out-of-the-blue

  • (r) in a way that was not expected
    • her brother showed up at the wedding out of the blue
    unexpectedly,
  • (s) not anticipated
    • "unanticipated and disconcerting lines of development"- H.W.Glidden
    • unforeseen circumstances
    • a virtue unlooked-for in people so full of energy
    • like a bolt out of the blue
    unanticipated, unforeseen, unlooked-for,

Synonyms

unexpectedly unanticipated unforeseen unlooked-for

Words of close approximity