To answer a few questions:
The thought that a hurricane can get strong enough to change its surrounding environment to the extent that the changed environment can alter the track (or intensity) of the hurricane is now considered to be a myth by most tropical meteorologists - at least as far as the 'track change' capability goes. For intensity, a strong storm generates a stronger anticyclone aloft (because of the outflow) so a minor environmental increase in intensity is possible (with ocean heat content as the primary driver for intensification - or decay). In rare cases a Cat V Hurricane may seem to alter the environment, but in order for a tropical cyclone to attain Cat V, the environment cannot be hostile to begin with.

Now for the models. For the last couple of days, NHC has consistently stated in the Discussion bulletin that the east coast trough that cause a northward drift of Alex (and created shear that hindered the intensification process) would lift out to the north and east and that the western extention of the Atlantic ridge would redevelop over the northern Gulf of Mexico and curve Alex off to the northwest and eventually west northwest as that redevelopment occured. That process started last night and will continue today, tonight and tomorrow. There is nothing magical or complex about it - it is a very simple meteorological process. The models react based upon the data that is available for any given model run - and since that data varies, so does the model outputs from run-to-run. The models are guidance in determining the forecast, but they are not the forecast itself . NHC missed the last 24 hour forecast point for 29/12Z by about 25 miles - not too shabby at all.

The intensity models are also just guidance - and they are the least developed of the tropical forecasting tools - so they are often in error and NHC knows this.

Generally speaking, Alex is doing what NHC said it would do.
ED