Morrison, IL Chase Summary

May 9, 1995

By Gilbert Sebenste

I was eagerly anticipating Tuesday morning. As I arrived for work at 4 AM, it was even clearer why. An upper level low with vort maxes and short waves in southwest IA were rotating around the main center like a merry go round. Last night, before dusk, it had produced a couple of tornadoes in Nebraska and Iowa. As I looked at the charts at 0Z and then at 12Z later that morning, I knew today was a "go" for a chase!

Problem was, I had been sick Monday and Tuesday, and I knew I had a lot of things to do that afternoon after I got off work. But I knew I could do it quick, so I forecasted in earnest. Here's what I came up with:

The upper level low and it's short waves/upper level disturbances were to move across IA that afternoon. 500 MB level temps were near -20C. With a surface temp of 75F, the atmosphere would be unstable as all heck. The LI's were forecast to drop to -8 by the forecast models, and assuming it would get up to 75, that was logical. I wondered how soon the storms would form, if they would reach that potential.

Next was wind shear. Central IL? Had a short wave going through it that afternoon, yes, but no surface boundary to converge on until late. The cold front would not hit until later. But with the instability that would no doubt be in place...ahhhh, they'll get storms, nothing too bad. Maybe a funnel or two. Hmm. The Lincoln, IL (ILX) sounding looked like a "loaded gun", but helicity wasn't great. Upper level winds would be from the south...maybe southeast with convergence along the front, but after dark? and 30 degrees of shear? Nahhhhh.

Then where else? The obvious. In eastern IA, near the cold core of the low, where it happened the day before. Now, you had a surface warm front lying across northern IL and eastern IA, a focal point for surface winds. Plus, winds were southeasterly at the surface. With SW winds aloft, that's 60 degrees of low level shear, according to the sounding! Davenport, IA (DVN)'s raob looked great for wind shear. With cold air advection at 500 MB (temps 24 hours previous at 500 MB dropped 5 degrees C, and were progged to drop 2-3 more by evening!). Plus, an 80 knot jet stream overhead providing speed shear. What could go wrong?

Oh, yeah, that stuff I had to catch up on that afternoon. But, I managed to get done by 2:30 PM. But I had lost time. I went to the NIU weather office. The clouds had just started to tower across central IL... but the storms were already firing across IA, where a tornado watch was already in place. But nothing coming into IL--yet. Would it? Well, the instability was really getting good--I was thinking about modifying the 12Z raob from DVN when SELS/SPC did it for me. LI's now -8 to -10 across northwest to central IL. Yikes!

I had other problems. I knew I wouldn't get paid until tomorrow, so that left a chase budget of $4 and change. Worse, my weather radio was starting to act up, and a backup one I gave to someone else to borrow for the day, thinking I wouldn't need it. Finally, it was finals week at NIU--no chasers available--and everyone else I knew had stuff they had to do. Murphy--I hate you!!!

However, all my other chase equipment and video camera were ready to go. Quick decisions had to be made. Based on what I saw above and at work, I decided to head for IA via route 88. But by the time I got off campus, hopped a shuttle to my car, and left about 3:30 PM, I was praying I wasn't too late!

At 4 PM I was near Dixon, when on WGN radio I heard... "The NWS has just issued a tornado warning for Scott County (near Quad Cities) IA, where a tornado is ON-THE-GROUND...

"D---!", I exclaimed, cursing myself for waiting so long, cursing my cold which was still nagging me a little. Well, now what. I was too late to see what would happen in the Quad Cities, or so I thought. I had one other option--at Sterling/Rock Falls, IL, U.S. route 30 branched west to Clinton, IA, while I-88 went WSW toward the Quad Cities. Praying I wouldn't hit traffic, I decided that was my best choice. I took the exit which bypassed the city, just past the Rock River.

Things were OK at first. About 5 miles further, I see a caravan of cars and a huge vehicle of some sort driving down the road ahead of the caravan, blocking traffic from going around it because it was such a wide vehicle. Oh noooooooooo...not a mobile home being moved!

