This week has seen showers and thunderstorms in southern and eastern parts of England, with a persistent band of rain edging north and west as the week has continued.
During this evening heavy showers are expected to reach the Midlands, North Wales, northern England and southern Scotland.
In Wales, people are being advised not to travel unless it is essential.
North Wales Police tweeted: “Assess the need for your journey, drive to the conditions and your driving ability. Please DO NOT ignore any road closure signs. Think Safety.”
Transport for Wales tweeted: “Continued heavy rain during today means that travel to and from your desired destination cannot be guaranteed.”
National Rail has reported that heavy rain and flooding is affecting services in the North West including the Merseyrail service between Hamilton Square and Ellesmere Port and Chester, as well as Transport for Wales services between Aberystwyth, Chester, Crewe and Shrewsbury.
Virgin Trains between Llandudno Junction and Crewe and Chester have also been affected.
Overnight rain is expected to reach northeast Scotland through Wales to southwest England, clipping Irish coasts and extending into the Midlands with further warnings being issued for these areas into Thursday.