Tornado south of Ogallah, Kansas about 2205 UTC, April 10, 2005

Eric Nguyen, Scott Currens, and I observed five tornadoes this afternoon and early evening on several supercells of different types, from an early cold-core, low-topped cell to more classic supercells firing along the dryline bulge.

Our first tornado of the day was very small on a cell in extreme northwest Scott County around 1:30 or 2:00 PM. These storms fired as instability wrapped around the surface low and the dryline bulge began to impinge on the marginally unstable air. Easterly surface flow most likely contributed to steep low level shear as our Wx-Worx did not indicate any shear at the time of the first tornado. We observed a very small, but identifiable supercell on regular reflectivity (via GRLevel 3) about twenty minutes prior to that initial tornado. Lapse rates were quite steep and cold midlevel air combined for an early cold-core tornado in a long event.

We hurried east as storms fired along the dryline sloping back to the southeast and south, continuing to pursue cells in Lane and Ness counties. Our next tornado was remarkable in that the circulation first became evident over water. We were crossing the dam on the eastern edge of the Cedar Bluff Reservoir in southeast Trego County when a low-hanging wall cloud produced a visible and violent rotation on the surface of the small lake. This was amazing as we had just joked about how the turnoff from the dam would be a perfect location for our storm to produce a picturesque tornado. Unfortunately, the entire funnel did not fill in, but the storm was only getting started.

We observed another tornado shortly thereafter, a tall white cone that swirled tumbleweeds on ground and kicked up black dirt. This was south of Ogallah, Kansas by about six miles.

At this point we realized that many of these storms were advancing north and interacting with some boundary draped west to east---perhaps an outflow boundary from earlier convection*, and dropping tornadoes while simultaneously slowing down. Surface winds along this feature were due east into the storms. Even storms which ingested inflow coming through the downstream precipitation of the storms to the south or southeast seemed to strengthen and rotate much more violently when interacting with this boundary. Once they moved north and into the cooler air, they weakened.

Our fourth tornado was a dark, tall stovepipe, the best-looking and longest-lived tornado of the day, which stayed on the ground for probably five to seven minutes and went through several graceful mutations, with a sleek funnel to the ground and a roiling debris curtain at the base. This was about three miles south of Ogallah on State Road 147.

By now we understood the magic of the boundary and hurried to get south for the supercell then entering Hays, Kansas. There was another storm to the southeast of that, and a third even, which we called the “Great Bend” storm. Eventually, the second storm in this train would produce another tornado, which we did not see, near Interstate 70 about one mile west of Russell. At last we reached Russell and raced north on 281 in time to see our final tornado, another tall stovepipe, about six miles north of Russell. That would be the last productive storm of the day for us, and we retired to Salina and dinner at Spangler’s along I-135.

I want to thank Eric Nguyen and Scott Currens for a remarkable forecast that included playing extremely close to the low early in the setup and assuming there would be enough time to move out ahead of the dryline for the more conventional, classic supercells. There was, and both areas produced for us. I want to thank the outflow boundary without which I don’t know that anything but that first low-topped storm would have produced. As well, there is no question that chasing a day like this without some form of uninterrupted data would be very difficult or impossible. Many things came together perfectly for the best April chase of my life. It was fun as hell.

Click the image and look for the circulation in the center of the image toward the back (digital still)

Cropped segment showing tornado over Cedar Bluff Reservoir

Tornado # 2 (digital still)

Tornado #3 (video grab)

(video grab)

This image and above are digital stills

This image and below are video grabs

Tornado number #5 north of Russell, Kansas ~2350z

Cold core chasing is cold!

Tony Laubach's video ran on Denver television, including this shot of my truck. 

* see Jon Davies' excellent case study for analysis of the complicated and fascinating surface features of this event

Cyclone Road