The Northern Iowa Supercells and Tornadoes
of 11 June 2004

This storm was easy to forecast and easy to find, but there is always a problem; this time it was timing because the storm had a tornado on the ground by 1 PM in the afternoon. I figured it would be an early show, I intended to be on the storm by 2 PM, but not quite this early and it cost me the first and perhaps the best tornado of the day. Actually I did photograph this tornado from a distance, but I really was not at the party, yet. Fortunately a good choice of Iowa back roads (love that road grid up there) got me right on target as I approached the cell from the south. I had driven from York, Nebraska where I stayed the night and made the morning forecast. So, it was not a trivial distance that needed to be covered, still, by the end the day I had photography of seven tornadoes, five of which I did a good job covering. I'm still breaking in a new digital camera and I'm not quite up to speed on it yet. I still have problems with low light focus, but I do love the high shutter speeds I get in good lighting; one tornado I shot at 1/2500 of a second, amazing.

As the first supercell approached the Minnesota border it was looking tired and spewing out volumes of cold air. The tornado warnings were still flying as I pealed off to the south. My hope was the warnings would hold some of the non-hard core chasers north, thus thinning the crowd. This season I've seen more "locals" out in their cars staring at every turbulent cloud whirl. In Iowa they are especially bad about parking and standing in the middle of the road, which can make for an abrupt surprise when topping a hill, fortunately I didn't collect any of them in the grille. The chase went pretty smooth other than one aborted turn on to a dirt road, which upon first galnce was a mud-bog, so I decided not to take it at the last second. Unfortunately, there was another chaser on my bumper that had to lock up the brakes, but we didn't exchange paint, so hopefully he'll get over it. As for the police, they were out in big numbers watching the storm, driving faster than the chasers (as usual), and being quite friendly I might add.

All images and text © copyright Gene Moore

 


When I first caught sight of this bomb I knew I was in trouble, fortunately it was cyclic (individual exploding towers - not steady state) at first and that bought me some time, but not much. Enduring a storm sending up giant towers when I'm miles away is difficult......some wait for me, some don't.


    


Finally the big blowup came and the anvil spread out across the windshield, I knew I was late and tornadoes we're probably on the ground. As it turned out I was correct, it was 2 P.M. and the party had started without me. Right after I snapped this shot the tone alarm went off on the NOAA Weather Radio for the first tornado warning. Unfortunately the secondary road speed limits are much lower in Iowa and it was difficult to make good time.


  
 


I photographed one tornado in the distance and then quickly got into position for the next one. This tornado may have been in progress as I drove up, but it still put on quite a show.


    


As dry air wrapped around the tall funnel it extended deep into the storm. The debris cloud was over the hill and out of sight at this moment, but would appear very soon. I remained on gravel roads that were getting rather muddy but still easy to navigate.


  
 


The debris cloud shrouded in a white froth of spinning water (left in the fields from the rain) was visible to my west.

 


The debris cloud move close to structures during this time but I saw not buildings get hit. The very tall funnel snaked around for quite a while sending thin white streamers to the ground.
 


This turned out to be the best show of the day so I took many shots. Meanwhile a news helicopter hovered overhead also capturing the spectacular funnel hanging out in the sunlight.

  


Briefly the funnel strengthens and sends another strong vortex to ground before weakening again. The curves in the side of the funnel wall generally signal the beginning of the final rope out stage leading to dissipation.
 


The tornado lifts off the ground and begins to dissipate at this time. It slowly narrowed into a thin rope before dying out.

  


A new tornado rapidly forms to the northwest near the town of Emmetsburg Iowa. This is a wide angle shot of the storm at the time.
 

The tornado passes west of town; I'm sure giving residents a fright.

 


The tornado begins to dissipate as the storm appears to run off and leave the debris cloud behind. This causes the funnel to become stretched out.
 


The funnel narrows dramatically and breaks into spinning sections dragging the debris cloud behind.

  


Finally in a dramatic end the tornado leaves only a filament of the rope in place still churning up the dirt in a nearby field.


Another tornado develops from the now fractured wall cloud. Although it remains strong and low to the ground the wall cloud appears to be getting weaker as the storm moves north into cooler air. This image was shot from the road on the west side of Five Island Lake.

  


A wide and briefly violent tornado forms to the west, but to my surprise only lasts about a minute. This certainly signals the storm is getting weaker and lost the ability to plant a large tornado on the ground .

After this tornado a series of numerous cone funnels formed and dissipated, some perhaps briefly reaching the ground, but none equalling the previous performance put on by the supercell.
 


After the first supercell neared the Minnesota border and weakened I quickly drove back to the south. A strong and cold gust front trailed behind the supercell for about 50 miles killing the tornado potential of the trailing storms. That didn't stop the warnings from being issued on the "undercut" storms though. This gave me time to reposition near Ft. Dodge and watch explosive development to the west of town. Finally this small tornado was responsible for the sirens sounding in town but it stayed in open country.

  


A flat swirl develops in the base of a line segment south of Ft. Dodge. This is accompanied by an RFD (rear flank downdraft) cut into the storm, seen on the left edge of the image. By this time the cold surge from the north had lost some of its punch, but had not totally dissipated.
 


A dramatic debris cloud forms under the bulbous lowering . This circulation did damage to a farm and outbuildings and was filled with suction spots.


  


Another shot of the debris cloud and the lowering that was spinning overhead. This scene persisted for a couple of minutes before a classic funnel formed.

As rain wraps around the circulation a funnel begins to descend. The wind and rain made photography a nightmare but I stood my ground while everyone else left the highway and farm road intersection. I had an old beat up umbrella that came in handy. I'll be adding some much better shots of this tornado in the future that I took with my old slide camera.

After this tornado dissipated another stunning red funnel formed in the setting sun at sunset. I photographed that tornado through a curtain of rain that reduced the contrast, but I'll try to get some shots on-line if I can bring out the funnel with Photoshop.

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