20 category 4-5 per year since 1970? It is a big year if we have 20 per year of all categories, let alone 20 category 4-5.
It's a big deal that we're going to run out of names this year (21, they don't use a few letters) and have to go to Greek letters (Alpha, Beta...) -- and that includes all named storms. But I think that's just for ones that affect the US (could be wrong).
I presumed he was speaking of -all- typhoons, hurricanes, etc. world-wide. I suppose it's possible there are that many, though I don't know the exact figures.
"20 category 4-5 per year since 1970? It is a big year if we have 20 per year of all categories, let alone 20 category 4-5."
I shouldn't have paraphrased...
"While studies have not found an overall increase in tropical storms worldwide, the number of storms reaching categories 4 and 5 grew from about 11 per year in the 1970s to 18 per year since 1990, according to a report in Friday's issue of the journal Science."