mtm4319 wrote:Operationally, this was a 75mph hurricane at 1002mb and a 35mph depression at 1000mb.
While it is a little odd, keep in mind that the minimum central pressure is not the best indicator of intensity. It's the pressure gradient that really matters, because ultimately this is what drives the horizontal wind. It's quite possible and even likely that the pressure gradient during the time when Ernesto was a hurricane was much tighter than it is now. The circulation was much smaller then. This can be confusing because central pressure is indeed sometimes used as a proxy to gauge the intensity of TC's, because it is so much easier to measure a point pressure value than it is to measure the pressure gradient, which requires many pressure readings at various locations around the storm center. Couple this with the fact that the pressure gradient only directly causes wind *acceleration*, while actual maximum wind speed is a function of many parameters, including the diameter of the eye, as well as still not well understood effects such as mesovortex formation, etc, and you have some idea how difficult it is to actually define and measure TC intensity.
