It looks like snow. 好像要下雪了。It looks like …句型是用来表达“看上去要…了。 ”
例如：It looks like rain. 要下雨了。
It looks like a wonderful day. 看起来是个不错的天气。

另外补充一下描述天气的形容词
clear “天气晴朗的” ，
cloudy “多云的”,
windy“风大的”,
sunny “阳光灿烂的”,
muggy “闷热的”,
boiling“炎热的”,
breezy “凉风吹拂的” ，
humid “潮湿的”,
freezing “冷得结冰的” 。
It'll probably clear up this afternoon. 下午天气可能会转晴。
Clear up是指天气由阴转晴。