they would wait for the royal family, government, secret service (i'm american so i don't know what you have for higher privileged people), and all the important people like them to get to the safest shelters, and THEN alert everyone else. Probably by broadcasting it over every TV station, radio station, and maybe even take over the internet to alert everyone.

the mushroom cloud would be a dead give-away

they wouldn't...all the royalty would get out and leave everyone else there

I'm not sure if they would.

Now answer mine please.

I am talking about the UK.

I was just wondering that since the decommission of the British National Siren system, UKWMO, the 4-minute warning and various other organizations and war plans that would be used to warn the public if there was a nuclear strike, how on earth would we be warned today? The government had a nation wide siren system that would warn everyone if there was an attack (but now almost all the sirens have been taken down), the UKWMO (UK warning and monitoring organization) would be used to track where nuclear devices had exploded and would track the fallout created by the explosions so fallout warnings could be issued and the public in different areas would know when fallout was present (but now UKWMO has been shut down). They would also have an all-clear alert that could be issued at different different in separate areas when fallout had passed. I really would like to know how the government would warn people if a nuclear war happened today. Thank you very much for any help :)