© Matthew HorwoodWaves bashing the shore in Portcawl
The Met Office has issued an amber warning for wind - meaning disruption is likely - for much of the south coast of England and parts of Wales.
A gust of 106mph (170kmh) was recorded at The Needles, on the Isle of Wight.
Yellow warnings for rain are in place across much of the UK, as well as two "threat to life" flood alerts.
South Western Railway said heavy rain had "flooded the railway" between Bournemouth and Southampton, meaning cancellations and delays are possible until 10:00 GMT.
South Western, Southeastern Railway and the London Overground all reported fallen trees and other debris blocking lines and causing disruption in various locations. National Rail advised anyone travelling by train to check their journey before setting off.
Meanwhile, the ports of Dover and Calais warned Channel crossings were also being affected by the weather, with strong winds and poor visibility leading to a "risk of delays".
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Heavy rain has already caused flooding in Bedfordshire and Northamptonshire over the Christmas period.
Residents in 1,300 homes by the River Great Ouse in Bedfordshire were advised to move out following high water levels on Christmas Day.
Mayor of Bedford Borough Dave Hodgson told BBC Radio 5 Live that around 40 of those homes had gone on to receive flood damage.
He added that water levels in the area were "still high" on Sunday "but seem to be reducing at the moment".
Severe flood warnings remain in place in Northamptonshire for the River Nene, at Billing Aquadrome - where more than 1,000 people were evacuated on Christmas Day because of flooding - and at Cogenhoe Mill Caravan Site.
A further 88 flood warnings have been issued in England, six in Wales and 12 in Scotland.
Elsewhere, in Cirencester, Gloucestershire, council officials have been providing sandbags for those at risk of flooding due to heavy rain, after more than 70 homes were without power on Christmas Day when an electricity substation flooded.
And up to 40 homes were flooded on Christmas Eve in Witney, Oxfordshire, where the Environment Agency has warned that river levels are still rising.
The Met Office's amber weather warning for parts of Wales and the south coast of England says travel could be disrupted on Sunday morning.
It also warned that flying debris could cause injury or be a risk to life, and buildings could be damaged in the storm.
Further yellow weather warnings for wind and rain are in place across England, Wales, Northern Ireland and northern Scotland into Sunday, indicating 60mph winds are likely across the country.
Storm Bella is the second period of severe weather to be officially named by the UK's Met Office this winter.
Communities Secretary Robert Jenrick urged people to check official advice, including from the Environment Agency, which asked people to keep away from "swollen rivers and flooded land".
A statement on its website said: "It is often deeper than it looks and just 30cm of flowing water is enough to float your car."
Hope y'all are all OK. You do have interesting 'accents'.
R.C.