Both words seem to have a meaning of "current" and "tendency/trend". How are these different? Also, using the tendency meaning, do they differ from 傾向?
- 風潮 is "how people tend to think/feel about something these days". It can often be undesirable to the speaker, and it often has a negative or sarcastic nuance as compared to トレンド.
- 潮流 ("tide") is a fairly grandiose word as compared to 風潮, and it refers to a global and gradual movement, often toward a new paradigm, a new age, a new political system, etc.
- 傾向 is just "tendency", and it's typically unrelated to people's thoughts or ideology.
潮流 also has a physical meaning ("tide"). 風潮 is almost never used in a physical sense today.