Paul Knightley
EF5
Yes, we've even had a BBC documentary about this over here! I'm not sure whether they need a classification, personally - I think they are a type of undulatus. However, I've seen them quite frequently on the Plains, and sometimes over here. In fact, quite often if you look at rows of AcCas, the bases look rather like this, but less homogenous.
cdcollura
EF5
Good day all,
To me it just looks like outflow from a shower / thunderstorms (the clouds we see BEHIND the gust front).
I have a very similar pictures below...
Above: North of Kansas City, MO on the morning of June 8, 2009.
Above: A MUCH more dramatic version of the similar clouds, stirred by turbulence (don't fly through these), over Lakeland, FL in Spring 2005.
To me it just looks like outflow from a shower / thunderstorms (the clouds we see BEHIND the gust front).
I have a very similar pictures below...
Above: North of Kansas City, MO on the morning of June 8, 2009.
Above: A MUCH more dramatic version of the similar clouds, stirred by turbulence (don't fly through these), over Lakeland, FL in Spring 2005.
J.B. Dixon
EF2
Apparently a radio station DJ in Des Moines is steering listeners to a link of this on their website proclaiming that this woman in Cedar Rapids took pictures of a cloud formation "that hasn't been seen since 1951". LOL Close!
Tony Perkins
EF2
I've seen it a number of times too, usually in the morning (frontlit conditions?). Here's a less dramatic example of it.
John Massura
EF1
I think someone posted these pics here on ST awhile ago, they may be the same type.
http://www.dailymail.co.uk/sciencet...ifying-beauty-clouds-gathering-Greenland.html
http://www.dailymail.co.uk/sciencet...ifying-beauty-clouds-gathering-Greenland.html
Tim Shriver
EF4
SLC
Scary Looking Cloud
Tim
Scary Looking Cloud
Tim
Paul Hadfield
EF3
Anyone who thinks this is some new cloud phenomena hasn't spent much time looking up. This is outflow after a thunderstorm has completely collapsed and is spreading its cool entrails out across the lower atmosphere before significant daytime heating has had a chance to dissipate the remnants. It's not a cloud but rather a simple action of turbulence taking place underneath decaying cumulus/cumulonimbus clouds for which we see the base. It happens all the time and as I have seen, especially frequent in the AM when the low atmosphere is most cool and stable thus allowing for the cool air mass to ride across almost like a cold on cool inversion layer. Here's a time lapse...
http://www.dailymotion.com/video/x8i39j_june-13-2008-outflow-over-w-macon-c_tech
Edit: I don't think John Massura's link though dramatic is the same type. The first link shows precip in the distance, a clear giveaway IMO coupled with time of day (overhead light = AM/midday = cool lower atmosphere).
November 6, 2008 - Trailing off of a moisture starved CF
http://www.dailymotion.com/video/x8i39j_june-13-2008-outflow-over-w-macon-c_tech
Edit: I don't think John Massura's link though dramatic is the same type. The first link shows precip in the distance, a clear giveaway IMO coupled with time of day (overhead light = AM/midday = cool lower atmosphere).
November 6, 2008 - Trailing off of a moisture starved CF
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Brian Stertz
EF5
Someone needs to do their homework and get a clue in the media before publishing fluff what amounts to advective undulatus...I observed this several times in Tulsa when the boundary is south of the Red River across N. Texas. Not rare at all....that is a fact !!
D. Hayes
Question are these photos HDR? Like Christopher's second photo and the one on the OP's link. Both appear photoshop altered or high dynamic range photo's which is what I think is stirring everyone up. I've definitely seen outflow as everyone else posted but not so dramatic as the hyped up photos.
