How do you stop a hurricane? First look at Hawaii. They have been stopping them so well that it wasn't till the invention of satellites that people in Hawaii even knew the rainfall that week came from a hurricane that tried to strike but died .
To see how well Hawaii's tall volcanoes stop hurricanes see this list on Wikipedia.
http://en.wikipedia.org/wiki/List_of_Hawaii_hurricanes
Notice almost zero wind damage to all islands except one. Kauai is the last island in the chain and too far behind the big volcanoes to get protection. Only Kauai has seen hurricane force winds and everyone buying hurricane insurance on the other islands is probably wasting their money.
Hawaii's volcanoes do two things.
#1 They turn moisture into snow. Each pound of snow they make removes about 12,000 BTUs of energy. That isn't much compared to the trillions of BTU's of energy in a hurricane. However, Hawaii has hundreds of square miles of land above 9,000 feet elevation to make billions of lbs of snow.
#2 They also deflect large amounts of warm air high into the sky where it is ripped away by the jet stream and turned into ice crystals. In the video below you can watch a hurricane die right in front of Hawaii Island. Notice the large streaks of white that develop to the East. These clouds contain billions of lbs of water that were taken away from the hurricane.
http://www.youtube.com/watch?v=p_rxu0fJ2h8
Hawaii's system works so well that despite being in the middle of the Pacific, no hurricane winds have done any significant damage in at least 100 years to any islands except for Kauai.
So, there is now only a simple matter of copying Hawaii.
It would take too many dump truck loads of rocks to build big volcanoes in front of
Florida, and other places like New Orleans. However, the same jet stream also travels there too. One great thing is that the jet stream travels in the opposite direction as the hurricane. This means when you start pushing the jet stream down, the hurricane will run into all that cold dry air.
The collision of cold dry jet stream air and warm moist hurricane air makes cool damp air. Billions of lbs of the jet stream need to be deflected downward. However, cool damp air sinks. This means, that once you get the initial flow going, the cool damp air sinks and draws even more of the jet stream down.
Now I have a few ideas of my own.
How would you go about deflecting the jet stream down?
Philip Maise
Pahoa Hawaii