We set off many open-air nuclear bombs for many years, and no major climate change occurred. Keep the numbers in mind. A single hurricane shoves around the energy equivalent of 8,000 megatons, over 500 times the power of the Hiroshima bomb.

HAARP's eventual power output is listed at 3.7 million watts of radio frequency output. Hysterical conspiracy theorists have thrown numbers around as high as 10 billion watts. Even assuming this latter mythical number, if this entire power output was routed into the oceans, and NONE of it was re-radiated as heat (impossible), it would take almost 2,000 years of steady operation to raise the ocean temperature 1 degree. If you use the actual listed HAARP power level, this goes up to about 5 million years.

Relax.

This is one of those famous "if I fart, will there be a tidal wave?" concepts. We went through one of these on this board in excruciating detail with decaying radioactive particles.

A few more numbers for perspective: Approximate solar influx into the oceans = 5 x 10^15 watts, over 500,000 times the mythical 10 billion watt output of HAARP.

If there is any method of steering a hurricane, it would be done by applying a fraction of the hurricane's heat energy to nearby areas to urge it to move slightly one way or the other. Think tapping an elephant with a small stick to get it to turn. Even then, it is highly unlikely that you could make major changes in direction, since natural atmospheric flow would far outweigh your efforts.

It might be interesting to test on a circulating storm in the middle of the Pacific or something. But my instinct is that a largely stable chaotic system usually only gets worse if you mess with it. See also: economics.

P.S. If I dropped a decimal somewhere, let me know.