There is the continued risk of coastal flooding due to high seas.
Wind speeds hit 76mph on the Isles of Scilly as Storm Callum blew in during the early hours of Friday.
Paul Hand of ESB Networks said 30,000 homes and business were without power, but he anticipated this figure increasing as the storm moves north.
638 homes were without power on Friday as Electricity North West dealt with four power cuts across Cumbria, of which 549 were near Penrith.
The west of Britain was heaviest hit by the rains, with parts of south-Wales worst affected as rivers burst their banks and homes were left without power.
Other regions of the United Kingdom were expected to remain largely dry, but strong winds were forecast.More news: Fabinho: Klopp has a different style that I’m used to
"South Wales in particular is a cause for concern, with an amber warning in force", Met Office meteorologist Aidan McGivern warned.
Met Éireann also shared this footage taken by Ireland's Marine Institute, which is only a few meters away from their weather station in Ballymullet.
A yellow weather warning is in place in those areas - and parts of northern and south western England as well as some of Scotland - while a higher amber alert is in force for Wales.
The rain will continue from today into Saturday with over 100mm expected in places.
The forecaster says Friday will see Storm Callum causing further severe and locally damaging wind gusts to parts of the northwest today but winds will gradually moderate elsewhere.
The south-east is expected to be blustery but stay "quite dry", with temperatures possibly reaching up to 24C (75F).