Steve Gregory's blog on wunderground tropical weather is an easy read and very informative.

http://www.wunderground.com/blog/SteveGregory/show.html

I've cut and pasted from the latest. Not sure if this is in line with the forum guidelines (in spite of repeated posts by the mods) so if the mods want to edit that out and just leave the web addy, that is okey dokey by me.

"The latest Vortex RECON Report show Katrina has continued to intensify over night, but has just begun a temporary weakening cycle due to an eye wall replacement that began 3 hours ago with a pressure rise of 9mb to 949mb from early this AM. The CLOSED eye wall that was only 9NM across -- has just 'opened up' again to the NW, but has concentric eyewalls of 13NM and 40NM across. " ...

"That said -- the very same southwesterly winds that will initially aid in increasing the outflow channel ahead of the storm in the NNW quadrant, will also end up increasing the shears along the north Gulf coast just before Katrina reaches land. This will then, in spite of the extremely warm coastal waters of near 90deg -- lead to some weakening of the storm just prior to landfall. In some ways, a very similar situation to Dennis and last year, IVAN. One real 'memorable' difference between Hurricane Camille and IVAN, as probably Katrina, is that the storm headed for the coast around the western edge of a ridge line and came ashore prior to the arrival of an upper air TROF that would of produced some shears near the Gulf coast. Hence, Camille came in at full force. In this case, the ridge is first eroding away precisely because of the development of a major upper level TROF, and the shears will be increasing near the Gulf coast before Katrina makes landfall - as I've been expecting now for the past 2 days."

Exerpts are ok, but full reposts aren't, I respect other sites too. Weather Underground is ad/subscriber supported so out of respect I'll remove most of the article. Links are ok, the link for this is also at the bottom of the main page too. -- Mike C.