The phrase "bolt out of the blue" means something unexpected or surprising happening suddenly.
Sentences with «bolt out of the blue»
It was fascinating to hear Kate talk about her own writing process, and how sometimes events in her books occur to her like bolts out of the blue: «I was on a plane and I realized, oh my God,» she recalls. (bookpage.com)
«Like a lightning bolt out of the blue», Larry's wife Judith (Sari Lennick) announces that she is prepared to divorce Larry and wed widower Sy Ableman (Fred Melamed). (dvdizzy.com)
It's a lightning bolt out of the blue, the saddest thing in the world, and totally great, too. (4thletter.net)