The Met Office has put a yellow alert in place from 7pm today until 3am tomorrow.
It has been issued for Portsmouth, Gosport, Havant, Fareham, Waterlooville, Hayling Island and the rest of Hampshire.
Residents are being warned that there is chance of ‘lightning strikes’ which could cause disruption.
On its website, the Met Office says: ‘Thunderstorms may bring disruption in some areas, especially to travel.
‘Spray and sudden flooding could lead to difficult driving conditions and some road closures
‘Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services, as well as possible power cuts
‘There is a small chance that homes and businesses could be flooded, with damage due to floodwater or lightning strikes.’
The forecaster adds: ‘Developing showers and thunderstorms are likely to intensify across parts of the warning area through the evening, before easing away eastwards after midnight.
‘Quite a lot of places will probably avoid the heaviest rain and thunder, but others could experience torrential downpours and frequent lightning, while large hail and strong wind gusts may also affect a few places.
‘Central parts of southern England are perhaps most likely to see impacts.
‘Rainfall amounts will be highly variable, as is usual in such situations, but the wettest spots perhaps seeing around 25 mm of rain inside an hour, and a possibility that somewhere could catch over 40 mm in 2 or 3 hours.’
Heavy rain is forecast in Portsmouth from 7pm through to midnight.