What is this?

[kevin-palmer]

On Sunday I was in Galesburg, IL to photograph a squall line moving through. After it passed, I drove east to get ahead of it again. I was about to stop to take pictures of the photogenic whales mouth, when I noticed an interesting looking appendage on radar. It was at the very southern end of the line. Since it was close, I went to check it out. After a little while, the radar seemed to be showing rotation, but in a clockwise direction (anticylconic?).

Radar 1
Radar 2

From several miles away I saw what appeared to be an inflow tail. But I could not identify any other supercell features such as a wall cloud, rfd, or a low cloud base. It seems like I was close enough to be able to see whatever was there. Rain wasn't an issue although it was a bit hazy. I continued to follow the storm until it weakened and gusted out. I have a few questions about what I was looking at. I know tornadoes can form from kinks in squall lines. But is it possible for them to form at the very end of a line? Why was the rotation clockwise on radar? The radar site was about 70 miles away so the rotation might have only been in the upper level of the storm. Is that why I didn't see anything visually?

 

[Paul Knightley]

Hi Kevin - it's not always easy to be able to identify something from radar alone - do you have any pics?

The radar presentation suggests a linear feature to me - I don't really see any concentrated areas of rotation on the radar imagery, more of a linear gust front. Others may have a different view, of course.

 

[kevin-palmer]

I know that radar scan shows 2 green blobs, but most of the time only the lower one was showing. That's the one I was watching and thought it looked like some type of mesocyclone.

This picture was taken 6 minutes after the radar screenshots. Is that an inflow tail on the left?


Inflow Tail by kevin-palmer, on Flickr

When I got closer to the storm this is what it looked like. At this point it had started to weaken and soon gusted out.


End of the Line by kevin-palmer, on Flickr

Both panoramas were taken from east of the storm.

 

[Jeff Duda]

Inflow tails, at least the type associated with supercell storms, primarily are found to the east or northeast (or just downstream or downshear) of the updraft region of a supercell. Therefore, from the typical POV in the US from eastward moving storms, you would not see an inflow tail on the left side of a storm. You would tend to see it towards the right of the cloud base or overhead. Looking at your pictures and radar, I don't see any obvious supercell structure in there. There may have been enough shear in this case to try to generate supercell looking structure, but that certainly is more of a squall line morphology than a supercell morphology. I see from the velocity image that there may have been transient supercell structure, but you did not capture any in your images.

 

[Paul Knightley]

It looks more like an outflow-dominant cell - even so, if the flow at the level of that cloud was from the left/south, then you can see mid-level inflow feeders into cells, even within a more linear feature.

 

[kevin-palmer]

Thanks for the replies. Maybe I'm so anxious to see a supercell this year, that I was seeing things that weren't really there. Hopefully we get some good storms in Illinois next week.

 

[chrisbray]

kevin, I'm right there with you, I will be out and about next week, hopefully right here in Illinois!