Gusts reaching almost 120mph were recorded on the summit of Cairn Gorm at 11am and winds of 60mph to 70mph are expected across the west and north-west of Scotland later.
The worst of the conditions are due over the far north of the country and the Western and Northern Isles, but disruption to power supplies and travel is expected to be felt across the UK.
At midday on Friday, gusts of 74mph were recorded on South Uist, 67mph on Stornoway while Edinburgh recorded gusts of 53mph. Strong winds forced city bosses to temporarily close some of the capital’s Christmas attractions.
A number of properties in Aberdeenshire, Moray and on the Western Isles lost power, with engineers working to reconnect supply.
Scotland’s transport minister Humza Yousaf said: “Ministers have been receiving regular updates on the impact of the severe weather across this week.
“We are expecting the worst of the disruption today when winds are expected to reach 90mph.
“Our transport operators and trunk road operating companies are working hard to keep services and roads running, safety has to be our top priority, so we are seeing delays and cancellations to flights and ferries.
“We would urge everyone to check the latest sources of information before they travel and keep in mind that the situation can change quickly.”
Two separate yellow “be aware” wind warnings are in place, one covering northern parts of the UK where gusts of 60mph to 70mph are expected quite widely, and one for more southern areas, where a narrow and intense band of heavy rain and gusty winds could lead to some disruption.
There have been cancellations to some ferry services while revised schedules and cancellations of flights to the islands are also expected.
The situation is being replicated on the railways, where a revised timetable is in place, with travellers being advised to check the latest conditions before they go.
Festive travellers have been dealt another blow with a further amber alert for Storm Conor now being issued for the far north of the country on Boxing Day.
Flood alerts are also in place for the Highlands and Western Isles as well as Skye and the Scottish Borders.
Brent Walker, Met Office deputy chief meteorologist, said: “Storm Barbara is crossing the Atlantic and will pass close to the north-west of the UK during Friday, bringing the potential for some disruption to power supplies and travel, and possibly structural damage.”
Pockets of Northern Ireland, north Wales and the north of England are also due to feel the force of the storm on Friday.
Scottish and Southern Electricity Networks (SSEN), which owns and operates the electricity distribution network in the north of Scotland, remain on yellow alert with 600 frontline and support staff on stand-by.
South of the border, councils were said to be ‘’fully prepared’’ for the onset of harsh conditions over Christmas.
The Local Government Association (LGA), which represents hundreds of councils in England and Wales, said it was issuing renewed advice on how to deal with flash floods and has stockpiled more than one million tonnes of salt to grit roads.
People can call 105, a free new national phone line, if the weather damages their local power network and affects electricity supply.
The number is available to people in England, Scotland and Wales, regardless of who they buy electricity from.