High school geography. In the third set of pictures, cold and warm fronts is judged by the rain before the front and the rain after the front, but the positions of the rain in my picture are all the s

High school geography. In the third set of pictures, cold and warm fronts is judged by the rain before the front and the rain after the front, but the positions of the rain in my picture are all the same, all on that slope. I have taught geography for decades, but I don't seem to see such a representation in the third set of pictures in that book. What does this arrow stand for? Is the front moving in this direction? Wrong. Is the cold air moving in this direction? It's not right either.

The picture on the left is a cold front. It can be said that the moving direction of cold air at the cold front is forward. But the picture on the right is wrong. The moving direction of cold air under warm front is vortex. As long as you see cold air swirling under the front, you can judge that the front is a warm front, and the moving direction of the warm front is the moving direction of the warm air.

The exam won't be like this.

Work hard, son!