Coastal areas may experience gusts up to 80mph, posing risks of flying debris and large waves. The Met Office has issued yellow weather warnings for wind and rain in regions including Manchester, Sheffield, Liverpool, Bangor, St Davids, parts of north-east Scotland, and Northern Ireland.
The storm could lead to flooding, difficult travel conditions, power cuts, and disruptions to mobile phone coverage. There is a potential danger to life from the severe weather conditions.
Storm Debi will develop in the Republic of Ireland before sweeping over the UK, and is expected to move into the North Sea by Monday evening. This follows the disruptions caused by Storm Ciarán across the Channel Islands and southern England.