The Met Office issued an unusually high Severe Weather Warning — coded red for ‘take action’ — as heavy snows came fast on the heels of torrential rain.
There was traffic chaos as roads were closed and ferry sailings were cancelled.
The severe weather brought chaos to the electricity network forcing NIE to bring in extra resources to help restore supplies.
The damage to powerlines meant the extra 280 engineers, linesmen, call agents and admin staff were stretched to the limit.
Additional help was being brought in from the Republic.
Late last night emergency rescue teams were dispatched to the Glenshane Pass in Derry after reports several vehicles had become trapped by the blizzards.
Joe Dowdall from the North West Mountain Rescue Team said three rescue vehicles went to the area after a police request.
He said: “Two teams from the Donegal Mountain Rescue Team are also assisting. We believe there are a number of vehicles stranded.”
Members of the Mourne Rescue Team were also dispatched.
A Roads Service spokesman said last night it was aware a bus and cars were trapped. It had three gritters as well as a snow blowing machine out on the route.
The route from Belfast to Newtownards was partly blocked by a fallen tree and traffic on the motorways was reduced to a crawl.
The PSNI advised motorists to take “extreme care” on the roads last night and only leave their homes if “absolutely necessary”.
Several traffic collisions were reported by early evening.
An NIE spokeswoman said the snow and traffic collisions were “hampering” efforts to restore power to customers. Earlier it had reported that gale force winds had brought down lines and poles and caused 250 individual faults.
It estimated around 20,000 homes were without power due to damage to the network. Omagh, Dungannon, Enniskillen, Coleraine, Londonderry and Ballymena were worst affected.
“We continue to reinforce our teams on the ground and are working on new faults as quickly as it is safe to do so,” she said.
“We have invested heavily in our service and our systems have been thoroughly tested.
However, a rural network, like Northern Ireland’s is still vulnerable.”
Belfast’s Waterfront Hall was evacuated last night as powercuts forced both the cancellation of the city’s ‘Youth Oscars’, and also a performance of one of Ulster’s best known plays, Over the Bridge.
Police warned of a three-vehicle collision in Moneymore and a two-vehicle collision which left Frosses Road blocked.
Torrential rain in the east yesterday also caused its share of disruption, with motorists reporting a veritable river along the Belfast to Bangor Road.
Police warned of flooding in Dunmurry, while roads around Stewartstown were impassable.
A Roads Service spokeswoman said: “Based on Met Office advice the public are advised not to travel on high ground unless absolutely necessary.”
All P&O Express sailings between Larne and Cairnryan were cancelled, but passengers were being transferred to conventional ferry sailings. Stena sailings between Belfast and Stranraer were also cancelled.
Local football fixtures were called off due to the weather.
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