At that point, I laughed. That's right, laughed! Because I took that as a great omen! A year earlier, the same thing happened at Northfield TX. Would this play out? Fortunately, this mobile home transport truck with it's delicate cargo was going 60 MPH (in a 55 zone). So I was still making great time, and wondering about the sanity of the driver since the road was not exactly smooth! All the while, the sky was getting more and more ominous, and more tornado warnings were flying for the Quad Cities. But then I noticed the winds were now from the EAST. They were backing even more than I had anticipated!

Shortly after 5 PM, I reached Morrison, IL, about 12 miles east of Clinton, IA. The DJ at the Quad cities station ("Mix 96", for those of you in the area), was professional, though you could tell that when all the off duty DJ's started calling him telling him each were seeing a tornado, he was wondering if he could be next! Now, where to go. Bingo! Tornado warning for Whiteside county, with a tornado warning extended for Scott County, IA! But as I sat in my car at 5:18 PM, 2 miles west of Morrison, a ridge to my south was blocking my southerly view. I could see it was dark off to my south...I can see clouds banding going into the storm...should I go up that ridge? Judging from the reports, I had time. I quickly found a road that headed south. I drove up the hill, with the sky becoming more and more ominous as I climbed. When I reached the crest, I slowed down and pulled off the road. Then I looked up and around.

I couldn't believe what I was seeing. A supercell heading for Lee county off to my southeast with a meso (Karl Schulze and Scott Olthoff from NIU were on that one, watching from the southeast, a much better view), the Scott county supercell to my west-southwest with meso obscured, and another to my south--with a cone-shaped tornado on the ground to my S-SW, about 10 miles away!!!

I had a perfect view, but I quickly looked away and around. A farm house with trees and power lines was just off to my left; I pulled over and made sure I wasn't the highest object around, close to (but not too close to) the trees and power lines. Most of the lightning was coming from the anvil, very strong positive bolts. I-88 was in the way and I had no way of going south. Besides, everything else out there was a valley with tons of trees, so why move? This was a fantastic overlook!

Then I took out my camcorder and began filming. The contrast was poor; it was quite hazy as dewpoints were now close to 65@, and I was a good 10 miles from the storm with rain partially obscuring it (but with a great view!). I watched the first tornado rope out after 3 minutes, lifting at 5:31 PM. The wall cloud was still low, however, and a minute later, another tornado came down, this one a narrow, cylinder-shaped vortex. It was hard to see. That one stayed down for another two minutes before it lifted. My first cyclical supercell--in Illinois!

Unfortunately, immediately after this second tornado, curtains of rain and hail wrapped around the entire base. A classic supercell evolved into an HP in a few minutes. Although I wasn't thrilled by that, to watch it happen was very interesting.

But I also knew something else. This storm was moving N-NE at 40 MPH, and it was approaching fast. So after looking at my road map, I got back on US 30 at 5:40 PM, headed east back into Morrison, then south on State road 78 back to I-88. At that point, the meso was off to my southwest. Turning west on a paved, but unknown road, I pulled off to the side and watched, along with a state trooper flying like a bat out of h--- going the other way, the mesocyclone pass to my west by about two miles, at 5:56 PM. It was really spinning, and heading straight for Morrison. But then the rain wrapped around from the south and southeast, blocking my view. I decided to head back toward Morrison, to see what would happen. The time was now 6:06 PM.

As I hit the town, the storm was still off to my southwest. I decided to get just west of town by a half mile. As I did, the wall cloud was now approaching me to my south-southwest. This was going to cross right over me! Too far west. I headed back east into Morrison, and said the heck with it, I'll watch it from the east side. But, that wall cloud was now obscured by a shelf cloud. Then a reporter from WSSQ-FM in Sterling, also chasing the storm, who I had passed going east a minute earlier, reported on the tornado I couldn't see, wipe out a building a half mile west of Morrison, blowing the roof and other debris across route 30. Gulp! Good call.

