Heavy downpours threaten to bring flooding and disruption to parts of England, forecasters have said.
A yellow warning for rain covering the southwest has been extended and will now remain in force until the end of the day.
The Met Office said up to 25mm (1in) of rainfall is “expected quite widely” while this could rise to up to 60mm (2.4in) in places.
UK weather: The latest Sky News forecast
In addition to the possibility of power cuts, it added: “There is a chance that homes and businesses could be flooded, causing damage to some buildings.
“Spray and flooding is likely to lead to difficult driving conditions and some road closures.”
Persistent rain is also forecast for London and the southeast where a yellow rain warning running from 3pm on Sunday to 9am on Monday indicates widespread downpours.
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Rainfall of up to 25mm is forecast in many places – and could rise up to 40mm (1.6in) in parts.
The Met Office said: “With the ground already saturated this may lead to some flooding and disruption.”
As of lunchtime on Sunday, there were 54 flood warnings in place across the country and 168 alerts.
Met Office meteorologist Greg Dewhurst said: “We are keeping an eye on this area of low pressure as it moves into southern counties of England and Wales over the course of Sunday and into Monday.
“It will bring some heavy rain and some strong winds as well.”
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While temperatures are set to reach around 7C-9C (44-48F), it is likely to feel colder because of showers and strengthening wind.
Monday is looking largely fine, if windy, but the south east will be slow to dry up.