(9/14/08 M. Wich) The video above was taken from my house in northern Colorado Springs, CO on September 11, 2008.  I found it interesting that I could see low level clouds moving across the sky, with the upper level clouds clearly not moving as fast (take a close look at the beginning of the clip).  The forecast for this day was for 12mph winds out of the north.  It's very unlikely that any of the area pilots would have considered this flyable weather (IT'S NOT!). 

After taking this video I captured some of the weather reports on the internet to see how close they came to predicting what I was seeing.  Overall the forecast were pretty good.  Take a look...
The chart above shows the forecasted winds aloft for 9AM on 9/11/08.  Clearly the winds are blowing much stronger at the lower altitudes (ground level in my neighborhood is around 6600ft).  On a typical (flyable) day, we like to see light winds at ground level with little wind speed increase at higher altitudes. This chart is almost upside down as compared to a more typical day.  I'm not a weather expert, so maybe someone can email me with some information about the significance of this (sungwich@msn.com).  Data for this chart came from blastvalve.com.
Above usairnet.com predicts 12mph winds at 9AM which is around the time the video was taken.
The chart above came from wunderground.com.  A weather station in my neighborhood recorded the morning's events.
Here's the surface map at 9AM over the Western U.S.  Map source is intellicast.com