Scattered thunderstorms and intense downpours could affect the Newark area tomorrow, according to the Met Office.
A yellow weather warning has been issued for rain between just after midnight tonight and 10pm tomorrow.
The Met Office says rain will move north across England and Wales in the early hours of Wednesday morning.
The thunderstorms could ease from the south later in the night, but further, possibly severe storms may break out again on Wednesday afternoon over northern England and northeast Wales.
The Met Office said although many places would miss the thunderstorms, there was a chance of some localised flooding of homes, businesses and roads.
Frequent lightning may be an additional hazard with potential disruption to power networks.