A number of homes have been flooded in counties Down and Tyrone following hours of heavy rain and wind caused by Storm Bert.
A number of residents in Dundonald are stuck in their houses due to the flood water while there has also been flooding in Coalisland,BBC reported.
Travel is heavily disrupted, with roads and train lines affected by flood water, fallen trees and other debris.
The railway line between Belfast and Antrim remains closed, while the line between Belfast and Dublin has reopened after being shut earlier, public transport operator Translink said.
About 3,500 customers are without power, with most of those in the south east and north west.
Houses near Moat Park, in Dundonald on the outskirts of east Belfast, have been badly hit by flooding, with firefighters at the scene to pump the water away.
Meanwhile, homes at Kings Row, Coalisland, have also been hit.
Mid Ulster councillor Dan Kerr told BBC News NI he had been contacted by three of four residents whose homes have been flooded at Kings Row.
He said the firefighters and staff from the Rivers Agency were at the scene and sandbags had been secured from a nearby Gaelic Athletic Association (GAA) club.
The fire service are pumping water at Park Avenue, where a number of residents cannot get out of their houses.
Kelly Kitchen’s son and his partner are among those residents. She says her son told her he woke this morning after 09:00 to find his house had been flooded.
He hasn’t been able to leave. A video of his home shows a fridge floating in the kitchen and a couple of feet of dirty water on the ground floor.
The fire service arrived after 09:00 and have been pumping the excess water since. It is receding slowly as residents watch. Some have gone to the nearby church hall to stay warm and dry while the operation continues.
Yellow warnings for rain, wind and snow were in force for the whole of Northern Ireland until 11:00 GMT on Saturday.
The strongest winds in Northern Ireland - at 67mph - were recorded in Ballypatrick, County Antrim, while Derrylin in County Fermanagh recorded a quarter of its average November rainfall in 12 hours overnight.
Police officers advised "extreme caution" to anyone driving in the Causeway Coast and Glens Council area due to snow early on Saturday morning.
The TrafficWatchNI service reported "very difficult driving conditions" on some higher areas including the Glenshane Pass, Windyhill Road in Limavady and Glenpark Road, Omagh.
A gritter vehicle got stranded in snow on the Coleraine Mountain Road, which was closed for a period.
