The Hurricane Center has been using the Saffir-Simpson categories 1 through 5 scale, which is based on a storm’s fastest wind speed, to quickly summarize hurricane strength since 1963.
Many residents of hurricane-prone areas use a storm’s category to decide whether to evacuate. Unfortunately, this has led many to make evacuation decisions that left them struggling for life in debris-filled water with many dying after surge destroyed their homes, which they had thought would be safe shelters. In addition, a hurricane’s wind speed doesn’t always correlate well with its surge, which is the high water a storm pushes ashore as it moves over land.
A relatively weak, but large hurricane can push more surge inland than a stronger, but smaller hurricane.
Since a storm’s surge doesn’t always arrive at the same time as its strongest winds, the surge watches and warnings will say when surge is expected.
The Hurricane Center and others have been working for the last few years to find ways to better alert those threatened by storm surge from relatively “weak” hurricanes while at the same time avoid making forecasts and warnings confusingly complex.
The Hurricane Center had previously announced that during this year’s June 1-November 30 season it will produce maps showing potential surge depths above ground level.
In the past, surge figures were for height above a fixed level based on mean sea level. Since many people don’t know the elevations of their neighborhoods above sea level, such surge projections meant little to them.