You are correct, I'm missing your point but that's no biggie. One of my favorite winds aloft tools for preflight, in case you're not familiar with it, is the RUC soundings (Skew-T Log-P diagrams) such as what's at
http://rucsoundings.noaa.gov/
There are also Android and iDevice apps that plot this information. In addition to winds aloft, you can see not just the cloud bases, but the tops and each cloud layer that is forecast, as well as the freezing levels, winds, dry and wet lapse rates, etc. all on the same diagram. It's very helpful to determine a flight level clear of clouds, cloud thicknesses, etc. and some models (my Android app) will let you advance thru time and watch what the clouds will do. There's a considerable learning curve to understand everything it's telling you, but you'll have the basics down within minutes. Unfortunately, the data is derrived from the same balloons that the FAA/NOAA uses, so the samples are widely scattered in distance and time and are therefore subject to much interpolation. In the example below, created just now from the link above, it's easy to see that Denver is (forecast to be) clear, because the temp/dew point (thick red and blue lines) never reach each other. The freezing level is about 7,000 ft, and the winds are relatively calm up to 6,000 ft and quickly pick up to 50kts at about 16,000 ft. Other lines depict lapse rate, etc. The Skew-T is a lot more usefuller than a simple high res winds aloft depiction, which the iFly servers download from a 3rd party source.
