... except that which you quoted from the linked article, I'd say its because they haven't got enough data.

The other intersting thing is the temporary nature of the effect. Note that, after reducing the wind speed by 30% it had increased again, so that two days later another 15% decrease was only able to bring them back down to "just under 100 mph".

So, say it was 99, and do the math: 99/x = (1.00 - 0.15); or 99 = 0.85x ; or 99/.085 = x

Rounding up, my calulator says x = 116.5 mph -- which is 1.5 mph faster than before the first reduction.

Nothing is said (beyond "five seedings at two hour intervals" for the first application) to indicate how much silver iodide was dispersed, nor how long they had to wait for a reduction in wind speed -- essentially from Category 3 to 1 the first time, and from 3 to 2 the second time.

Which brings us back to my ocean temperature map. Forcing more precipitation out of the cloud tops in one quadrant of the circle doesn't reduce the energy or moisture entering the entire circle from its lower surface.

In the lull between Katrina and Rita, REB recommended a book: Isaac's Storm, by Erik Larsen. I read it last week, and add my recommendation to REB's. Not only is it a well-told true story, but there's a lot of useful information about hurricane physics in it.

And, in case anyone was curious, this photograph from the article is of the wall cloud of a supercell thuderstorm, a formation land-bound storm chasers call a "mother ship". It's a scary piece of weather, no dispute -- it looks like it's ripe to drop multiple tornados -- but it's not a hurricane.