Clinton Iowa Tornado April 9 2015

Apr 12, 2015


Chased HP supercell from southern Iowa to Illinois border, finally catching developing tornado at very close range near Clinton. Celebrations were short lived as historic event then unfolds back in Illinois.





Tornadoes: 1
Hail: 1.25″ (Half dollar)
Wind: est 70mph RFD
Milestone: First multi state tornado. (IA-IL)

The Forecast:

Slow moving, deepening low pressure system forecast to track across Iowa into Wisconsin. Ahead of it, deep moisture and strong instability for April would be present. Warm front draping from surface low across northern Illinois appeared ripe for supercell development. Capping was forecast to be non existent and numerous storms were expected. Shear was somewhat veered in the presence of negatively tilted trough, but quick backing near surface low and warm front would enhance tornado potential. Chose to target just east of the surface low/triple point for maximum chance at a storm/tornado. SPC began the day with 5% tornado probabilities but quickly upgraded to 10-hatched once it was clear area would destabilize as forecast.

Detailed Account:

This was one of those classic midwest conditional days. Forecast models showed favorable shear and instability profiles for big supercells and tornadoes. As always there were concerns overnight convection could ruin the days setup. Being early in the year, and after yesterday’s failure I told myself I wouldn’t let myself fail today. After an all night drive from Western Oklahoma, Alec and I found a motel in Newton, IA around 3am to crash at. I talked to the manager and told him we just needed  a place to crash for 5 hours and would be on the road right away, he gave us a discounted rate and we got a room for only 55 bucks. the 5 hours of sleep felt great and we were recharged.

We agreed to target the surface low, but were leery of the Illinois warm front target further east. I have been burned on these types of setups before, opting for the “more obvious” target. Everything we saw on the models indicated storms would first get going east of the surface low. This made sense as you often get an arcing line of storms early in the day near the surface low in these types of setups. The NW storm always seems to produce a tornado and that is the storm we wanted to be on. We jogged east and played our waiting game in Iowa City. To our surprise, initiation occurred along the cold front, near the IA/MO border. Son of a…it was time to backtrack to get on the storms as soon as possible.

We caught up with the storm near Bridgeport, IA…which is a very smelly town. I am not kidding either, there is a large compost plant or something and the area stunk. It was quite an analogy for how I feel about chasing in Iowa. Our first look at the storm revealed hazy HP structure, but there was a wall cloud with some weak rotation. It was trying to get organized.

This part of Iowa isn’t as chaser friendly as the rest of the state since the Des Moines river carves its way through the terrain. Many roads were not straight, and most dead ended. Additionally, the area is populated enough that there are slow moving locals everywhere. Trying to reposition the storm’s rear flank gust front overtook us with blinding rains and 60mph straight line winds. We cat-n-moused it as best we could, occasionally escaping the core to get a 2-3 minute view from inside the cage. The storm appeared very disorganized. Then something interesting happened I wish I had captured on film.

A black mass came crashing down ahead of us, it hit the ground and rapidly spread northward and overtook us. It looked as if someone dumped black paint out of the storm, thats how dark it was. I have never seen anything like it. As it engulfed us we were slammed with even stronger winds probably in the 70mph range along with hail up to half dollar size. I suspect the storm dumped its core as it began a new cycle. Ive heard of this process before, but to witness it first hand was pretty neat. Sure enough, the storm tightened up its rotation and the first tornado warning was issued. We managed to escape the core again and emerged just outside the cage to see a better organized and rotating wall cloud.
Iowa Wall Cloud

Again though, unfavorable roads, towns and slow moving locals hindered our forward progress. We were nearing I-80 at this point, but of course the on ramp we needed was closed so we needed to detour which cost us more critical time. We had been chasing for over 3 hours now and gas tank was nearing the 1/4 mark. We finally got on I-80 just west of the Quad Cities, the storm was pulling away to our northeast, the couplet had now really tightened up and showed a classic signature indicating a strong tornado. Our only option was 61 north and I floored it to gain some ground. We started to encounter overturned semis as the likely tornado had crossed the highway minutes before our arrival. Turning east on 30 we came in behind the occlusion of the tornado. We had just missed it.

