This is how the world ends: will we soon see category 6 hurricanes?
theguardian.com
theguardian.com
So "Cat 6" would serve no purpose unless it had some specific effect the general public needed to care about (Cat 5 already means "Oh for the love of root please GTFO you fools"). One thing that might actually affect it then is if there was a very wide general trend in construction of making buildings that were immune to some higher range of hurricane effects (say up to 170 mph). Then "Cat 6" could communicate a real different message to the public vs Cat 5.
Of course, as storms like this one demonstrate more broadly wind speed alone may be a very oversimplified measure, storm surge and rain accumulation are not necessarily correlated (wind speed also can cover a range of hurricane sizes). Whether and how to update scales for an era when we have global warming and vastly more sophisticated modeling is an area of real debate.
And while humans like to classify stuff, it may also be that scales like Saffir-Simpson are simply obsolete at this point. They come from the 70s, a time when public messaging was more broad based, more expensive, more bandwidth constrained, and had far lower resolution going into it. At this point it's debatable what value "classifying" tropical cyclones really has when the population can be provided with hourly (or higher) updates with predictions of a variety of impacts at ever higher spatial resolutions. I personally am not sure "Category $X" is what most people really pay attention to in a specific damage/risk-aversion since vs "what is the specific prediction at my house and surroundings over the next week".
so this is not well defined as with Earthquakes? So why not build a better clasification system?
I also suppose that their system is well defined...
I'm not sure what you mean by this. There are a lot of different seismic magnitude scales and seismic intensity scales, and they measure different things. Earthquakes are a fundamentally different kind of natural effect too, and in turn the goal and messaging involved with scales is different. Amongst other things, the temporal scale and foreknowledge is quite different and in turn what preparatory actions can be taken vary.
Saffir–Simpson is more of an intensity scale, and is well defined for its original design purpose. Whether that circumstances have evolved sufficiently that it needs to be updated or is simply irrelevant now is a different question.
http://articles.sun-sentinel.com/1997-09-10/news/9709090543_...