Storms near Rochelle, IL around 5:30PM tonight. There were a few observations that drew me to the location other than it already being my chase target. The first(featured image) was taken just north of the city. The yellow sign pointing at the shelf cloud approaching my location. The second is that same shelf cloud same storm looking north sceonds later. The rain core had the slightest greenish tint.
The last image was taken minutes later looking south at the southern most point of the t-storm complex. In a pretty good position here(not the safest though). What I call a nob cloud was is the location where you might expect a wall cloud. I call it a nob cloud because they occur all the time and not worthy of wall cloud status. Perhaps my assessment at the time was wrong and it was a wall cloud? Either way I was drawn in by a nice looking base above and east of it. What I noticed while processing the image was the smooth horizontal feature almost in the center of the picture. I interpreted this as the shelf cloud in the moment and it will remain as such, but kinda looks like a downburst? Anyway after this the storm engulfed me in series of technical and navigational failures. Really wish I had taken the time to get further south towards I-80 which was my go-no go line.
Nob clouds: I always keep my eyes on them but will usually already be looking for something else to chase.