The latest GFS track might actually be the best case scenario. Isaac would gradually weaken as it skimmed along the Louisiana coast, with the strongest wind affecting mostly coastal swampland. Then the extreme drought-stricken middle of the country would get a hugely beneficial tropical rain.

Moderator Note: The comment that Isaac would weaken in the latest GFS track is an assumption actually not made by that model. These last few GFS runs actually look like a horrible case scenario: large, major hurricane in the north-central GOM only slowly moving west-northwestward, with very little, or no weakening to speak of. These GFS runs suggest not hours, but potentially days of unrelenting storm surge, heavy rain and hurricane-force winds on the northern gulf coast. Variations on that general theme were in the 25/18z , 26/00z, 26/06z, and 26/12z runs, with no significant weakening indicated to speak of.

Ciel