Warnings for wind and rain have come into effect as parts of the UK are hit by Storm Ashley.
Heavy rain and 80mph winds are predicted in places, with the first named storm of the season “likely” to bring a threat of injuries and danger to life, the Met Office has said.
A yellow warning for wind came into place for the entirety of Scotland and Northern Ireland and parts of north-west England and Wales at 3am and runs until midnight on Sunday.
Met Office meteorologist Dan Stroud said “very strong, severe gales” on Sunday coincide with high spring tides, which could also result in “very large waves”.
The north of Scotland will remain under a yellow warning for wind from midnight until 9am on Monday.
Further south, the Met Office has issued a yellow warning for the south-west of England and South Wales until midday on Sunday with a threat of disruption to travel with flooding and possible interruptions to power supplies.
Mr Stroud said strong, gale force winds are due to continue through to Monday morning, meaning “fallen debris and trees” could affect commuters at the start of the week.
Road users in Scotland have been advised to avoid unnecessary travel where possible, while Sunday’s annual Great South Run in Portsmouth, Hampshire, has been cancelled because of weather-related safety concerns.
Police Scotland have advised motorists to “plan ahead and avoid unnecessary travel where possible” ahead of the “strong likelihood” of disruption on roads, while Transport Scotland has warned of likely delays to public transport, including the country’s ferry network.
Chief Superintendent Hilary Sloan, Police Scotland’s head of road policing, said: “Make sure your vehicle has sufficient fuel and is completely roadworthy, with tyre pressure and tread meeting legal requirements.
“Ensure your mobile phone is fully charged in the event you need to call for assistance and if it is likely you may be within your vehicle for long periods of time, take additional clothing and water with you.”
Scot Rail said services will be subject to “precautionary speed restrictions” from 4pm on Sunday until Monday morning for services in the west and north Highlands, Ayrshire and Stranraer. The same restrictions will be introduced between Perth and Inverness from 6pm.
The company warned that services on Monday morning could be affected by trees and debris on the track and asked customers to check their services before travelling.
Ferry operator CalMac said many of its services on the west coast of Scotland had been cancelled for the day on Sunday with several others liable to be disrupted.
The Met Office said Sunday will be a “widely windy day” with storm-force wins in the north-west.
Rain will spread eastwards ahead of sunny spells, but with gusty winds moving east during the afternoon.
Meteorologist Ellie Glaisyer said: “Parts of western Scotland could see gusts of 70-80mph during the afternoon. It will turn drier and brighter across much of England and Wales with some sunny spells during the afternoon.”
Winds are expected to ease on Monday with rain moving into the south east. The north is expected to remaining blustery for much of the week.
The Environment Agency’s website listed 41 active flood warnings on Sunday morning, meaning flooding is expected, and 132 flood alerts, meaning flooding is possible.
The warnings include multiple areas of the River Severn, the south Cornwall coast and the Wye Estuary.
Natural Resources Wales said there are three flood warnings and 13 flood alerts in place, while 16 flood warnings have been issued by the Scottish Environment Protection Agency along with 17 alerts.