Did we learn nothing from Independence Day? Nuking things for nuking's sake just doesn't work like we think it might. Take a hurricane, for example. It'd be relatively immune to whatever ordinance Bill Pullman—sorry, humanity—might throw at it.
First of all there'd be the obvious nuclear fallout. Because hurricanes are coziest in the tradewinds, NOAA says all that residual awfulness would spread quickly and efficiently to areas well outside the hurricane's predicted cone of travel. Firing a nuke into Irene would have likely made that minor hurricane into a beast more formidable than Isabel or Katrina, which at a Category 5 was the worst of the worst.
But what of the physics? Say we were immune to fallout and could lob nukes into storms to our heart's content. Would they do anything to a storm?
Again, NOAA is less than optimistic about our chances. As a species we're just too damn weak:
A fully developed hurricane can release heat energy at a rate of 5 to 20x1013 watts and converts less than 10% of the heat into the mechanical energy of the wind. The heat release is equivalent to a 10-megaton nuclear bomb exploding every 20 minutes. According to the 1993 World Almanac, the entire human race used energy at a rate of 1013 watts in 1990, a rate less than 20% of the power of a hurricane.
But Jack! Something, something shock waves! I read about those once and how they can be deceptively deadly!
Well, yes, you're right my little pyro, but when it comes to hurricanes those shockwaves still wouldn't be powerful enough to downgrade a hurricane from Cat5 to Cat 2:
[A shock wave] doesn't raise the barometric pressure after the shock has passed because barometric pressure in the atmosphere reflects the weight of the air above the ground. For normal atmospheric pressure, there are about ten metric tons (1000 kilograms per ton) of air bearing down on each square meter of surface. In the strongest hurricanes there are nine. To change a Category 5 hurricane into a Category 2 hurricane you would have to add about a half ton of air for each square meter inside the eye, or a total of a bit more than half a billion (500,000,000) tons for a 20 km radius eye.
And don't think we could preempt a hurricane by targeting its tropical storm/depression beginnings. Even if such a storm used 10% of the energy of a hurricane, that's still an incredible amount of energy. Besides, there are far too many storms and depressions that develop each year for such a strategy to be practical anyway. [NOAA via Matt Yglesias]