I see a “cone” on the NOAA National Hurricane Center site and on TV weather reports. What exactly is the “cone of uncertainty?
The “cone of uncertainty” shows the projected area through which the EYE OF THE STORM may track. The line, representing the projected track of the eye of the storm, may shift anywhere inside that cone; and, in fact, the eye of the storm may track along the perimeter of that cone. The NHC cautions against thinking of probabilities when viewing the cone; in other words, do NOT think that there is a lower probability for the eye of the storm to track along the perimeter of the cone than through the center of the cone. The cone reflects the average errors over 120 hours calculated at 12-hrs, 24-hrs, 36-hrs, 48-hrs, 72-hrs, 96-hrs and 120-hrs for the preceding 5 years (until March 2007 the average errors were calculated for the preceding 10 years). In other words, the cone reflects the National Hurricane Center’s success in predicting the path of the eye of the storm; 70% of their predictions for the path of the eye of the storm have fallen inside the cone (only 30% have tracked outside the
