The UK is braced for widespread weather disruption for the second weekend in a row as Storm Dennis barrels into the country.
Heavy rain and strong winds are expected from Saturday morning and are likely to affect transport links and trigger floods.
Wind speeds are forecast to reach 70mph along coastlines while some parts of the country could witness up to 120mm (4.7in) of rain.
Experts have warned that conditions amount to a "perfect storm" with hundreds of homes at risk of flooding. Cumbria, Lancashire and Yorkshire are likely to be worst affected.
#StormDennis has been rapidly developing overnight and will continue to deepen through today.
The central pressure is forecast to get near to 920 hectopascals (millibars) which is one of the lowest known pressures in the North Atlantic pic.twitter.com/e2nv6vswz6— Met Office (@metoffice)February 15, 2020
British Airways and easyJet have both confirmed cancellations, and anyone hoping to fly is advised to check their airline's website for the latest updates.
More than 230 easyJet flights in and out of the UK on Saturday have been cancelled due to the weather.
A spokesman for British Airways said: "The majority of our flights are planned to operate as planned, but, like all airlines flying to and from the UK today, we are experiencing some disruption due to the stormy weather conditions.
"We are merging a small number of Heathrow short-haul flights to the same destination and using larger aircraft where possible to minimise disruption.”
A spokeswoman for easyJet, which has confirmed 234 cancellations, said: "Due to forecasted adverse weather conditions caused by Storm Dennis, easyJet, like other airlines, is currently seeing disruption to its flight programme for Saturday February 15th.
"We are doing everything possible to minimise the impact of the disruption for our customers and to arrange alternative travel.”
Ryanair said all its flights are operating as normal.
Meanwhile troops are being deployed to help with preparations in the Calder Valley in West Yorkshire.
Calderdale Council said military personnel would also join workers and volunteers to support flood recovery efforts in the area, which was badly hit by flooding during Storm Ciara.
John Curtin, the executive director of flood and coastal risk management at the Environment Agency (EA), said the storm could inflict more damage than Ciara did last weekend.
The Met Office has issued eight weather warnings covering most of the UK over Saturday and Sunday.
This includes amber warnings from midday on Saturday over southern Scotland, northern England, Wales and part of the southwest saying that flooding could cause a danger to life.
Power cuts are also expected and there is a good chance train and buses will see cancellations or delays and roads closed.
More widely yellow warnings the length and breadth of the UK are alerting the public to strong winds and rain as early as 7am in Scotland on Saturday, with regions further south feeling the impact from around 10am or midday.
The EA said flooding is likely to be worse than under last weekend's Storm Ciara due to rain falling on already saturated ground.
In England alone, 800 properties were left flooded when Storm Ciara struck, the EA said.
Newly-appointed Environment Secretary George Eustice said authorities were "fully focused on ensuring that communities are protected".
The Met Office said the "main areas of concern" on Saturday are north and south-west England and Wales, with the South East bearing the brunt more on Sunday.
As of 11pm on Friday, there were 12 flood warnings, where flooding is "expected", and 141 flood alerts, where flooding is possible, in places across the country.
Flood defences are due to be in operation this weekend, with additional temporary flood barriers being installed in Shropshire, Lancashire, Yorkshire and Surrey.
More than 500 staff are on active incident duty and 30 mobile pumps have been deployed, the EA said.
Network Rail has advised passengers to expect disruption on many routes due to flooding and to allow more time for their journeys.
Meanwhile, people living near rail lines are being urged to secure any loose items in their gardens, after several trampolines were blown on to tracks and overhead electric wires last weekend, blocking lines.
The storm is also likely to cause treacherous driving conditions, with drivers urged not to attempt entering deep floodwater.
Additional reporting by PA Media