Rare roll cloud over Alkmaar

I was lucky enough to observe a rare and wonderful phenomenon today, a roll cloud over Alkmaar, I have only ever seen pictures of these on the Internet or read about them.

 I took a couple of films, sorry about the quality, YouTube doesn't do it justice.

These clouds where actually unheard of until recently , you can't see in the film but it seemed to go on for miles and miles, one long tube, stretching into the horizon!

 

Related

http://www.thebigwobble.com/2010/01/roll-cloud-over-uruguay.html