May 1, 2012


Initial Target: Sioux Falls, SD
Departure: Westchester, IL 8:00 pm April 30
Arrival: Worthington, MN 9:30 pm
Intercepts: Tracy, MN
Tornadoes: 0
Hail: Non-Severe (not measured)
Wind: Non-Severe (not measured)
Features: Updraft Base, Non Rotating Wall Cloud, HP RFD Core
Miles: 776


Day before the day setup in southwest MN. Targeted dryline play near Sioux Falls, SD for discrete afternoon storms. Intercepted high based cell near Tracy, MN with high contrast updraft base before cell disorganized. Dropped to second storm in line noting dramatically contrasted and colored non-rotating wall cloud and followed until line gusted out. Dropped south into northwest Iowa at dusk to intercept tornado warned HP supercell, noting RFD core obscuring updraft features and big inflow band. Abandoned storm at dark due to visibility issues, and core punched line north of the cell noting winds approaching severe levels. Stopped in Worthington for dinner and room.

Crew and Equipment:

Chase partners: Jennifer Brindley.  Equipment:  Kenwood TH-F6A Tribander, Dell Inspiron Laptop.  Millenicom 760 USB datacard and cradlepoint router, Holux 236 GPS, Canon 60D and EF-S 10-22mm

Photography courtesy: Jennifer Brindley




Tuesday, May 1, was kind of a day before the main day type setup in in Minnesota. Conditions looked decent for a two day run, so Jennifer and I decided to give it a shot and see what we could get. We met up in Madison on Monday night, stopped for the night in the Dells and then were rolling toward our target early Tuesday morning. The best shot at tornadoes looked like it would be along the warm front in central and eastern MN. I didn't like the terrain up there due to all the trees and lakes, so I decided we'd give it a shot playing the trailing dryline in southwest MN, picking up Tail-End-Charlie near Sioux Falls. Surface winds would be more veered down there, but I figured we'd have a more relaxed or even more photogenic chase, despite lower tornado odds.

We took 90 west across southern MN and stopped a few miles shy of SD to let the storms initiate. We waited a few hours, shooting scenery, and trying to make cloud time lapses before cells finally blew up. We caught this cell near Slayton, MN and waited for it to get its act together. You can see a rain shaft on the right which would be the forward flank of the storm, and the updraft base in the center of the image that would hopefully mature into a supercell.
Wide angle, portrait shot looking up at the mammatus and anvil stretching overhead:
Some farmers stopped by to say hi and see what was up. We told them about the storm we were watching and one of the guys was very impressed, an avid fan of Discovery's Storm Chasers.
Our storm was looking more photogenic as it approached, but we explained to the farmers that it would need a bit of time yet before it posed any real severe or tornado threat.
Jenn shoots the high contrast updraft base:
For what was little more than a garden variety storm, this storm sure was photogenic and high contrast, with a textured albeit high updraft base, and streaky backlit rain curtains:
My shot of the same structure a minute or two later as the storm starts to pass to our north. The rain was coming down in neat looking cascades, and there appeared to be a bit of a notch in the back of the updraft base. I was hoping we were finally getting some supercellular characteristics with a rear flanking downdraft clear slot, but it might have just been wishful thinking.
Smartphones are the farmer's tool of choice today
Huge farm machinery in front of the storm:
Jenn's black and white version makes the storm a bit more ominous looking:
We followed the storm up past Tracy, but rain started to fall through the updraft base and it looked like the storm was falling apart before it had even really gotten its act together. Stopping east of the storm and looking west there was a bit of a high based shelf in front of the precipitation core forming.
The northern edge of it started to pull in some scud from the rain cooled air. It looked neat, but was rather junky structure wise.
We moved north to keep up with the storm hoping it was attempting to develop a wall cloud. We wound up on a gravel road that widened out into just a huge square lot of gravel. We didn't know where the road went after that and some people standing about in the lot looked at us strangely as we must have wandered onto their property. They were friendly enough and directed us back onto the through road. Our storm had completely crapped out by then though so we dropped down the line to the next cell.
A beautiful sight came into view as we approached the storm. A white and purple lowering, clouds swirling above it, with a green core behind it.
The contrast and colors on the storm were very dramatic, but there was no rotation evident.
A pano of the whole storm:
The storm was moving a good clip faster than last one, so we had to race down the road to stay ahead of it. The interesting lowering passes to our north:
Another shot of what looked like a supercell's bowl shaped wall cloud, but again there was no rotation evident.
The storm's gust front bowing outward and racing eastward:
We tried to keep up with the storm a but it was obvious it was gusting out into an outflow dominant mess. A turbulent wake known as the Whale's Mouth extended south of the storm. We stopped for a couple minutes to shoot the turmoil stretching overhead:
More storms fired further to the south, one a nice looking supercell with a hook echo that picked up a tornado warning. We got this last shot of our outflow dominate storm and then raced southwest past Worthington into Iowa to intercept the new storm.
It was just about dusk by the time we got down there, so we were pushing the low light performance on our cameras. We had to detour off of highway 60 due to construction for a few miles but were able to get back on further south and still ahead of the storm's core. We turned west south of Sibley, IA and headed right for the storms inflow notch. The storm had just lost its tornado warning, but it still looked extremely ominous and threatening compared to our earlier intercepts. A mean looking rear flanking downdraft on the left, and an inflow band feeding into on the right.

With the light fading fast and the precipitation obscuring the updraft base on the storm, our visibility was just not there. The storm was on the verge of gobbling us up and we didn't want to get caught in an HP at night so we turned around and raced east back toward 60 to heard north.

Looking up at the inflow band as it moves overhead:

The forward flank of the storm clipped us before we made it 60 and we got hit with some pretty gusty outflow blowing hard south across the road. We made it out ahead of the storm though. We booked a room in Worthington for the night but a squall line had gone up north of the storm and we'd have to punch through it to get to town. The line was not warned, so I figured we'd be alright. I turned us west on the MN/IA border to take our 60 detour and we hit the line. The radar updated and there was an embedded supercell with the hook moving right over us.

We were hit by winds that had to be approaching severe limits and I was spooked there be might be a tornado lurking in there as well. I kept the van on the road though and we made it out in the clear air on the west side of the storm without incident. Not wanting to alarm Jenn, I didn't tell her about the hook we drove through until afterwards. We grabbed dinner and a room in Worthington, looking forward to the next day's chase.


No tornadoes on this chase, but several photogenic storms and a beefy supercell at the end. I'd call the chase a success because of it's photographic qualities and supercell structure we did manage to squeak out of it. There was a bit more tornado activity on the warm front, but nothing that made us too jealous. Storm chasers got some funnels and a bit more rotation, but trees and lakes did hinder some chasing of the chasing up there.


Lessons Learned: 

  • Don't underestimate an unwarned line of cells, especially at night.

  • Look carefully for embedded supercells before punching through a line of storms.