Most weather forecasts people hear are generally short-term. This is because it is difficult to make a forecast beyond about 5 days when attempting to consider every little disturbance in the atmosphere. It is about 120 hours into the future when the mathmatical computations made by the typical computer models begin to make large errors. By about 10 days out, a forecast for a specific day is almost as good as going with the historical averages.

 

This is why it is important to know that there are long-term influences on our weather. These forces effect our weather not for a couple of days, but for months and years. In some cases, it has been shown that these forces can be predicted by using a different type of computer model, one that specifically considers only that one climatological influence.  Therefore, it is possible to make long-term forecasts by trying to predict these forces rather than using the traditional computer model projections. 

 

This section is designed to help explain some of these forces, more specifically telecommunication patterns. One of them, which most people have already heard of is the El Nino/ Southern Oscillation, also known as ENSO. But another force probably few have heard of before, the North Atlantic Oscillation or NAO also strongly affects weather in the Northeast, particularly our winters.