The Met Office has issued a 17-hour yellow weather warning for rain tomorrow (Wednesday, September 17), with parts of Breconshire included in the alert.

The warning, in place from 6am until 11pm, covers the whole of the Swansea Valley - including Ystradgynlais - as well as a stretch of the A470 between Brecon and Merthyr.

Forecasters say heavy rain could bring travel delays and possible flooding in some areas.

A Met Office spokesperson said: “Rain will become persistent and at times heavy across south and southwest Wales during Wednesday morning and is likely to continue for much of the day. 30-40 mm of rain is expected to fall widely with some places, chiefly on south-west facing hills, receiving 50-70 mm.”

Drivers are being urged to take extra care on the roads, with surface water and spray likely to cause difficult conditions.