Thunderstorm warning issued across Northern Ireland with flooding possible in places

A yellow weather warning is in force across Northern Ireland today as forecasters warn that intense thunderstorms could bring torrential downpours, lightning, hail and gusty winds.

The Met Office warning covers all six counties and is in place from 11am today, Thursday 13 August, until 6am on Friday.

While many places could escape the worst of the weather altogether, thunderstorms that do develop could produce 10–20mm of rain in less than an hour, with a chance of isolated locations receiving 20–30mm within an hour.

That intensity of rainfall could result in localised flooding, particularly where thunderstorms repeatedly affect the same area.

Warm and humid conditions fuel thunderstorms

The warning comes as Northern Ireland experiences another very warm and humid day, providing the conditions needed for scattered heavy showers and thunderstorms to develop.

The Met Office’s latest regional forecast describes Thursday as another “very warm” day, with variable cloud and some sunshine. Temperatures could reach 25°C, with sharp showers developing during the afternoon and a risk of hail and thunder.

The nature of thunderstorms means conditions could vary considerably over relatively short distances. Some communities may see little or no rain, while nearby areas could experience a sudden and intense downpour.

Heavy rain, lightning and hail possible

Where the strongest thunderstorms develop, the Met Office says heavy rain will not be the only hazard.

Lightning, hail and gusty winds are also possible, while the volume of rain falling over a short period could overwhelm drainage and cause flooding in places.

Conditions could become more widespread as Thursday progresses.

By the evening, individual showers and thunderstorms may begin to merge into longer spells of rain, with western parts of Northern Ireland particularly at risk.

The unsettled conditions could then continue through the night before the yellow warning expires at 6am on Friday 14 August.

People travelling or spending time outdoors today should keep an eye on the latest forecast and be prepared for conditions to deteriorate quickly if a thunderstorm develops nearby.

The warning does not mean every location will experience severe weather, but the scattered nature of the storms means some areas could see significant rainfall in a very short period while others remain largely dry.

The latest Northern Ireland forecast and weather warnings can be checked on the Met Office website.