The Met Office has issued a heavy rain yellow weather warning for parts of south Wales.
The warning is in place between 8pm on Thursday and 2am on Friday.
Remnants of Storm Agnes could bring 50mm of rainfall over a few hours to parts of south Wales as the storm works its way out to sea.
Flooding is expected to occur which could lead to difficult driving conditions and a chance of delays to train and bus services.
Grahame Madge, a spokesperson for the Met Office, said: “There’s a couple of areas of low pressure, one to the far north west of the UK that will bring some quite lively rainfall to parts of Scotland.
“And another one out south west, which could well trigger concerns about the impacts of heavy rain in parts of south Wales.”
On Friday, temperatures may drop to single digits and more heavy rain is forecast on Saturday.
Storm Agnes hit the UK on Wednesday with gale force winds causing flight cancellations, flooding and power outages.
The first named storm of the season drummed up a high of 79mph winds in Capel Curig on Wednesday evening.
Elsewhere, winds were recorded reaching speeds of 68mph in Aberdaron.
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