What's the story about snow and thunder?

Snow and thunder have the following two sayings:

It thunders when it snows. Statement 1: It thunders on snowy days and graves and valleys pile up. Although snow and thunder are natural phenomena, they are relatively rare, so some folk sayings have been derived. For example, when it thunders in the first month, graves and valleys are very common, which means that if it snows and thunders in the first month, it means that the harvest is not good this year. In the past, people basically depended on the weather for food. If the weather is bad, the grain harvest will be reduced, and even some extreme weather will lead to extinction, so many people will starve to death and many graves will appear.

It thunders on snowy days. Folk saying 2: Thunder kills the cow. According to the folk saying, when it snows and thunders, the cow dies, which is very similar to the meaning of thunder and grave valley in the first month. One is a grave full of people who don't eat, and the other is that people don't have enough to eat because of the poor harvest, let alone give them food. If they don't eat, they will starve to death and die slowly. It seems exaggerated, but it is also a true portrayal. The cows are all skin and bones, and they can't even stand up. So many cows are starving to death, and the main beam of Niu Yi's dead family will fall down.