There are some patterns we look at to make weather predictions. First, when the wind speed is high we know it is likely that the weather will change. Second, when the barometer is below 30.00 in it is likely that there will be precipitation and when the barometer is above 30.00 in it is not likely there will be precipitation. Third, we know that stratus clouds or cumulonimbus clouds are the most likely to produce precipitation. Lastly we know that if we get precipitation with a temperature above 32 degrees we will likely have rain and when the temperature is below 32 degrees it is cold enough to have snow.
We look at data tables like these to see patterns in data.
In this graph I can see that the weather seems to change on Wednesday when the wind speeds up and the barometer drops. On Thursday the barometer drops still further, along with the temperature. Friday is probably the most likely day for precipitation and we would likely get snow because the temperature is below freezing.
In this graph I see that the weather stays stable through the whole week with high temperature, no clouds, and air pressure. Precipitation is not likely this week.