The UK is braced for heavy rain and snow as strong winds lash much of the country causing widespread flooding.
Heavy rain and snow is forecast north of the border on Thursday morning, with 2cm to 5cm likely for many parts and up to 20cm on the highest ground, the Met Office said.
A yellow "be aware" weather warning for snow kicked in just after midnight for the Scottish Highlands, Western Isles, Grampian, Strathclyde and Central, Tayside and Fife regions.
The warning, which covers the morning rush hour and is valid until 1pm on Thursday, warns that some roads and railways are likely to be affected, with possible longer journey times for road, bus and train services.
Meanwhile a yellow weather warning of heavy rain was in force for southern Scotland, northern England and Wales until 9am on Thursday.
Highways England closed the A14 in Suffolk in both directions between junction 56 and 57 and Lancaster City Council opened an emergency centre as a result of heavy rainfall.
Ireland was badly hit as flash floods wreaked significant damage in Mountmellick on Wednesday as torrents of water ran through the town and poured into multiple properties.
Laois County Council triggered an emergency plan, evacuating many residents to nearby hotels.
Civil Defence and Fire Service crews were involved in the relief efforts.
Forecasters warned that spray and flooding on roads will make journey times longer while bus and train services are also likely to be affected.
Strong winds were also forecast south of the border for the early hours of Thursday.
In Wales forecasters also warned of 70mph winds through Wednesday night as weather warnings continue.
The Met Office issued a yellow weather warning for the whole of Wales for Thursday.
On Wednesday night, several roads were closed in north Wales due to localised flooding and Plas Arthur Leisure centre in Llangefni was opened as a shelter for any person stranded due to the floods.
North Wales Police tweeted: "Our officers are dealing with numerous reports of localised flooding across our roads in Gwynedd and Anglesey this evening. Please avoid travelling where possible, essential travel only."
Officers based at Bangor and Bethesda reported severe flooding in parts of Caernarfon and Y Felinheli, while parts of Llangefni town centre were flooded after the River Cefni burst its banks.
Natural Resources Wales, meanwhile, issued 13 flood alerts which mainly applied to the north-west of the country.
Met Office spokeswoman Nicola Maxey said: "Snow is forecast for northern Scotland and this could potentially affect travel in the area.
"Outside that area snow is not going to be an issue, it's more likely to be heavy rain."
In the Highlands rail passengers faced disruption after three landslips following heavy rain forced the cancellation of some services.
Train services from Inverness to Kyle of Lochalsh and Wick were affected, with the line blocked between the Highland capital and Beauly.
The Scottish Environment Protection Agency (Sepa) has issued flood alerts for Dumfries and Galloway and the Borders.
South of the border there are a number of flood warnings in force, mostly in north west England, and dozens more flood alerts.
Sheena Engineer, national duty flood manager at the Environment Agency, added: "Heavy, persistent rain is expected across northern England on Wednesday and into Thursday. This brings of a risk of localised flooding, particularly across high ground in Cumbria.
"Environment Agency staff are out on the ground, checking flood defences and clearing debris from rivers. Preparations include installing a temporary barrier at Braithwaite, near Keswick.
"We will issue flood alerts and warnings where necessary. People should check their flood risk online and keep up to date with the latest situation at: https://flood-warning-information.service.gov.uk/."