Winds are up to 80mph on the north and east coasts of Northern Ireland.
Police warning motorists of snow and black ice on some roads, especially south Tyrone and between Coleraine and Garvagh, Co Londonderry.
The Foyle Bridge in Londonderry city was closed to all high-sided vehicles, with a 30mph speed limit.
Ferry services between Scotland and Northern Ireland were severely disrupted, with sailings from Cairnryan suspended until early afternoon.
With the worst of the storms now likely to affect Scotland and Northern Ireland, the severe weather has caused four deaths across the UK.
A man’s body was pulled from the River Rothesay in Ambleside in Cumbria, while a woman died in a river in Gwynedd, North Wales.
A woman was killed in a car accident in Shrewsbury, Shropshire, last night and a man died in a multiple-collision crash near Bodmin in Cornwall on Sunday night.