Ike's a real turner

Since last Thursday, the long-range forecasts for Hurricane Ike, in chronological order, have included the following:

* It’s gonna curve north from Cuba and ram directly into south Florida.
* It’s gonna miss Florida, though perhaps deliver a glancing blow to the Keys, and ultimately smack the New Orleans portion of Louisiana.
* Louisiana is out of the woods. It probably will hit Texas.
* It’s gonna hit New Orleans directly.
* It’s gonna miss New Orleans by hundreds of miles and hit Texas.

Tell me again why long-range forecasts even exist?