Strorm Surge?

[paul e]

The way I understand it, Storm surge is the 'mound' of water located within the eye, where, because of the relatively lower pressure, the height of the sea surface is considerably higher than that surrounding it. When the hurricane comes ashore, it deposits this central water mound onto the shoreline as surge, and a ways inland.

So, why would Ivan carry a cat 5 surge, when it had weekened to a cat 3? How long does it take the surge to respond to the rise in pressure?

[x-y-no]

No, storm surge is primarily caused by wind, only secondarily by low pressure.

Ivan's surge may have been somewhat larger than average for his strength for a number of reasons - his large size meant a longer fetch for his wind, the shape of the coast and the slope of the coastal plateau can enhance surge, and his prior history as a more powerful storm may have had some lingering effect in terms of how much surge he was carrying along.

[Sanibel]

Also, someone was arguing that they saw no physical outlet for Ivan's necessary kinetic energy, therefore he had to be at a high windspeed still.

The obvious answer is that this gigantic surge was the recipient of all this released energy as he weakened slightly...


A poster on another board said his Pensacola Beach house survived fairly well. The person who checked it out for him had his own house badly damaged. The lucky poster says he will probably move. The house checker said the surge mark was at the 12 foot level and that the intact house sat at 16 feet above sea-level...