surf's up
phraseEtymology Originally used in surfing to say there are good waves for surfing and one should get ready to ride them. This likely resulted in the later idiomatic use: to get ready for something.
1
A phrase used in surfing when a nearby wave is passing.
2
Idiomatic It's time (to do something).
- Yo, Harold! Surf's up! Those cars aren't going to wash themselves!