A Comparison of Hurricane Steering Levels1

Using a grid system, geostrophic components are computed around tropical cyclones at the 700-, 500-, and 300-mb levels. These components are compared with the subsequent 24-hr motion of the cyclone. The 700- and 500-mb charts appear to be equally good in forecasting hurricane motion. Both are better than the 300-mb level. By combining the 700-mb geostrophic components with the motion of the cyclone during the previous 12 hr, a 24-hr forecast technique is developed. This combination appears to result in slightly better forecasts than from standard techniques now being applied at sea-level and at 500-mb.