These pictures were taken today in Oklahoma City and I am both baffled and curious as to what formation this may be. I was wondering if anyone had any idea?

unknown cloud 1

unknown cloud 2

Thank you!

  • 1
    $\begingroup$ About what time will help in sourcing radar and satellite data to match. You're talking about the wide arc, yes? $\endgroup$ Apr 27, 2018 at 4:18
  • $\begingroup$ It appears to me to possibly be either a gravity wave or an outflow boundary. As @JeopardyTempest indicated, satellite and radar data would help. If you don't know where to find that information, you could give us a date and approximate time and we may be able to. $\endgroup$
    – DavidH
    Apr 27, 2018 at 12:02

1 Answer 1


Well, after a bit of research, I stumbled upon the following image:

copyright Roger Edwards

This is from a blog of two storm chasers Roger and Elke who I believe witnessed the same cloud formation as you. In the following link:


They refer to the formation as a 'rear flank arc cloud'.

So in conclusion I believe, the formation is a kind of arcus cloud. You can learn more about arcus clouds on wikipedia by following the link:


I hope I have been of help.

  • $\begingroup$ Useful searching... but though it may or may not be an arc cloud, it does not appear to be associated with any storm structure such as would entail a rear-flank downdraft. Thanks for the input! $\endgroup$ May 10, 2018 at 23:31
  • 1
    $\begingroup$ @JeopardyTempest - to me it looks like a Arcus cloud - en.wikipedia.org/wiki/Arcus_cloud. $\endgroup$
    – user1066
    May 27, 2018 at 16:21
  • $\begingroup$ And these are common in gust fronts and they are sometimes known as shelf clouds. $\endgroup$
    – user1066
    May 27, 2018 at 16:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.