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 unexpected high (low) maximum surface wind speeds have been associated with relatively high (low) central surface pressures. In this study we have sought to identify situations when, on the basis of established empirical relationships, the central surface pressure of a tropical cyclone misrepresents its maximum wind speed and show examples of cyclones for which this is the case. It appears that the largest discrepancies occur in the case of small or large tropical cyclones and in the case of fast-moving storms. We present simple theoretical arguments in support of these observations, which, to the extent that storms are axisymmetric and in gradient-wind balance, are in line with elementary dynamical considerations.