Three people, including a woman in her 50s and a man in his 30s, have died as the remnants of Ophelia hit the British Isles.
As hurricane-force gusts battered the Republic of Ireland, the woman died when a tree fell on her car. The man died in a chainsaw accident while attempting to remove a tree downed by the storm.
About 360,000 homes and businesses in the Irish Republic, and 1,300 in Northern Ireland, are without power. In Wales, 4,000 homes are without power.
The Irish government has deployed the army.
An amber warning for Northern Ireland, Wales, south west Scotland and the Isle of Man is in force until 5 p.m.
It urged all road users to stay indoors and not travel unless their journey was absolutely necessary.