They added a maximum of nearly three inches could pool as a result of the rain.
The Met Office said: “Heavy rain is expected to develop over parts of Wales during Wednesday afternoon and evening and then move gradually southwards during Wednesday night.
“This should then break up and clear during Thursday morning.
“20 to 30 mm rain is expected quite widely and in a few places between 50 and 70 mm rain could fall, the bulk of this within 6 hours.”
There is also a flood alert issued in the Gower penninsula.
The alert from The Natural Resources Wales reads: “The rainfall is forecast to ease by 5 AM on Thursday 11th June.
“The heaviest rainfall is expected to continue. The combination of ground conditions, existing river levels and forecast rainfall quantities gives a high risk of flooding of low-lying land overnight.”
Published at Thu, 11 Jun 2020 07:18:00 +0000