Why the forecast bust on Friday?

I was pretty hyped up about Friday, as was the CoD team and a lot of other chasers. The setup looked prime for quite a few tornadoes, and given the tornadoes the previous day, I was fully expecting a goodly amount.

So what happened?

In short, I don't know. Sorry, but meteorologists don't have all the answers.
Of course, what we tend to have is a lot of opinions on possibilities. :)

So what might have been wrong?

Moisture - the moisture was there at the surface, and according the the Topeka and Omaha 12Z soundings, it was pretty deep. By mid-afternoon the surface dews were in the low 60s. So I don't know that moisture was an issue.

Instability - by and large this looked okay. Omaha sent out a 20Z sounding.

There was a slight bit of capping at about 700 mb. The amount wasn't huge, and the cap (I don't know why people capitalize the word, Justin--it's a word, not an acronym :P) should have been able to be overcome. But I will discuss this a bit more in depth below.

Lift - there was tons of convergence along the occluded/warm front. It was actually one of the things I had feared the day before, that things would go too early because of all the surface convergence.

Shear - Plenty. But, you say, look at the 20Z Omaha sounding. Not plenty. 23 knots deep shear? True. At 20Z. But with the increasing wind fields, that increased to 46 knots by 00Z.

So that likely wasn't it.

I want to go back to the subtle capping we saw on the 20Z sounding. It wasn't a huge cap, an insurmountable cap, but perhaps a symptom of something that was insurmountable: subsidence.

Whenever you see an inversion with associated drying, it's usually due to subsidence--air sinking. The fact that there was what appeared to be a subsidence inversion at Omaha at 20Z may be enough, in fact, to have prevented convective development until later. Even weak, subtle subsidence can often be enough to prevent storms from going up. It can be annoying.

Later, at 00Z, we saw no evidence of this cap and lo and behold, storms fired around that time. So why didn't they go nuts at that point with tornadoes and big hail all over the place? Looking at the observations from Omaha, the temperature was 22°C at 23Z and 21°C at 00Z. A subtle cooling, but perhaps enough to make it so that the CAPE would decrease by a lot.

So in essence, there was some mid-level subsidence that prevented storms from going for a while--due likely to a short-wave ridge that was nigh on impossible to find on the water vapour imagery. By the time the ridge axis passed and the subsidence turned to subtle lift, peak heating had already passed and the storms that formed weren't able to take full advantage of the energy that had been present throughout the day.

I know there are a lot of disappointed people out there because of this bust, although they have a few things to do until the next chance for chaseable storms comes about, perhaps tomorrow (tornadoes not likely but maybe a picturesque supercell) and more likely Thursday and beyond.