Seaworthy - July 2010

Ike’s path, to evacuate or not evacuate. Anecdotal evidence heavily suggests that some individuals may have made their decision according to the Saffir Simpson category, rather than the urgent warnings and forecasts from meteorologists and emergency management officials of a much more significant storm surge. In some cases, that proved to be fatal, as the surge reached as much as 15 to 20 feet, inundating a large section of the Texas coastline and killing over 20 people.

thing that can be done now is to begin expressing storm surge in terms of actual inundation, or maximum depth of water above ground level, rather than simply above normal tide levels. In addition to factoring in those local tide levels as well as topography, storm surge forecasts should now be much easier for most to understand and relate to.

The issue also goes beyond purely meteorological factors. The configuration of the ocean floor at the coastline plays a huge role in producing storm surge; a broad, gently sloping seafloor, such as the type present along much of the Gulf Coast, will generally produce much more surge than one that drops off sharply, as is found off the southeast Florida coast.

In the longer term, there is also work being done on eventual development of a specific Storm Surge Warning, which would allow more specific warning information tailored to individual areas along the coastline. Such a change would have impacts on the entire tropical cyclone watch/warning program, and is therefore probably at least a couple years away from implementation.

storm surge, as well as all other hurricane impacts, will only be as accurate as the forecasts of the hurricane itself, including size, motion and structure. In other words, a picture of potential storm surge inundation might depict very fine details, but it will only be correct if the storm's forecast size, motion and intensity are all totally accurate, which is seldom the case. There is great concern that such images, which imply a level of accuracy in the hurricane forecast that simply does not exist, could be taken far too literally, and cause people to make decisions based on an unrealistic graphic rather than the warnings and advice of their emergency managers.

The result of these findings has been the
removal of reference to Storm Surge in the
Saffir Simpson scale. While it is just not
feasible to produce a specific Storm Surge
scale due to the factors mentioned earlier,
the National Weather Service is working
with its emergency management and
media partners on ways to enhance storm
surge recognition and understanding. One
Conveying storm surge information to
users in a way that is both understandable
and realistic is also a challenge. On the
plus side, newer technologies, including
Geographic Information Systems (GIS) hold
great promise for allowing real time, highly
detailed graphics to depict storm surge
inundation, in many cases down to the level
of a city block. The downside is that while
such displays are visually striking, they belie
the fact that all forecasts and warnings of
In the end, for all the improvements being
made in hurricane forecasting, graphical
representation of storm surge and almost
instant communication, the ultimate
responsibility for our personal safety
does not rest with improved science or
technology. We must each be willing to
make proper preparations for a possible
hurricane strike, and to heed the warnings
and follow the advice of our emergency
management officials in order to make
the best possible decisions to protect
ourselves, our loved ones and our property
from what has been called “The Greatest
Storm On Earth,” the hurricane.