Barometers?

Question

Does stormy on a barometer mean snow or rain or does rain mean rain or snow thank you and also how far in advance can a barometer predict wheather

Answer 1

A barometer measures atmospheric pressure, and a good one will keep track of the trend. A downward slope in pressure means you're likely getting some sort of precipitation soon, or at least heavy cloud cover. It cannot predict the type. You need more data, such as temperature trends, to predict what kind of precipitation will occur.
So for a simple barometer that says "stormy" or "clear", "stormy" means you're probably going to get some sort of precipitation.