage.
The Department of Infrastructure warned drivers to take care, saying fallen branches posed a risk on roads.
Translink said the bus station in Lisburn had been closed and that there were delays on the bus and train networks.
Flooding, heavy winds and fallen trees as a result of Storm Debi also caused significant disruption across the Republic of Ireland, with more than 100,000 homes and businesses without electricity at the peak of outages on Monday morning.
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