Thanks for the details. Can you explain the significance of an eyewall replacement, please?
Hurricanes go through cycles. At points the eye can no longer support the intensity of the hurricane and a second eye forms. Usually you can see the second eye, or the Cneter clouds over (eyewall collapses) -- but this is not always the case.
Anyway, as the eyewall replacement goes on the Hurricane loses intensity, sometimes a lot sometimes a little. Usually after the replacement the new eye allows for intensification of the storm.
Last night Katrina was at about 145 MPH when she went through an ERC, she emerged on the other side at 135 MPH, and then rapidly intesified to 175 through the night and the morning.
This afternoon it looked as if she had become annular (meaning she had reached a steady state), but over the last 6 hours she has weakened slightly. At first this looked like it might be interaction with a low over Texas or possibly theinflux of dry air as she neared the coast.
However it is now being theorized she may have been undergoing an ERC. If this is the case and she is coming out of the ERC with her intensity only going from 175 to 160, then we could see her start intensifying again over night. If this is the case we are now looking at a doomsday scenario. Her pressure is already stronger than Camille, and that is after a possible ERC.
On the other hand if it is from the influences of the other systems, then we could seeher continue to weaken slightly and come in as a CAT 4.
The next 3-6 hours will tell which is happening.
"Can you explain the significance of an eyewall replacement"
http://www.usatoday.com/weather/resources/askjack/2003-11-15-eyewall-replacement_x.htm