May 23, 2020

From my morning "chasecast" storm chasing forecast discussion:

"Day 1 Today:

Plains Target 1: "I'd like a chance for a tornado please". Stage in Cheyenne, go north to Goshen. NAM says the lid strength and 0-3km CAPE are open for business. CAMs consistently initiate supercells here.

Plains Target 2: "Cannot bust, need a safe bet". Sterling, CO. A big robust supercell is consistent plotted tracking up 76 into sw NE. Could be a nice easy chase with great structure, great photos. Tornado still possible.

Plains Target 3: "EF4 or GTFO" Hays, KS. Hope against the HRRR that you'll get initiation to the sw off the dryline bulge and a storm tracks into those backed winds as the LLJ ramps up. NAM NEST says it might happen. High risk of bust, high payout gamble could have you sitting on the highway under clear skies, watching an MCS roll in after dark, or maybe... just maybe a big fat stovepipe/barrel/wedge I dunno, but you didn't hear it here.

Plains Target 4: "I don't go north of 70 because I'm a lazy Southern Plains chaser". Hang out in Lubbock and watch the dryline erupt. CAMs show a big mixed mode line. Tornado possible, but thermos not super great. Could be an NST near initiation or a structure show.

Midwest Target: Weak warm front/Pacific Cold front triple point tracks from what looks like Cedar Rapids-Waterloo to Dubuque Iowa. I expect storms to initiate closer in on the low first. That's the bait. Don't take it. Then more storms off the cold front (which acts like a dryline here mind you). Get your storm where it bumps those backed winds in IL, weak warm front draped from Dubuque across Rochelle and into the sw suburbs/nw IN. Watch where your surface obs turn from southerly to southeast. Beteen I-80 and I-88. Dekalb might be a good staging point or Lasalle at 80 and 39. NW IL has ugly terrain avoid. Don't get into the suburbs too far or you'll just get hung up in traffic without a view, stay west of Joliet/Plainfield or south of 80. Expecting a tornado or two today."

Saturday, May 23 was my first chase with Jennifer Brindley Ubl of the season. The pandemic had made getting together with others a questionable practice, but by this point we were starting to get into the routine of watching our contacts and limiting our exposure with masks and avoiding public areas. This was a nice "backyard" setup to kick off the season, allowing for a late start and no overnight stay. Brindley brought vegan take out entrees for dinner. We met up in Rochelle, dropped a car, and then ran north and west.

Our first storm of the day we caught near the town of Leaf River. We were immediately greeted by what looked like a small cone funnel occluded behind the rear flank gust front. The storm almost immediately shrouded itself in rain, however, and we lost sight of it.

We stopped and shot high precipitation supercell structure for awhile before I decided we better bail and get on a discrete tornado warned cell to our southwest.

Tornado reports started to come in from our target storm. We raced to get down there, but had to plod our way through the small town speed limits and traffic in Polo. Finally clear of town and the last car, we were now straining to see over the gently rolling hills and groves in north central Illinois. And there it was, the object of our obsession, hanging behind a farmstead in the distance.

The funnel cloud wasn't fully condensed, but it was down enough that I'd personally count it as a tornado. Not a tiny rope, or point funnel that barely dips below the cloud base, these half way condensed trunks are almost always at least weak tornadoes. And indeed another chaser with a closer shot confirmed it with a light debris cloud at the surface.

As soon as we stopped with a great view to the west the tornado was done of course. It roped out just before we pulled over, but we were both able to get shots of it on our still and video cameras. A beefy wall cloud was still cranking away like a top, so we hoped the next cycle would quickly follow and we'd score another tube with a better, closer vantage this time.

We watched and shot time lapse of the wall cloud reorganizing for several minutes. The next tornado cycle never materialized, however.

We started stair stepping east and north as the storm transitioned. Coming in behind the rear flank gust front when I thought the storm was disorganized and between cycles, I put my face up to the window and looked straight up. A huge spiral cyclone was suspended above us in the clouds and moving off us to the north. We turned north to face the mass, Brindley not having seen it yet.

The swirling motion in the clouds was mesmerizing. The wind roared past us with a distinct rushing sound. Rotation in the base was tornadic and there was rapid rising motion on the southern end. Tornadogenesis seemed imminent. Yet there was no longer a tornado warning on the storm. Seeing the funnel in the distance was a rewarding catch, but the overhead spectacle of this cyclone, and being close enough to feel the storm's power was simply awesome.

We followed as closely as we could from the south as the circulation as it spun and cycled. At one point it looked like a large sculpted bowl funnel, lit up white in the clear air behind the storm to the west. However, it never condensed any further.

From my Facebook post of the event:

"And then there it was: A tornado in the distance, like hope on the horizon, a slender funnel, too shy to fully condense, roping out between the hills and trees of northwestern Illinois. A picture of a tornado is nice, but I need that immersive experience. I have to feel the storm, or hear the roar. That came next a short time later. The tornado warning had been dropped, and we were nosing in behind the RFD gust front when 9’oclock high there was a cinnabon swirl in the clouds. We turned onto the grid and nosed in right up to it. That swirl tightened up with some of the hardest low level rotation I’ve ever seen, inflow roaring into it. A carved out updraft tube emerged in the center, wrapped in sheaths of condensation, and rounded into a nice white bowl at the bottom as it spun away. We had front row, neck straining, Omnimax seats as the entire sky was a carousel of turquoise, white and steely grey revolving above our heads."

We chased the rotating updraft base through a few more cycles, each subsequent one a bit more disorganized than the last. We finally left it just shy of the Wisconsin border after the supercell had solidly transitioned into a high precipitation state. I wouldn't make it out of Illinois until the next month, the first May I hadn't chased out of state since 2006.

Brindley and I went after new development to the east. We caught an HP supercell at the edge of the far northwestern suburbs of Chicago. Our last attempt of the day resulted in prolific cloud to ground lightning barrages, rotating lowerings, and dramatic surges of mist moving through the foreground but no additional tornadoes.

Despite the tornado warnings, we let the HP storm go near the Huntley and Lake Crystal areass as it would just track into more and more densely populated areas.