Though this day turned out to be a bust, I'm throwing this page together since there was a very good potential for supercells. The morning maps depicted a setup more typical of springtime than late August: a nice surface warm front was oriented east-west from Nebraska to western Illinois with widespread southeasterly winds and Tds ranging from the upper 50s in northern Iowa to the lower 70s in southern Iowa, a surface low in central Nebraska, 50 knot speed shear with >90 degrees directional shear (helicities approaching 400 and EHIs of 8!), forecasted LIs of -10 would yield CAPES near 4500, and a modest vorticity maximum forecast to overlay the previous features by late afternoon and evening would help with ascent. The low-level jet was nearing 30 knots and the nose was directed towards northern/northeastern Iowa. CINH was not a major factor, so I chose northern IA as a broad target to chase.
  After making a couple data stops at libraries along the way, things were still looking good. When I had arrived at HWY 9 and I35 in northern Iowa the situation hadn't improved and sunset was an hour away. The deep convection ensued at 9:30pm forty miles to my north near Alber Lea, MN. I'll chalk it up as the nocturnal enhancement of the low-level jet near sunset that initiated the convection. Though the vort max was in place aloft, it's also possible that its effects weren't felt below 500mb until late evening. Either way, no convection became surface-based south of Albert Lea, so the tornado potential was wasted.  At the very least, I forecasted my target fairly accurately and got to throw over 700 miles on my 127K mileage car!  I did see some high-based storms on the way home Wednesday morning and afternoon in Iowa, however it was nothing interesting to look at.