Heavy rain will lash Cardiff and much of South Wales from 3pm Wednesday until 6am Thursday, with the Met Office warning of flooding and travel disruption as 30-50mm of rain is expected to fall.
The yellow weather warning covers a swathe of South Wales from Carmarthenshire to Monmouthshire, with forecasters predicting some isolated areas could see even higher rainfall totals. Already saturated ground from recent wet weather heightens the flood risk, particularly in low-lying areas where drainage systems may struggle to cope.
Cardiff commuters face difficult driving conditions and potential delays on roads and public transport. The Met Office advises allowing extra time for journeys and checking flood alerts from Natural Resources Wales.
Similar rain warnings are in place for Devon and Cornwall, though Northern Ireland, Scotland and much of Northern England will see more settled conditions with cooler temperatures.
Wednesday's temperatures in Cardiff will reach 11-12°C before dropping to 7-8°C overnight, with moderate winds of 10-15mph gusting higher along exposed coastal areas. The combination of heavy rain and wind will make conditions particularly unpleasant outdoors.
Residents should avoid driving through floodwater and secure loose garden items ahead of stronger gusts. Those in flood-prone areas are advised to move valuables upstairs and prepare emergency kits. Pedestrians must exercise caution near swollen rivers and standing water.
The Met Office urges people to stay updated through official channels and local news throughout the warning period.