The official alert, which came with a loud siren-like sound, warned people to stay indoors and was sent to every compatible mobile phone in the areas impacted by Storm Darragh.
On Friday the UK's weather forecasters, the Met Office, issued a red weather warning — the most serious type. Thousands of homes, many in Northern Ireland, Wales and western England, were left without power overnight.
Major highways and bridges across the country were closed because of strong winds, and multiple train services were suspended.
In Ireland, almost 400,000 homes, farms or businesses were without power as a result of the storm. Some flights at Dublin Airport were cancelled.