Brendan Loy, a second-year law student at the University of Notre Dame, wrote in his blog, The Irish Trojan's Blog (which I linked to earlier) on August 26 at 1:57 p.m.:
At the risk of being alarmist, we could be 3-4 days away from an unprecedented cataclysm that could kill as many as 100,000 people in New Orleans. Such a scenario is unlikely -- the conditions would have be just right (or rather, just wrong) -- but IMHO, it's not nearly unlikely enough to feel good about things. If I were in New Orleans, I would seriously consider getting the hell out of dodge right now, just in case. Once the evacuation orders are issued, if it comes to that, it'll inevitably be an absolute madhouse, despite officials' best efforts. (More here.)
Later, at 11:22 p.m., he wrote:
"I'm not a meteorologist. I'm just an amateur weather enthusiast, a law-student blogger who happens to be a hurricane buff. But if I lived in New Orleans, I would definitely leave at this point. Tonight. Barring a major change in the forecast, I expect the evacuation orders to come tomorrow. That will produce massive traffic jams and general confusion. My advice? Beat the rush; get out now. For it is imperative to get out. Katrina probably won't destroy New Orleans -- but it could. So if anyone in New Orleans is reading this, I'd personally advise you to get the hell out of dodge."
Over the past few days, Loy's blog has been one of the best non-news-media sources of meteorological information on Hurricane Katrina. It's become one of the most popular blogs over the past week, having been linked to by blogosphere heavyweights like Glenn "Instapundit" Reynolds and Mickey "Kausfiles" Kaus. The past few days' entries on his blog are a fascinating transcript of Katrina's progress.

The New York Times has run a story on Loy and his blog: "Weather Nerd" in Indiana Warned New Orleans Mayor.