Forewarn

Pro Tip 1/3

Nuanced Warning

Forewarn often implies a thoughtful, considerate warning about possible future problems.

I must forewarn you that the trail gets very treacherous beyond this point.

Pro Tip 2/3

Not Immediate Danger

'Forewarn' usually refers to future dangers, not ones that are immediate or already occurring.

The weather report forewarned of a powerful storm arriving next week.

Pro Tip 3/3

Serious Tone

Using 'forewarn' can carry a serious tone and suggest that the warning should be taken seriously.

I must forewarn you, the company's financial situation is more serious than you think.