By Maria McCann
Storm Doris has reached nearly 90mph on its way to batter Britain as flights have been cancelled and commuters were warned they faced delays.
Doris is likely to damage buildings and send debris flying when it sets in at around 6am on Thursday, the Met Office has said.
An 87mph gust was recorded at Mace Head on the Galway coast in the Republic of Ireland in the early hours as Doris made its way east.
The UK was being battered by gales in the early hours.
#StormDoris will arrive from the west on Thursday, bringing damaging winds and heavy rain with heavy snowfall in the north pic.twitter.com/aBAlFeeNHS
— Met Office (@metoffice) February 22, 2017
Met Office meteorologist Mark Wilson said: "Winds are really starting to pick up now, mainly across western parts of the country."
Aer Lingus cancelled 12 flights between the UK and the Republic of Ireland in anticipation of the winds and Heathrow Airport warned customers to check their flights before travelling.
Particularly at risk are high-sided vehicles, caravans and motorbikes and drivers are being urged to take care behind the wheel.
A yellow weather warning for strong winds and heavy rain remains in place in Northern Ireland.
Meanwhile, snow is predicted to fall on higher grounds.
Storm Doris is expected to move on quickly, with the worst of the weather gone by Thursday evening.
While further Atlantic gusts will bring more rain and wind through the weekend and into next week, they are not expected to reach the heights of Doris.
Latest high gusts from NI is 74 MPH from Killowen Co Down. #Stormdoris doing her stuff. Lots of tree damage out there. #weatheraware
— Met Office warnings (@metofficeNI) February 23, 2017
AA spokesman John Snowling said: "The unpleasant combination of torrential rain, severe gales and heavy snow will create some very poor driving conditions, with the potential for roads to be affected by black ice, debris or standing water.
"Wind can also bring down tree branches, blow you off course or blow other vehicles into your path.
"Expect travel disruption as some roads will be treacherous."
Anyone affected by power cuts during the storm is encouraged to contact Northern Ireland Electricity for further information.
Storm Doris's appearance contrasts with Monday's temperatures, where visitors to Kew Gardens, west London, enjoyed the warmest day of the winter so far, at 18.3C (64.9F).
Drive with extreme caution this morning folks, there’s a lot of debris and fallen trees on many roads around the county!
— PSNI Fermanagh (@PSNIFermanagh) February 23, 2017
Dozens of flights into and out of Heathrow Airport are expected to be cancelled, with other passengers likely to experience delays.
A Heathrow spokesman said: "Strong winds and poor weather across the UK have resulted in approximately a 10% reduction to Heathrow's flight schedule.
"With Heathrow operating at more than 99% capacity, there are no gaps in the schedule that can be used for delayed flights and as a result, some passengers may experience disruption to their journeys today."