Question: What causes striations in some shelf clouds?

[Karla Dorman]

June 19, 2008, Burleson, Texas: Shelf Cloud (Images (c) 2008, Karla Dorman)

What causes the striations in the cloud formation? Wind shear? Diffluence of air? One of the strangest things I've ever seen.

Thank you in advance for answering my question.

 

[Mike Krzywonski]

Nice pics! Here is the link to a related thread:http://www.stormtrack.org/forum/showthread.php?t=14920

 

[Karla Dorman]

Thanks, Mike, for the link and the compliment on my pics. Just starting to PorchChase (no car, have cane, will travel). LOL Appreciate it!

 

[Laura Duchesne]

I was told that striations or banding in shelf clouds on outflow dominant storms were caused by shock waves from the outflow winds.... I don't know if this is really correct or not but the theory seems interesting.

 

[Christel Danning]

Are these also striations?

I took several pictures yesterday of the system that came through. I had never seen clouds perform this way - I am sure they have somewhere, sometime, but not here. Are these striations? If not, what causes clouds to perform like this? (I have been having trouble uploading the photos, will try in another post). Did anyone else take photos from yesterday?

Others I have spoken to (in FW and Dallas when the storms came over them) also claimed they had never seen the like. I would greatly appreciate any education that can be shared - Thanks!

 

[Christel Danning]

I took several pictures yesterday of the system that came through. I had never seen clouds perform this way - I am sure they have somewhere, sometime, but not here. Are these striations? If not, what causes clouds to perform like this? (I have been having trouble uploading the photos, will try in another post). Did anyone else take photos from yesterday?

Others I have spoken to (in FW and Dallas when the storms came over them) also claimed they had never seen the like. I would greatly appreciate any education that can be shared - Thanks!

I have the pix: the first is a distance shot, the other two are closeups... What causes this?

 

[Mike Deep]

Pretty sure that's altostratus undulatus or "wave clouds." I have less a pronounced photo here. See:
http://www.erh.noaa.gov/er/iln/Gallery/Clouds/clouds16.html
http://www.stormeyes.org/tornado/SkyPix/asundula.htm

 

[Christel Danning]

Thank you! I greatly appreciate it.

 

[Maurice Fitzgerald]

Yep, that's exactly what we had overhead yesterday in the DFW area. I was kicking myself for not having a camera as the sky not only looked beautiful due to this but almost otherworldly.