THUNDERSTORMS, flash floods and torrential rain will drench Hampshire today as the heatwave goes out with a bang.

The rain is likely to bring cooler temperatures ending a 17-day stretch of temperatures hitting 28°C (82°F) and above and the longest heatwave since 2006.

The county has been put on a heavy rainfall alert as thunderstorms move in from the south east of England, which could lead to localised flooding and disrupt some train services.

The Met Office is expecting to see up to 30mm of rainfall today, which can be blamed on a cluster of wet air which has moved in from the Atlantic.

So far England has seen only 4mm of rain which is just six per cent of the expected rainfall for July.

The warm weather has made a change from 2012, which was the wettest year in the UK since records started in 1910.

Last year’s soggy summer saw two Red Arrows performances in Southampton cancelled for two major cruise events due to lashing rain and gales.

The city’s Mela festival at Hoglands Park was scrapped last July, the traditional three-day Netley Marsh steam rally could not go ahead because the ground was too damp and the Isle of Wight festival was a mud bath.

But don’t put away the sunscreen just yet as the sun is likely to return at the end of the week but with cooler temperatures than we have seen so far.

A spokeswoman from the Environment Agency said: “We have been out and prepared our structures in case of heavy downpours. We are keeping a very close eye on flood forecasting systems and are expecting some localised heavy rain.”

A spokesman for South West Trains – Network Rail Alliance – said: “Weather conditions can and do affect transport companies in various ways. It is part of our risk mitigation strategy to prepare for such occurrences but it is not linked to a specific event.

“We continually monitor the weather forecast to help us prepare for any adverse condition. As always we advise passengers to check our website or National Rail Enquiries before they travel.”

A spokeswoman from the Met Office said: “The change in the weather can be explained by an injection of wet Atlantic air above the UK, as the high pressure responsible for the heatwave dies away. When the wet air hits hot air from high above it causes stormy conditions.”