《黄帝内经·素问·本病论》
天空中赤色云气始见，黑色云气反常而发生，温暖的之气才欲发生，冷气又突然而至，甚至降下冰雹。
即彤云才见，黑气反生，暄暖欲生，冷气卒至，甚即冰雹也。
Red clouds begin to appear in the sky, black clouds appear abnormally, and warm air is about to occur, and cold air comes suddenly, and even hail falls.