A second is in place between midnight and 9pm on Sunday, covering Northern Ireland, Scotland, Wales and all of western England.
"Dangerous coastal conditions" are expected, the Met Office warned, with large waves an additional hazard.
Road, rail, air and ferry services in Scotland are all likely to be affected by the weather conditions, Transport Scotland said.
Get the five-day forecast where you are
Rebekah Hicks, Met Office deputy chief meteorologist, said: "This period of disruptive weather coincides with a busy period on UK roads as the festive getaway starts for many.
"The area of low pressure will bring rain and strong winds on Saturday, with a chance of significant disruption especially to transport networks across the north, including the potential for ferry cancellations.
"The strongest winds are expected across northern Scotland on Saturday afternoon and evening, with the potential for gusts of 80 to 85mph in coastal districts.
"The strong winds will be more widespread on Sunday with gusts of 50 to 60mph across much of northern, central and western UK, locally higher for coasts and across high ground."
It comes as drivers have been warned of a "pre-Christmas panic" on the roads and record levels of traffic.
Motorists have been urged not to travel on major routes for six hours on both Friday and Saturday to avoid the worst of the Christmas holiday traffic.
The RAC and transport analytics company Inrix said roads are likely to be busiest between 1pm and 7pm on those days.
Hotspots where queues are expected include the M3 between its junction with the M25 and the south coast, the M25 anticlockwise between its junctions with the M1 and the M23, and the M53 from Chester to Liverpool.
Will it be a white Christmas?
The wintry weather conditions are expected to turn more settled from the start of next week.
Winds will ease, but there will be further rain or drizzle moving east across the UK on Monday night, the Met Office said.
Christmas Eve will be a mild, blustery day with further rain or drizzle at times in the west and the best chance of sunny spells in the east.
It will be mostly cloudy and dry on Christmas Day, although strong winds and spells of rain are likely in the far north.
Temperatures are expected to be widely very mild, with the chance of settling snow looking slim.
1
2
3
4
.svg)
