March 26, 2023

I was driving home after a week in Florida for spring break, taking turns doing shifts behind the wheel with my wife as we drove overnight after a full day at Disney World. We left the park at about 9:30 pm and were home in Illinois by 1:15 pm the next day.

We managed to dodge overnight supercells across Georgia.

Middle of the night, in bad terrain, with the whole family in tow, we weren't doing anything but driving away from these storms.

A relatively local event was shaping up in northern and eastern Illinois later in the day. Despite sleeping in the van on the way home, I was pretty exhausted from traveling, and yet I had the means and ability to maybe catch a “backyard surprise”. Backyard would of course translate to hundreds of miles driving around much of Illinois, but I figured I’d give it a shot instead of just sitting around at the house for the rest of the day. A surface low moving through the state with plenty of cold air aloft would set the stage for robust low level updrafts. I hoped that ample vorticity, low-level instability, and directional wind shear near the boundaries would make for low-topped rotating. My initial target was Morris, IL at 3-4pm, right on the warm front, given convective allow model guidance.

I grabbed a whole take-out veggie pizza, and was out the door. I drove northeast up I-55 toward developing showers, passing rows of layered updrafts before getting on a more robust cell at Dwight, IL. I exited and topped off at the truck stop, lingering to watch the base go overheard with some sporadic CG lightning.

There were some interesting patterns in the updraft base and downdraft interface, but I didn’t see much in the way of low-level rotation.

I tracked northeast with the cell up 55 for a ways until it crossed the interstate. I exited and went east as the cell back more whale’s mouthy and elevated looking. I let it go to track into the suburbs as an elevated hailer, making for more discrete, cellular activity coming up from the south.

High-contrast, low-topped convection:

Really robust convection tracking northeast near Gardner had my focus:

Despite the low tops, it was strong enough to push up pileus caps and exhibit knuckled structure.

I pulled over for this one, but I believe it was just a tiny hail shaft catching the setting sunlight.

Another pileus before the little cell started to weaken.

Pretty rain shaft catching the evening light:

I called the chase and headed for home.

A row of small cumulus had some interesting structure, as if the strong speed shear was blowing the tops off into tiny anvils, or perhaps a layer of stable air was causing a laminar band to trail the convection.