For the last decade, since Hurricane Ike delivered a devastating storm surge into the greater Houston region, hurricane forecasters have wrung their hands about the efficacy of the Saffir-Simpson Hurricane Scale. Ike was designated a “Category 2” storm on the scale, which rates storms from 1 to 5. Categories 3, 4, and 5 are designated “major” hurricanes.
Because Ike was not a “major” hurricane, not everyone took the storm seriously. Eventually, after much debate, hurricane scientists decided that the Saffir-Simpson scale should only reference wind speed (and no longer storm surge), and that in its forecast products the National Hurricane Center would de-emphasize its use, and instead focus on the threats posed by any given storm—be it damaging winds, storm surge, or inland flooding from heavy rainfall.
The Saffir-Simpson scale was retained, however, because most Americans were familiar with it, and it remained a useful tool to very generally identify the threat level of any given storm. This was a compromise. Issuing warnings for hurricanes is a messy business, not least because the forecasts can and often do change, and because emergency managers desire a simple and clear message they can deliver to residents and business owners.
Source: Ars Technica – AccuWeather says it has created its own hurricane scale, but why?