予よ告こくなしに

adverb

without advance notice; without warning

Used when something happens suddenly, without prior announcement or notification.

• 彼かれは予よ告こくなしに会かい社しゃを辞やめた。

  He quit the company without advance notice.

• 予よ告こくなしに停てい電でんが起おきた。

  A power outage occurred without warning.