A month’s worth of rain could fall in 24hrs on Thursday, as up to 70mm of rain is forecast to fall across North Wales, with winds of up to 40 mph also forecast.
Heavy rain will start tonight and by the early hours, most of the rain will be confined to North Wales, with clear spells and blustery showers in the south.
Rain will persist across parts of North Wales during Thursday and the Met Office have issued a weather warning from 9am on Thursday to 11pm on Thursday night.
Heavy rain may lead to some disruption. There is a small chance that homes and businesses could be flooded, causing damage to some buildings.
In some areas there is a small chance of fast flowing or deep floodwater causing danger to life.
Where flooding occurs, there is a slight chance of delays or cancellations to train and bus services. Spray and flooding could lead to difficult driving conditions and some road closures.
There is a small chance that some communities become cut off by flooded roads and there is a slight chance of power cuts and loss of other services to some homes and businesses.
Friday will be mostly clear, with the odd shower expected during the morning. It will turn unsettled on Saturday with some heavy rain, however, this should have cleared by Sunday.