Missing Cat Raheny

My Mother's cat went missing from Raheny, Dublin 5 yesterday. He went out at 5am yesterday morning and hasn't been seen since. He's a big cat but is very frightened which is why we are all so worried about him. He's mostly white with a tabby back. He has a Pink nose. He's only 1 and a half and we are devastated that he hasn't come home. Any help would be greatly appreciated. Many thanks.