Thunderstorms and heavy rain may cause travel disruption across parts of southern England and Wales, the Met Office has forecast. The weather service has issued a yellow thunderstorm warning from 4pm to 11.59pm on Monday across much of south Wales, south-west England and parts of southern England. The Met Office said there was a “good chance” that driving conditions would be affected by spray, standing water or hail, and that train services could be delayed. It said flooding of a few homes and businesses was also possible, with damage to buildings and structures from lightning strikes, hail or gusty winds most likely close to coasts. Frank Saunders, a chief meteorologist at the Met Office, said: “Areas of heavy showers and thunderstorms will move northwards across southern parts of England and Wales later this afternoon before clearing northwards overnight. “It’s possible that some places could see 20-30mm of rain within two to three hours, with a small chance that a few places could receive 40mm. “Thunderstorms are most likely for south-facing coastal districts, and hail and some strong gusts of wind could accompany the heaviest showers and thunderstorms.” Further heavy showers and thunderstorms were expected across central and southern areas of the UK on Tuesday. A longer period of heavy rain was forecast over parts of south-east Scotland and north-east England later on Tuesday through to Wednesday. The Met Office said further weather warnings were possible until midweek as rain fell on already wet ground, but added that the risk of flooding should reduce. The weather service said it also had “increasing confidence” that ex-Hurricane Kirk would track to the south of the UK, bringing heavy rains and strong winds to northern France. Although north and south shifts remained possible, the threat of significant impacts to the UK from the ex-hurricane were now much reduced, it added. The Met Office said temperatures would decrease from Wednesday in the north, with all areas experiencing below average temperatures from Thursday. Night frosts were expected for some regions later in the week, and snow was possible for the higher mountains of Scotland.