Question on Isabel

[koto26]

What is causing the constant knock down of convection on the west side of the storm, I haven't heard much said about shear at this time

[ColdFront77]

Hello koto. There has been some discussion about the shear affecting Isabel. There are a lot of threads and not too much mention about it because it isn't expecting to be a major issue with Hurricane Isabel.

[GalvestonDuck]

Here's one explanation maybe:

1: What is causing this weakening?
Many have commented that Isabel looks like it hit a brick wall, they said it in a joking manner however they were more or less right on the money.
http://orca.rsmas.miami.edu/wx/satellite/
If you take a look at an animated water vapor loop, BOOM you see Isabel stop immediately and begin to head more NW or even NNW. It quickly found the weakeness in the ridge and the turn was so sudden that it basically shocked the system and the west side caved in essentially. Also Isabel LOST its annular charecteristics as I mentioned yesterday and today it further shows that through the contracting even collapsing of the eye and the eyewall. The system also dealt with some minimal shear for quite some time, that broke up the western edge. There was also a blob of convection off the NC coast that put a major damper on the northern edge of Isabel.

From http://www.storm2k.org/phpbb2/viewtopic ... t=west+eye