June 24, 2013
Statistics
2 miles E of Sterling, CO 9:19 AM 6/24/2013
North Sioux City, SD 7:52 PM 6/24/2013
Summary
Weakly sheared, moderate instability warm front chase on the NE, SD, IA corner. Cap failed to break and blue sky busted spending the night in the Sioux City area.
Crew and Equipment
Chase partners: Jennifer Brindley Ubl, Sean Casey, Jonathan Williamson, Nick Nolte. Equipment: Canon 60D, Canon t2i, Canon EFS 10-22, Canon EF 50mm, Sony HDR-xr500v..
Video
Map
Details
Our fourth day out on the plains caravannign with the TIV. Southwest flow persisted including a moderately unstable airmass so we decided to keep chasing. There was some uncertainty during the morning in Sterling, CO as to where we were going to target. Storms looked more like in southwest KS where the lift and instability were greater. Meager low level instability, lack of directional shear, and dewpoint spreads looked to preclude any chance of a tornado at this target, however. In northeast NE, however, there was ample low level instability and a weak boundary to play with providing directional shear. There was less left, however, and we'd risk a cap bust up there. We decided to go for the tornado show even if it meant a lower chance at storms.
Heading toward Valentine, the tornado probabilities dropped and a cap bust seemed imininent. We stopped to consider our options before continuing on toward Sioux City to make the best of our day, get a decent dinner and a room, and hopefully be in position for the next day. We spent the last half of the afternoon waiting in a park outside Sioux City for storm initiation which never happened. We met one local curious to see the TIV, who had video on his phone of a tornado that occurred in Dexter, MI last year that Nolte had also witnessed. It was quite the coincidence.
Cap bust boredom leads to stick fights
The Famous Daves in Sioux City, IA is the one good smell in that town.
Conclusion
An epic cap bust. I thought our best shot at a tornado would be northeast NE given the low level instability and capping. Storms were much more likely in Kansas, but the parameters precluded tornadoes. Indeed an elevated, and linear line of storms went up in KS, but the cap also won at our target and we cap busted not seeing any storms at all. We were in it for the tornadoes on this one though.
Lessons Learned
- Picking the tornado target instead of the storm target is sometimes a double down bet that is more likely to cap bust.