Pete...You are right, mainly the 850mb, 700mb and 500mb (mb = millibars) charts (Analysis and Forecast) give you an indication of where a Hurricane is going to go. However, sometimes with stronger storms such as Irma, most everything down to (actually up to) 100mb has to be taken into account. The problem with using any of the charts and data is the unknown factors that suddenly develop such as low pressure centers, tropical waves, high pressure ridges, erratic movement of fronts, unexpected Thunderstorm complexes that sometimes seem to develop out of no where or even the Hurricane itself which can create it's own large Mesoscale Environment due to it's sheer strength. The latter are the ones we really worry about or should I say, myself and others worried about when I worked at the National Weather Service Office in Key West as they pretty much can and will often move any direction they want.
Frank
