Excellent question, Julie. I think it does have something to do with where the satellites are places and that sometimes fools our eyes...I've heard that more than once the last few days. I think a met could answer that question better than I can.
The NHC has been doing an excellent job with these storm tracks the last few years. I think it's because they have better technology. Also, they do not look at every wobble (like we do

) and make track changes until they see a trend in the models. They have also made a huge point in the last two or so years to tell us not to focus on the "black line"..which they do not use anymore. Atmospheric conditions can change and affect a storm .. like Gustav .. and that is why they have that cone.
I, personally, have much more faith now in the NHC track than I did a few years ago.