The Inverse Law of Meteorological Prognostication. This states that the higher the chance of a weather event occurring, the lower the odds are that it actually will and vice versa. Simply put, if the forecast calls for an 80% chance of rain it will actually only rain 20% of the time but if the prediction is for a 10% chance of a weather event, watch out, you’re gonna get clobbered.
Works every time!