NOAA National Hurricane Center, Ike 5-Day Forecast Cone, USA, 11.12.2008 - 11.16.2008

The NHC official 3/5 day forecast cone of uncertainty in shapefile format is an experimental products that the National Hurricane Center is testing during the 2008 hurricane season.

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. Based on forecasts over the previous 5 years, the entire track of a tropical cyclone can be expected to remain within the cone roughly 60-70% of the time. It is important to note that the area affected by a tropical cyclone can extend well beyond the confines of the cone enclosing the most likely track area of the center.