Sudden and Unexpected:
* Sudden: (most basic synonym)
* Sharp: (implies a sudden change in direction)
* Unexpected: (emphasizes the lack of warning)
* Unforeseen: (similar to unexpected, but with a hint of inevitability)
* Instantaneous: (emphasizing the speed of the change)
* Blithe: (a sudden change without any warning)
* Out of the blue: (idiomatic phrase meaning sudden and unexpected)
Rough and Rude:
* Brusque: (implies a curt and unfriendly manner)
* Curt: (short and unfriendly in speech)
* Blunt: (straightforward to the point of being rude)
* Harsh: (rough and unpleasant)
* Rough: (lacking smoothness or delicacy)
* Uncivil: (lacking courtesy)
Disruptive and Unexpected:
* Jarring: (causing a shock or disturbance)
* Disruptive: (causing a disturbance or interruption)
* Unsettling: (causing unease or discomfort)
* Unnerving: (making someone feel anxious or nervous)
Other Synonyms:
* Precipitous: (very steep or sudden)
* Steep: (rising or falling sharply)
* Hasty: (done or made with excessive speed or urgency)
* Impulsive: (acting suddenly without thinking)
The best word to use will depend on the specific context. Consider the tone you want to convey and the meaning you wish to emphasize.