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  • Andrew Pritchard

July 16th 2015 | Monmouth/Cameron IL Tornadoes

Good news - you never have to hear me talk about a tornado drought again. At least, not for another 3 years or so. The drought finally ended yesterday at 3 years, 3 months, 2 days.

This one almost snuck up on me. Almost. I noticed the extremely favorable wind field the day before, but there was minimal instability showing up and none of the convection allowing models suggested a single storm would go up and tap into the abundant wind shear. I made plans to take a half day earlier in the week on Thursday the 16th to do some things around the house, and figured I'd just stick to that plan.

Fast forward to the morning of the 16th, and low and behold, there is some suggestion that storms would actually erupt in western Illinois - in an environment extremely favorable for supercells and tornadoes. Given the uncertainty however, most forecasts were still quite conservative.

Storm Prediction Center Day 1 Outlook shows a 'Slight Risk' across western/central Illinois:

Tornado probabilities only at 2% in the target area:

Around 10 AM I shot my dad a text and let him know that things might actually be looking worthwhile during the afternoon if he wanted to give it another shot. I finished up the morning at the office, and we hit the road around 2:30 targeting the highway 136 corridor in western Illinois.

The environment was absolutely primed as we commenced west down 136. Instability was strong, with surface based cape values of around 4500 j/kg, with strong southeast winds along the warm front leading to storm relative helicity values of 300 m2/s2 or so. We just needed a storm.

We stopped for gas and a coke in Havana and met up with Colin Davis, as a storm erupted over Fort Madison, Iowa and began crossing the river into western Illinois. This was our storm. Radar image at 6 PM shows our supercell as we approach from the southwest:

It was quickly Tornado Warned as we navigated around Macomb, ultimately picking up the storm near Rose Hill. Unreal supercell structure appeared overhead with a spiraling updraft visible above the tall summer corn. We struggled to find a decent view as we navigated rolling hills and the mature corn - which really can't be understated as to how difficult it makes seeing any lower level features on a nearby storm. It's just as bad as being in a forest, at times.

Cell phone picture of the storm updraft with mid-level inflow bands feeding into it:

The Monmouth/Cameron beast as we approached it from the south:

Cell phone picture, corn corn corn corn:

Our first view of a tornado came west of Monmouth by about 5 miles as a slender cone became visible between rows of corn and through the rain. It wasn't easy, and it wasn't pretty, but the tornado drought was over at that moment.

Grainy video capture of the first tornado southwest of Monmouth:

I wanted more though, and the radar representation suggested we would be getting more. As the storm approached Monmouth it was very obvious that a large tornado was underway. We got several glimpses of the very dark storm base while a broad tornadic circulation spun away doing damage south of Monmouth.

Large tornadic circulation very near Monmouth, IL:

At this point we were having all kinds of issues as the storm became HP and was being caught by a line of storms coming up behind it. A menacing couplet continued just to our north, and we got one brief glimpse of very strong rising motion as a tornado developed just a 1/2 mile to a mile to our north.

We had been paralleling the storm along 160th Street, which was iffy at best, and I wanted to find us a better east option to get out of the rain quicker. This was where things got hairy and I began to lose my situational awareness. Even though we had just seen a tornado developing not more than a mile to our north - and an easterly storm component that meant that the tornado would not likely be getting any more than a mile further north of us - I took the next North-South option and decided to head north in hopes of reaching Highway 5 into Cameron, knowing it would be paved and would get us out of the storm.

As we turned north and crept up 100th Street about 2 miles west of Cameron the tornado came into view for about 30 seconds. It was large, with a classic liberty bell updraft/rfd clear slot. Rain quickly overtook us and the tornado was gone.

Large tornado two miles west of Cameron, IL crossing 100th Street:

This was where I *really* drop the ball in a way that I just don't understand. The large tornado crosses the road in front of us about 1/2 mile to the north - we flip around and head south back to 160th Street and parallel the tornado again for 2 miles until we hit Hwy 15 which goes straight north into Cameron. Even though we had *just* seen the tornado again for the second time knowing it is just a mile or less up the road - I have us plow north up the road hoping to again hit Hwy 5 in the town of Cameron. Why I think an east option in a town that is about to get hit by a significant tornado wrapped in rain is a viable escape option, I just don't know. It's just walking up to the front door of a house and seeing it on fire - and then walking around to the back door and walking in. Perhaps after a 3 year drought I forgot how tornadoes work, I just don't know.

Crude map showing our navigational route that led us into the Cameron tornado. Seems so stupidly obvious when you aren't in suffocating rain:

As we crept up 140th Street just 1/4 mile south of the town of Cameron, the tornado clipped us as it passed through Cameron. Incredible winds began rocking the vehicle with small debris airborne - in the video below you can hear my dad mention the debris as I recommend we stop to ride out what I again assume is just RFD winds - even thought I had *just* seen the tornado in this area. Moments before this, Colin had texted me, recommending we stop in what is now somewhat of an erie text sequence. 'Tops' was a typo, and should have been 'Stop':

Radar screen shot showing my location in the very strong velocity couplet as the tornado hits Cameron. Again, I don't know how you miss something like this:

As we sat alongside a farm house, an entire shed flew across the road and into the corn field next to us. That sound will be stuck with me forever. The crash sounded like lightning hitting beside the vehicle, until I saw the wad of sheet metal and wood fly into the corn field. I had us pull forward past the farm house so that if the entire farmhouse decided to go we wouldn't be in the immediate path. Luckily we only received a glancing blow as the core of the tornado passed through Cameron about 1,000 feet up the road.

Near zero visibility as the tornado moves through:

I was still fairly unable to process what had happened until we rolled forward and saw power poles snapped at the base laying across the road, and then the eventual damage inside the town of Cameron. This was actually the first time that I had rolled into a town just minutes after a tornado gone through. The smell of natural gas from numerous leaks across town filled the air, with what looked mostly like roof/minor structural damage in the town. It appears that damage got worse as you headed deeper into town, but all north options were cut off and blocked by debris.

Tree damage at the farmhouse where we pulled over:

Roof damage to the farmhouse:

Damage visible with roads blocked off as we head north into Cameron:

Powerpole snapped off entering Cameron:

Brake lights again entering Cameron on the south side. Natural gas leaks could be smelled in the air at this point:

At this point my phone began blowing up, and I realized just how thoughtless what I had done really was. I just don't know how you forget that you'd just seen a significant tornado cross one north option - go east a mile - and then try the next north option with zero visibility. It is what it is though at this point - and the tornado drought is over. My thoughts go out to those in Cameron.

Video from the chase, including the Cameron tornado:

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SKYDRAMA | Meteorologist & Atmospheric Photographer Andrew Pritchard

I'm a meteorologist born and raised in the American Midwest passionate about forecasting and observing severe storms.

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