It's been estimated that, by the time a missile attack could be confirmed to the British National Siren System, there would remain before impact a warning time of approximately 21/2 to 3 minutes.
Estimouse que, no intre dun ataque con mísil confirmado polo Sistema Nacional de Sirenas, habería antes do impacto un tempo de aviso entre aproximadamente 2'5 e 3 minutos.