However, our storm was cyclic and a new circulation was getting organized to our southeast. I hook sliced between the two circulations to get ahead of the new one. A very large, low hanging wall cloud soon came into view, the left edge quickly whipped around back to the right and I new tornadogenesis was imminent. I slowed to a crawl as we would be unable to get ahead of the developing tornado before it crossed the road. Only a moment later the first vorticy spun up from the ground. Our first tornado of 2015 was now underway, and we were 100 yards or less from it. The tornado crossed the road in a multi vortex state, black condensation whirls confirmed its presence to us.


The vehicle ahead of me is Aaron Rigsby, who we randomly bumped into along the way. We were the only 3 chasers on this storm at this point, as many others either gave up or fell behind due to the difficult nature of keeping pursuit. We felt quite accomplished at this point. The tornado quickly became obscured in rain, but gave us a faint, fully condensed view before disappearing entirely.


The tornado was moving towards Clinton, IA where it would go on to do EF-1 damage by destroying some barns and other outbuildings. By now my gas needle was hovering just above E. It was time to fill up. We wiggled through town and found a gas station as the storm quickly pulled off to the east. This is where the day rapidly went downhill. While filling we up began celebrating our catch, being as difficult and hard earned as it was we were quite elated. We sat there chatting, looking at our video, filling up, buying snacks. We figured the day was done…and were ignoring the radar. 15 minutes had gone by when Alec decided to take a peak at the radar and we noticed a nice cycle shaped storm 65 miles to our east in Illinois. “oh F–” I exclaimed…”that is going to produce a beautiful tornado.”

Years of chasing has taught me that certain radar signatures are indicative of beautiful tornadoes, and there it was. We began to desperately dash east. I opened facebook as my heart sank into my stomach, just waiting for the inevitable pictures to show up. And they did. The storm went on to produce an incredibly photogenic, long lived, violent EF-4 wedge tornado near Rochelle, IL. I watched in horror as imaged of a white wedge starting flooding social media. Many of the the chasers present were simply just driving home and the storm blew up ahead of them, or they were fellow IL chasers who stayed home because they thought the days potential wasn’t there. They simply left their front doors after the storm went up. What a slap in the face and slug to the gut, after all the blood sweat and tears we poured into our hazy HP intercept. The rug quickly got yanked out from under me. This tornado has gone on to be strongest tornado in Dekalb and Ogle counties since records began and was the first violent class tornado in the NWS Chicago warning area since the Plainfield F5 back in 1990. Owch.

Our moods were ruined, we had a depressing dinner at Perkins in Rockford, and then went back to Alec’s to drown our sorrows.


Missing the historic event so close to home stung, a lot. This is going to be a date referenced for a long time, and one I will loathe until redemption is had. Still, our skillful close range intercept is nothing to scoff at and is an accomplishment in itself. This is a new approach I have been working on since 2013, and I am confident I will be able to use it to do amazing things in the future. providing the opportunity. Also, the survey revealed the tornado had a path length of 13 miles and did not end until it was in Illinois, so this is my first multi-state tornado. Any chase I can claim a new milestone is a good one. I am happy for my friends who caught the tornado, but sad I couldn’t be there to share the experience. I also find myself getting through the grieving process quicker. Perhaps as I move deeper into my chasing career I have come to accept the fact things like this happen, its just part of chasing. Bring on the next one!


Radar Grab:
April 9th 2015 2

Chase Map:

Detailed Map With Tornado Track:

Tornado Info:

RATING:                 EF-1
FATALITIES:             0
INJURIES:               0

START DATE:             04/09/2015 
START TIME:             5:40 PM CDT
START LAT/LON:          41.8152/-90.0644

END DATE:               04/09/2015
END TIME:               6:00 PM CDT
END LAT/LON:            41.9154/-90.0644

SPC Storm Reports:

<—-Previous Chase                                                                                 Next Chase—->

Leave a Comment: