The Met Office has issued a yellow status thunderstorm weather warning for Northern Ireland.
The warning is valid between 7:00pm on Friday and 10:00am on Saturday.
"Heavy showers and some thunderstorms will develop over parts of Northern Ireland and southern Scotland on Friday evening before extending further northeast over Scotland overnight," said the Met Office.
"Heavy bursts of rain are expected, with hail also possible, giving accumulations of locally 15-30 mm within a few hours.
"The showers will move away from Northern Ireland in the early hours of Saturday then ease over Scotland later in the morning."
The Met Office warning applies to every county except Fermanagh.