Heavy snow, rain, thunderstorms and wind have caused disruption across much of Britain as a band of "severe" weather rolled across the UK.
Glasgow Airport said the snow had caused operations to be "temporarily suspended".
It added: "Our winter operations teams are working to reopen as soon as possible. We advise passengers to check with their airline for updates and apologise for any disruption."
Up to 5cm of snow fell overnight causing Glasgow Airport to temporarily ground flights.
Forecasters predict those conditions will head eastwards before turning into sleet and rain.
Among the flights cancelled was a Flybe service to Belfast City at 9am this morning.
INFO | We regret that operations are temporarily suspended at the airport. Our winter operations teams are working to reopen as soon as possible. We advise passengers to check with their airline for updates and apologise for any disruption.— Glasgow Airport ✈️ (@GLA_Airport) December 29, 2017
The airport has since reopened and staff remain on standby to monitor the situation.
UPDATE | The airport is now open and operational again. Our winter operations team will remain on standby throughout the day to monitor weather conditions (FR)— Glasgow Airport ✈️ (@GLA_Airport) December 29, 2017
Parts of northern England and Scotland discovered thick blankets of snow on Friday morning, with the south coast lashed by torrential downpours, lightning and strong winds.
Forecasters warned of disruption to travel and potential power outages throughout Friday as the band of "severe" weather moves in from the east.
An amber warning of snow in West Yorkshire, the South Pennines and places such as Rochdale and Burnley is in place until 11am and a wider yellow warning for snow has been issued for southern and eastern Scotland, northern England and the Midlands until 3pm.
The heaviest snowfall of 5cm-10cm is expected in parts of northern England and up to 15cm over higher ground.
Across the south-west coast meteorologist Emma Sharples said a "squally feature" moving eastwards was "quite active and giving some high rain rates", with thunder and lightning and gusts of up to 50 mph recorded.
A yellow warning has been issued by the Met Office for strong winds expected over parts of south-west England and southern Wales across to Greater London, bringing "potent, heavy showers with a chance of hail and thunder" as the system moves eastwards.
Devon and Cornwall Police said the A39 near Bideford in Devon was partially blocked due to a fallen tree and there was flooding on the A3075 near Newquay in Cornwall.
Elsewhere snow caused disruption across many roads, with Cumbria Police warning on Twitter that all routes in the south of the county were affected, as well as the M6.
Highways England has issued a severe weather warning and urged people to plan their journeys, monitor weather reports and pack a snow kit of blankets, food, water and a shovel if they really need to travel.
The RAC said it expected to attend "in the region of one breakdown every 10 seconds through the course of Friday".