a bolt from the blue

US /ə boʊlt frəm ðə bluː/
UK /ə boʊlt frəm ðə bluː/
"a bolt from the blue" picture
1.

晴天霹靂, 意想不到的事件

a sudden, unexpected event that is usually unpleasant

:
The news of his resignation came as a bolt from the blue.
他辭職的消息猶如晴天霹靂
Her sudden illness was a bolt from the blue for the whole family.
她突然生病對全家人來說是晴天霹靂