Oh, I had a good time with this one. Google "weather war" and immerse yourself in good old-fashioned cold war conspiracy theory. It seems that the Soviet Union (back when there was such a thing, also known as the "Evil Empire") set up a grid to manage the weather. It was known as the Woodpecker Grid, and was designed to affect the weather through EM impulses coming to us from the vacuum of space. Or something.

The Popular Mechanics article was pretty interesting and quite tame, by comparison.

The Woodpecker Grid was originally set up to manage the weather, and was never dismantled. Active after 50 years of inattention, it played a major part in Hurricane Katrina's strength and direction.

The conspiracy theorists post pictures of Hurricane Katrina, with arrows pointing to anomalies, little square areas of cloud which stand out from the rest of the swirling mass, looking like sheep dogs circling the panicked flock. Supposedly these local disturbances "herded" Katrina right on shore where it would do maximum damage.

Some people have too much time on their hands.