A video of the clouds is available here.
According to the report:
"For reasons no one fully understands, noctilucent clouds tend to be most active during years of solar minimum. 2009 is such a year. The sun is in the pits of the deepest solar minimum in nearly a century, and many researchers expect a banner season for these mysterious clouds.
NLC OBSERVING TIPS: Look west 30 to 60 minutes after sunset when the Sun has dipped 6 to 16 degrees below the horizon: diagram. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud. Although noctilucent clouds appear most often at high latitudes, they have been sighted in recent years as far south as Colorado, Utah and Virginia."
For more awesome pictures of this phenomenon, visit the 2009 noctilucent cloud photo gallery.
I just love stuff like this!