High winds across the country have left some 5,000 households without electricity tonight while fallen trees and flooding have blocked a number of roads.
People are being advised to stay indoors and not to make any unnecessary journeys as a powerful storm sweeps the country.
Winds of up 100 mph have been recorded in the north west with counties Galway, Mayo and Donegal most affected.
Earlier a lorry driver was killed when his vehicle was blown off Derry's Foyle Bridge by gale-force winds.
The lorry fell hundreds of feet from the bridge onto mudflats. The driver from Co Armagh has not yet been named.
Another lorry overturned and collided with a car while crossing the Faughan Bridge on the Limavady Road near Derry. Two people were injured in the crash.
The ESB said tonight that 5,000 homes, mainly in the west, were without power.
Emergency crews, including the civil defence teams, were on standby along the western coast, which was expected to be the worst hit area. The high winds were expected to sweep eastwards during the evening.
In Malahide in Co Dublin, a high tide caused flooding on Bissets Strand, Strand Road and Estuary Road. Motorists were advised to avoid the area.
A number of schools in the north west announced early closures today.
Ferry services to offshore islands in the west were also cancelled.
The roof of the Catholic Church at Tulsk, Co Roscommon, was reported to have blown off.
The seas off the west coast were described as "mountainous" with swells of up to 20 foot.
A fallen tree at Millicent Bridge in Sallins completely blocked the road, with gardaí asking motorists to take an alternative route.
The N20 between Croom and Banogue in Limerick was partially blocked by a tree, while in Clare, a telephone pole was blown down on the Sandfield Road in Ennis.
Motoroists are asked to avoid the area if possible. In Co Down flooding closed the Newry-to-Warrenpoint dual carriage-way for a time this afternoon.
AA Roadwatch urged drivers to slow down and those driving high-sided vehicles are asked to take particular care.
Weather conditions have also led to flights being cancelled. Aer Arann has cancelled some of its Galway and Kerry services, with flights from Cork and Sligo also affected.
Aer Lingus has also been forced to cancel a flight due from London Heathrow at 5.35 p.m., while Ryanair has cancelled some flights to and from London during the course of the day.
Ferry services to offshore islands in the west have been cancelled. However, Stena and Irish Ferries sailings are all running to schedule, with the exception of ferries that are in dry dock.
Irish Water Safety has warned people to be on the alert for dangerous flood conditions.
Mr John Leech, Irish Water Safety's chief executive, said motorists needed to be particularly vigilant to avoid flooded areas on roads and near rivers.
He also warned people crossing flooded areas that fast-moving water could exert pressure of up to four times its speed against a person's legs.
