THE RELATIONSHIP BETWEEN MAXIMUM SURFACE WIND SPEEDS AND CENTRAL PRESSURE IN TROPICAL CYCLONES

The central surface pressure of a tropical cyclone has long been used as an indication of its intensity, There have been occurrences when un expected high (low) maximum surface wind speeds have been associated w ith relatively high (low) central surface pressures. In this study we have sought to identify situations when, on the basis of established e mpirical relationships, the central surface pressure of a tropical cyc lone misrepresents its maximum wind speed and show examples of cyclone s for which this is the case. It appears that the largest discrepancie s occur in the case of small or large tropical cyclones and in the cas e of fast-moving storms. We present simple theoretical arguments in su pport of these observations, which, to the extent that storms are axis ymmetric and in gradient-wind balance, are in line with elementary dyn amical considerations.