- a baleful look.
- a by-election at a time highly unpropitious for the Government.
- a dead and ominous silence prevailed.
- a sinister smile.
- forbidding thunderclouds.
- his threatening behavior.
- his tone became menacing.
- ill omens.
- ill predictions.
- my words with inauspicious thunderings shook heaven.
- ominous rumblings of discontent.
- sinister storm clouds.
- the situation became ugly.
- ugly black clouds.