Mystery feature on KLSX radar - February 28, 2018

[Dan Robinson]

In the middle of the night on February 28, I saw this arcing band of rain showers on the KLSX (St. Louis) radar. What is the feature causing this? The mid and upper levels looked uniform and there were no apparent surface boundaries aligned in this way. There had not been upstream convection to create a remnant outflow. Light precip was streaming east from the stronger echoes along it. There was no lightning.

Other than a little bit of surface convergence apparent on the local obs, I can't figure out what this thing is.

 

[Jeff House]

Interesting feature, so sharp without much at the surface. Could have been WF as low as 925 mb or 850 mb. Seems too sharp to be farther up the mid-levels. Later that day of course low press developed in Kansas and moved through Missouri. I agree it's a strange feature for just WAA.

Meanwhile down here in Tennessee we broke our drought and went to flood control. Never a dull moment!

 

[Jeff Duda]

Whatever it was, it was very likely not to be a surface feature, and it probably was too small to be sampled by the radiosonde network. It is also beyond the purge date of GOES16 imagery that I can find.

 

[rdale]

Here's G16 - not that I see anything helpful

http://col.st/YwM9l