Portend

[PussyCat]

To indicate (events, misfortunes, etc.) as in future;
to foreshow; to foretoken; to bode; -- now used esp. of unpropitious
signs.

[Kit]

to be a sign that something bad is likely to happen in the future:

[Monty]

Be a sign or warning that (something, especially something momentous or calamitous) is likely to happen.