Okay, so storm surge may be pretty complex - although once the location is established, knowing what shore is relevant may still allow assessment. They gave predictions of how many feet from the storm surge before Florence hit the shore.
However, the weather forecast talked about the slowing of wind speed (hurricane category) as Florence was getting heavy from picking up water and talking about 40" of rainfall in some areas.
Here is the forecast from 9/12 and they seem very aware that this will be an especially bad storm from a flood standpoint as it was downgraded to Cat 2. I am making the case for a way to communicate that in a simple and direct fashion.
Perhaps the problem is we can evaluate the wind speed with good precision so the Category is a precise measure of the storm while the flooding potential may not be so precisely evaluated (?).
https://abcnews.go.com/US/hurricane-florence-slows-dramatically-approach-friday-night-landfall/story?id=57765962
The real issue, is how wide the storm is and how fast it moves when it makes landfall. There has to be some common sense in the public. I know this is not common. But you know the thing is full of water, and the speed after landfall was very accurately predicted. So a lot of water in the hurricane and slow movement means a lot of water in one place, versus the same water over a larger area in a faster moving storm. The same thing happened in Houston last year.
Now any hurricane is going to be over saturated with water. The global temperatures and oceans are warming on average. There is no debate about that, as you can easily measure it. Now that means unless there us sudden cooling all hurricanes are going to carry more water per cu. cm or by what ever yardstick you want to use.
So that means the water dumped over a given area is proportional to the area covered by the hurricane and how long it is over a given area. In other words it is inversely proportional to its speed of progression. I guess the solution is more formal education of the public.
I have to say the warnings in all aspects of the Florence event were highly accurate. So anybody taking a proper interest, which they certainly should, would have been duly forewarned.
Having lived through floods though I can tell you that home owners are almost universally ignorant of their elevation in relation to surrounding water. Everybody needs to be familiar with their local flood plain map.
As I mentioned in the other thread of Swerd's, these official maps are produced by the US Army Corps of Engineers. These are frequently out of date, but will tell you your elevation above significant bodies of water.
So if you know your elevation above a river or lake expected to leave its banks, and know your elevation you can work out if you will flood or not before or at any projected crest. This is an area were people and I might say city officials need more training. It is not difficult and I used these calculations to protect our neighborhood in the flood of 1997. The problem is the crest was not predicted accurately until far too late.
However along with a patient of mine, who was a civil engineer, we made some observations, and probably by luck rather than judgement made a very accurate prediction of the crest. I used our judgement for preparation as building chairman of our medical facilities and not the Corp or city officials to start primary protection measures early.
When I got our neighborhood together, and started our serious defenses only one resident did not take heed and got a flooded home. The city engineer even went on the radio to say my neighborhood preparations were not necessary. Then as we were evacuating the city a few days later he was diking his home in his edition, and I was pretty sure he did not need to and he didn't. As for us, our ring home dikes were just high enough. They were well built and did not fail or get topped, but the latter was close. I went to obsessional measures to protect and keep the neighbor hood road side power transformers dry. The power company did an inspection and agreed they would keep the power on as long as homes did not start to flood. This allowed home sump pumps to keep running in our area and we could use electric pumps on the dry side of the dikes for any under seepage, and not be dependent on gas pumps. We evacuated on the Saturday afternoon, as the city center was ablaze with the water too deep for the fire trucks to fight the blaze. The sky was full of helicopters plucking people of their roofs. We left two neighborhood volunteers behind to keep an eye on things. We did not have a a single fatality in the city though, which was very fortunate.
The Corps of course made blunder after blunder. They tried fruitlessly to do their defenses too close to the river, and did not protect the high ground. So when their defenses failed without backup protection on the high ground water quickly flowed over 85 to 90% of the city.
So knowing your elevation above problematic bodies of water is something all home owners and neighborhoods should know. That is job 1 when it comes to flooding, which unfortunately is far too common and takes home owners by surprise.
