The Met Office has issued another yellow weather warning for rain in Surrey and Hampshire on Thursday afternoon and evening.
A further spell of rain is expected to move northeast across southern and eastern parts of England on Thursday, clearing during Thursday night.
Forecasters warn more rain falling onto saturated ground may lead to further flooding and travel disruption across southern England.
A Met Office spokesman said: "The track of the heaviest rainfall remains a little uncertain, but 10-20 mm is likely to fall within six hours across much of the warning area, with some places seeing 30-40 mm; these higher accumulations more likely across central southern England.
"Impacts are more likely due to the current very wet ground across the region.
"Strong winds may also accompany this heavy rain across southern and particularly southeast England this evening and overnight."
There is a risk homes and businesses could be flooded, and delays or cancellations to train and bus services are possible.
Spray and flooding could lead to difficult driving conditions and some road closures, and some communities may be cut off by flooded roads.
Power cuts and loss of other services are possible.
The yellow warning is valid between midday on Thursday and 3am Friday.
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