HURRICANE-FORCE winds of more than 170kmh that battered parts of the country yesterday were because of a "sting jet", Met Eireann said last night.
Sting jets occur when rapidly descending cold dry air, starting out high in the atmosphere, collides with warm moist air, forecaster Siobhan Ryan said
And the rare meteorological phenomenon was only discovered by scientists in the late 1980s.
"It is very unusual to have wind gusts of more than 173kmh," she said. "That's 105mph and that would be very rare.
"The sting jet looks like a scorpion's tail from space and starts at an altitude of three miles. As the cold air descends, it accelerates to more than 100mph at ground level," said Ms Ryan.
It is thought an increase in sting jet formations may be because global warming allows more heat energy to enter the atmosphere.
At about 5.40am yesterday, Met Eireann's station in Malin Head recorded a 10-minute mean windspeed of 126kmh -- a hurricane-force wind.
This exceeds the previous record windspeed record for Malin Head recorded on St Stephen's Day 1998. The recording came on a day of widespread disruption as flights were delayed or cancelled and road journeys made hazardous by falling trees.
More than 15,000 homes were without power at one stage as the force-12 storm hit Ireland in the early hours of the morning.
The worst affected areas were across Sligo, Mayo and Donegal where dozens of trees were uprooted and several main roads blocked.
Thatched holiday cottages on Cruit Island in west Donegal had almost all of their thatch removed.
ESB repair crews worked into the night to fix broken power lines, leaving just a few hundred homes without electricity last night. Eircom said it was working to restore telephone and internet services to 5,000 customers mainly in the West, south-west and north-west.
By 9pm last night ESB teams had restored power to all but 500 homes, a spokeswoman adding: "All but a handful will have power restored overnight."
The country's fishing fleet returned to ports and harbours around the country, ahead of the storm that created sea swells of up to 10 metres.
"This is typical weather for the time of year anyway, when the fishermen would be more cautious," said Dingle Harbour Master Brian Farrell.
In Ballinasloe, Co Galway, homes and businesses were without water for most of the day after a large tree was brought down by the high winds, damaging a major water main.
Crews from Galway County Council worked throughout the day in an attempt to repair the main at Creagh Junction.
Hundreds of trees were uprooted yesterday including an historic 19th Century pine at Kylemore Abbey in Connemara.
Onlookers gathered in the abbey grounds to see the felled 70-ft Cupressa Macrocarpa that had been planted by Mitchel Henry, who built Kylemore in 1870. "Due to the shallow soil at Kylemore, the roots are shallow, making the trees vulnerable to high winds," Abbey spokeswoman Brid Connell said.
A 200-year-old oak tree was also uprooted in Killarney National Park.
Motorists along the west coast of Clare had to contend with a fallen wall on the road between Ballyvaughan and Fanore. Flooding was reported between Borrisoleigh and Templemore, Co Tipperary.
Flooding is expected to remain a problem today in many areas with the worst hit roads being in rural parts of north and west Cork, Cavan, Kilkenny, Tipperary and Carlow.
The storms brought significant disruption to our airports as many flights were cancelled or delayed with high winds in London and Scotland adding to the chaos.
An ASDA store in Enniskillen and a leisure centre in Derry were both forced to close after the winds blew off roofs.
More than 10,000 homes across the North lost power in the storm with more than 40,000 homes affected in Scotland.
At Dublin Airport regional flights to Kerry and Donegal were cancelled and a number of flights to Scottish airports were delayed indefinitely with some passengers being told they would have to wait until today to travel. While most flights did depart, there were delays of up to two hours on some flights to London. But the ferocity of the storms shouldn't be a surprise, insisted Met Eireann's Siobhan Ryan.
"This is normal winter weather. We've had a couple of years of snow but this is the sort of weather we normally get," she said. Today will start off wet and windy in the North West with persistent heavy rain spreading to all areas later.