A rain warning for has been issued for the south-east of the UK, which includes large parts of Powys.
The Met Office has issued the yellow warning for rain from 9pm tonight (Wednesday).
The warning runs for more than 24 hours - and is in place until 11:45pm tomorrow (Thursday).
The warning covers Brecon, Builth Wells, Crickhowell, Llanwrtyd Wells, Talgarth and Ystradgynlais - among other areas.
Llandovery in Carmarthenshire is also included in the warning area.
The forecaster says the heavy rain will becomes more extensive on Wednesday night and especially Thursday, with some flooding impacts expected.
“Not all areas will be affected, but scattered heavy showers on Wednesday night are expected to merge into longer spells of heavy, perhaps thundery rain overnight and through Thursday,” says the forecaster.
“Where heavy downpours occur, 20-40 mm are possible within an hour or two. Over a longer period a few places could see more than 50-60 mm, possibly even as much as 80 to 100 mm if repeated batches of heavy rain affect the same locations - this perhaps more likely during the second half of Thursday.”
A further yellow rain warning has also been issued for the entirety of Friday, covering southern areas of the county including Brecon, Crickhowell, Talgarth and Ystradgynlais.