As a weather weenie - their attempt to program in pattern recognition is exactly how human weather forecasts work. The guys and gals at the met offices look at all the main models, particularly those that are more accurate for their areas, mix that with their experience, and then create a forecast based upon a combination. Any service that relies strictly on one model is never as accurate as one that mixes data with the raw processing power and pattern recognition capacity of a person. And no method will ever be totally accurate because we will never know all the variables and how they interact every time. Chaos is never an easy equation to import into any forecasting system.