Morning Glory Type Cloud in Germany

Introduction

In July ,17, 2009 I heard a short report in BR5 news  in my car radio about a rare cloud phenomena in  the south of Germany. Immediately I had a look at the Bayerischer Rundfunk website . I found an article named Seltene Wolke walzt über Bayern hinweg, I translate :

 "A Rare Cloud rolls over Bavaria
 Friday morning, 7:18 [MEST] : A thick, grey roll appears on the horizon of Munich and rolls in breathtaking speed over the town and forward over Bavaria.We asked our Meteorologist were this Roll Cloud came from, and what is so special with it.
....
The spetacular grey roll was a so called "Roll Cloud", we call it [in Germany] also "Böenwolke" or Wolkenwalze. It is typical for this type of cloud, that it seems to rotate about a horizontal axis, completely isolated from other clouds ( see Bayerischer Rundfunk picture ).
.......
Roll clouds develop out of a thunderstorm front like that  approaching Baden Wuerttemberg and Bavaria on Friday. When suddenly precipitaion begins in the original storm cloud the air masses are cooled so heavily that they descend . Thereby they lift the warm and humid air masses which approach the thunderstorm. A rolling motion occurs with extreme thermals and the cloud starts to roll "

Interestingly in a similar report   of the newspaper Muenchner Merkur  this cloud phenomena is called a  "Morning Glory" . I translate:

" A Rare Cloud rolls over Bavaria [!] 
A cloud fascinates Bavaria. On Friday morning a "Morning Glory" could be seen in he sky, a very rare Cloud phemomena, that is found mainly in Australia."

I was a bit surprised, that this event until now ( 22 July )was not treated in German weather forums or meteological websites in more detail. At least just when I wrote this I found this article Morning Glory in Wetter24 website dated 22.07.06:16.

So I decided to do some own research and by this occasion started my Clouds website, which has been planned for years.