forewarn about

forewarn (someone) about (something)

To inform someone of something in advance. Thanks for forewarning me about the boss's foul mood today—I made sure to steer clear of him.
See also: forewarn
Farlex Dictionary of Idioms.

forewarn someone about something

 and forewarn someone of something
to warn someone about someone or something. They forewarned us of your strange behavior. Didn't we forewarn you about Max's problem?
See also: forewarn
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • forewarn
  • forewarn (someone) about (something)
  • forewarn (someone) of (something)
  • be sick to death of (someone or something)
  • at risk to (someone, something, or oneself)
  • at risk to yourself/somebody/something
  • do (something) at (one's) own risk
  • do something at your own risk
  • be sick and tired of (something)
  • be tired to death of (something)
References in periodicals archive
Addressing a ceremony held here Thursday, Shakil Qadir said that United Nations Development Fund (UNDP) would provide 25 million dollars in case of natural catastrophe whereas Japan government would technically assist besides installing system that would forewarn about possible floods.
Foreign donors pledge financial, technical assistance in case of floods