a sudden and entirely unforeseen event

Link to present incidents:
Donald Trump: Nigel Farage would be 'great' UK ambassador to US.
President-elect causes diplomatic upset, as Ukip leader (=Farage) says he is flattered by ‘bolt from the blue’ and Downing Street says there is no vacancy for key role. (The Guardian)
Ukip: right-wing populist political party in the United Kingdom