That chart shows the loudness "at a determined flow rate and at a given distance from the receiver". That indicates to the chart is not showing the maximum volume, but rather a volume at a consistence flow rate for all the whistles tested for fairness. Again, that same site on top of that same page you linked claims 130 dB for the Storm.

When I just blew all three, the Storm definitely has a bit more beef in the volume. Again, however, it's a lower frequency and oscillating, which may or may not be better for a particular environment.

We are talking about categories of genius. All three whistles are extremely high performing. My preference came down to which one I would actually carry after the novelty of the whistles wore off.