The Met Office has issued a yellow warning for thunderstorms across Northern Ireland on Tuesday afternoon.
They advised the warning will run up until 5pm and primarily covers Co Antrim and Co Down as the worst affected locations.
The warning says people can expect “intense thundery showers with some travel disruption and localised flooding possible”.
"Heavy thundery showers across the east of Northern Ireland will give some localised intense downpours,” said a Met Office spokesperson.
"Although many of these will be short lived, in places they may give 20 to 30mm in an hour or less, leading to some surface water flooding and disruption.
"The showers will merge with an area of more persistent rain moving east late this afternoon and loose their intensity.”
There is a particular warning to motorists to take extra care on the roads, with a good chance driving conditions will be affected by spray and standing water.
Delays to some train and bus services can also be expected. Earlier on Tuesday, the train service between Ballymena and Ballymoney was disrupted after lightning damaged equipment on the line.
Translink said the issue has since been resolved.
Meanwhile police advised the Lisburn Road in Belfast is currently blocked, due to a car stuck in floodwater.
They advised motorists to avoid the area and seek an alternative route if possible.
A police spokesperson said motorists should exercise caution due to heavy rainfall.