But now there was a problem. This thing was evolving into a squall line, and all I could see was shelf. More importantly, a new wall cloud had formed to my south-southwest, at 6:32 PM, by maybe about 5 miles. I was about 3 miles east of Morrison, and the sky looked an awful pea-soup green to my west and southwest, all the way south to the wall cloud. Further, my route to the east was being cut off by the Lee county supercell, moving north. I headed east anyway, hoping for some way out.

At 6:41 PM, I made the intersection of U.S. 30 and I-88 again. But, off to my southwest, was this monster rotating wall cloud, perhaps 3/4 of a mile wide (monster for IL, mind you). Off to my south, a wall cloud...is that a funnel??? To my south-southeast, that Lee county storm, moving in...

I headed east on I-88. The only thing I could do now was pray I could get inbetween the storms. But the moment I got on I-88 at 6:42PM, I was immediately greeted by 1/4 to half inch hail, and near-zero visibility crossing the Rock river. At 6:44 PM, I found an underpass, turned on the radio, and waited. A few minutes later, at 6:47 PM, the wind suddenly howled from the west, slapping my rear windshield with 1/4" hail. I turned around in time to see this rapidly rotating mesocyclone, obscured some by the rain and hail, pass behind me. Video was indeterminant whether or not the formations that are semi-visible were tornadoes or funnel clouds. It is a close call as to what it is, besides being a meso.

Well, a moment later, I saw pure white behind me, and then the rain and hail began to pick up, and I could see sheets of white feeding right into that meso, but wrapping toward me. So I got out of there FAST. I wanted no part of that!

Well, now the rain had let up, but then as I approached Rock Falls, it started getting heavy again. The radio announcer, trying to click off every tornado that was on the ground (or so reported to him)--suddenly got calls from his chasers and the public of a funnel south of I-88 approaching Rock Falls from the south. At that point, the rain let up, and...there was a spin in the clouds 2 miles to my south with a lowering! "The atmosphere has gone crazy!", I yelled into my camcorder, film rolling but used for audio only now. But I picked it up briefly and pointed it to my right towards the window for about 5 seconds. The view--albeit brief--is the circulation in the wall cloud. I headed for the Sterling underpass, since there were no ditches or substantial structures nearby. I wasn't alone; about 18 cars and trucks made it there.

Exasperated, wondering where the heck all this was coming from, and wondering what could happen next, I could hear the radio announcer describe the next events blow-by-blow just after 7 PM: "Big funnel, now it's lifting...it's gone". I caught the RFD with 1/4" hail and gusty winds...then it passed. I just sat there, watching pea to 1/4" hail in heavy rain for about 15 minutes. I had enough for one day.

As it turns out, that was the last funnel/tornado reported in northwest IL. I drove home and through the dying squall line, with heavy rain and occasional pea hail. All tornado warnings were expired or were cancelled. As radar showed, I was with several supercells that basically decided to merge over me near Sterling, with no way out. That was weird!

As I drove home, though, I was happy. I had heard no one was killed, and only one very minor injury. The spotters out there were great; I could have phoned in reports at several pay phones (was this a good chase?? PHONES nearby???), but spotters had things well in hand already, so I didn't add to the traffic, quite a bit of which was redundant. Local radio stations WZZT-FM, Morrison and WSSQ-FM/WSDC-AM, Sterling, simulcasted WSDC's great coverage.

But, I felt sorry for Paul Sirvatka and his crew of College of DuPage chasers, coming home from a relatively disappointing trip. I called my colleagues at the NIU weather office when I got back home and told them what happened. Then... "Hey Gilbert, did you hear what happened in Central Illinois and with Paul?? He was on a monster..."

I smiled. Illinois' chasers finally had their day, in their backyard. And I had my best chase ever, without having vacation time this chase season. "There is hope", I said as I hung up the phone...with my friends and colleagues now driving quickly to my apartment to see my video!