NOAA's National Weather Service is using a new hurricane scale called the Saffir-Simpson Hurricane Wind Scale. The scale keeps the same wind speed ranges as the original Saffir-Simpson Scale for each of the five hurricane categories, but no longer ties specific storm surge and flooding effects to each category. Changes were made to the Saffir-Simpson Scale because storm surge values and associated flooding are dependent on a combination of the storm's intensity, size, motion and barometric pressure, as well as the depth of the near-shore waters and local topographical features. As a result, storm surge values can be significantly outside the ranges suggested in the original scale.
For further information regarding the Saffir-Simpson Hurricane Wind Scale and other weather related information visit the the National Hurricane Center online.