Here is the 18z ob sounding from
TOP (click) and it shows the quite small/straight hodograph (and small 0-1km SRH) and also exhibits the very shallow boundary layer moisture present. The strong insolation through the afternoon helped to support the strong instability (e.g. 1500-2000j/kg MLCAPE across the open warm sector) but also helped to mix out much of the already shallow moist layer. In fact, compare the
12z and
18z ob soundings from TOP, which pretty much shows the moist layer mixing out even further (from the strong convective mixing) -- with the 18z TOP showing a hydrolapse right above the surface! I'm not totally saying the shallow moisture was the problem... But the small 0-1km SRH (e.g. 50-100m2/s2) definitely didn't help any potential significant tornadic activity.
The shallow boundary layer moisture also helped contribute to high LCLs over a lot of the warm sector (per SPC mesoanalysis, around 1400-1600m~ AGL invof most of the KS activity) which also didn't help tornado potential. Take the one supercell near Junction City, KS yesterday afternoon, which showed quite a bit of promise (per ICT and TOP radars) with strong rotational velocity in the lowest SRV tilts for at least a half hour (which prompted the TOR issued by TOP) but the rotation quickly was lost as it moved north-northeast (at a decent clip of about 55-65mph). In addition, thermodynamically speaking, yesterday reminded me of last Saturday in the eastern TX panhandle/western OK (with our supercell near Sayer/Elk City looking awesome with a striated appearance and rotating wall cloud with strong inflow) with our storm quickly losing low-level rotation and turning to outflow dominant crap, owed to
1. Weak low-level shear (e.g. 50-100m2/s2 0-1km SRH)
2. High LCLs owed to a dry boundary layer (very low boundary layer RH / large Td depressions) in turn allowing for stronger evaporational cooling within the supercell's downdraft, which will tend to lead to greater outflow dominance (and destroying the potential for low-level mesocyclones/tornado development) within storms
The storm of the day appears to have been well documented by numerous chasers (e.g. Darin, Dick, Mike H, JB Dixon and at least a handful of others) and this storm was the closest to the surface low than any others (and perhaps ingested roughly ~100m2/s2 0-1km SRH and ~1500j/kg MLCAPE -- perhaps less once the storm approached Hanover and produced those tornadoes) but quickly weakened as it moved into cooler and drier air in southeast NE (with even higher LCLs) and quickly destroyed itself as it moved through Beatrice (and likely began to feed off inflow parcels above the surface layer). Most of yesterday's 19 tornado reports were from that supercell (about a dozen of them)! At any rate, if we would have gotten stronger low-level shear (and lower LCLs) during peak heating then we would have probably seen more tornadoes across KS (and into NE) as the surface pressure falls led to an isallobaric response in low-level wind fields -- by backing them within a matter of a couple hours during the mid-afternoon as the sfc low shifted northeast -- and increased the low-level shear quite a bit (0-1km SRH increased from 50-100m2/s2 to 250-300m2/s2 in portions of eastern KS between 20z and 23z) but MLCAPE had already decreased by the evening and the high LCLs certainly didn't help tornado potential.
