风云难测Unpredictable

大象对他的孩子们说：当东边阳光灿烂时，西边可能是狂风暴雨,你还不知道南方和北方的风云变化。世界风云变幻就是如此。没有谁能正确预测。

The elephant said to his children: When the sun is shining in the east, the west may be a storm, and you still don't know the changes in the south and north. This is the case with the changing world. No one can predict correctly.