Previous to much rain falling, the clouds grow bigger, and increase very fast, especially before thunder. When the clouds are formed like fleeces, but dense in the middle and bright towards the edges, with the sky bright, they are signs of a frost, with hail, snow, or rain. If clouds form high in air, in thin white trains like locks of wool, they portend wind, and probably rain. When a general cloudiness covers the sky, and small black fragments of clouds fly underneath, they are a sure sign of rain, and probably will be lasting. Two currents of clouds always portend rain, and, in summer, thunder.