The error cone is the area surrounding the track of a storm, or the area of potential threat. Reviewing the past five years’ forecasts, we have determined that 75% of the time, the center of a storm will track within the predetermined error cone. While this tells us how accurate our past forecasts have been, it does not tell us how much uncertainty there may be with a current storm. There is an unknown probability that a storm could move outside the error cone. Over time, with increased data and more accurate predictions, error cones have decreased in size, but this does not directly relate to storm size. Just because you are outside an error cone, does not mean you won’t be impacted by a storm.
To replace the Error Cone prediction, StormGeo has developed its own model called ‘Threatened Regions from Active Cyclones’ or TRAC. The TRAC guide looks at various predictive models and maps the expected track of a storm. TRAC allows for changes in a storm’s size and behavior, resulting in a more accurate prediction of areas at risk.