A Met Office yellow thunderstorm warning is in effect for Northern Ireland from midday to 6pm on 30 June. The warning covers most of the country and warns of slow-moving thunderstorms that could bring localised flooding and travel disruption.

Forecasters said heavy showers and thunderstorms are expected to develop following overnight rain. Some areas could see 10-15mm of rain in under an hour, with totals reaching 25-30mm over two to three hours in the worst-affected locations. Hail and lightning are additional hazards.

The Met Office said driving conditions are likely to be affected by surface water and spray, leading to longer journey times. There is a chance of flooding to a few homes and businesses, possible damage from lightning strikes, and short-term power cuts. Train services may also face delays.

The public is advised to prepare a flood plan and an emergency kit if they live or work in areas prone to flash flooding. If caught outside during a thunderstorm, people should seek shelter in a safe enclosed space such as a car, avoid sheltering under trees, and move to lower ground if on high terrain.

The outlook for the rest of the day sees variable cloud with sunny spells between showers, and a maximum temperature of 20°C. Tonight will be largely cloudy with a risk of further showers and a low of 12°C. Tuesday is expected to start mainly dry before rain moves in during the afternoon, with freshening winds and a high of 18°C. From Wednesday to Friday, conditions are forecast to improve, becoming mainly dry and bright with occasional showers.