bdgwx

I was getting ready to mention that as well. A vigorous trough with lots of kinetic energy at all levels colocated with adequate instability could mean trouble if many of the pieces come together in the right way. It might be more than just D6 to keep an eye on as well. There are a lot of pieces in play though so confidence seems low to me.

You often see hints of higher instability on the DGEX, but even that isn't much different than the GFS when comparing theta-e values.

There have been several estimates of the maximum wind speed put forth. The 494 page NIST report has a pretty thorough analysis of the event from pretty much every angle imaginable (I mean, it is 494 pages afterall). It looks like the estimates ranged from 170-230 mph with those on the lower end of that range being more realistic. The report said the EF5 rating was the result of the manhole covers and tractor trailers. Though I'm unsure what context the later is in reference to. I also read that the rebar anchored parking bumpers influenced the rating as well.

That spot in eastern Nebraska looks interesting on the 12Z GFS. The bulk shear is about 40 kts and nearly perpendicular to the boundary. There may be a short window of discrete supercellular activity. But the one thing that looks off is the 0-1km and 0-3km shear vectors are displaced to the east. It looks like convective activity will upscale quickly to an MCS and take advantage of an increasing nocturnal LLJ focused near or south of the NE/IA/MO border area.

In the context of this thread it may be good to note that there are apparently two different ways to calculate MUCAPE. 1. Lift each parcel level in the search layer (usually lowest 300mb) and perform the standard CAPE calculation. The level yielding the highest CAPE value will be the LPL and it's value is the MUCAPE. 2. Determine the wetbulb potential temperature at each level in the search layer. The level yielding the highest theta-w value is the LPL. Then perform a standard CAPE calculation. This value is the MUCAPE. The visual method is to plot the wetbulb temperature profile and then eyeball which level yields a Tw value that is furthest to the right in relation to the moist adiabats. The RAOB Program uses method #2 and I believe (someone correct me if I'm wrong) the SPC mesoanalysis also uses this method. In most cases method #1 and #2 will yield the same result. However, if there is an elevated inversion with a high relative humidity and that inversion is very deep then method #2 may yield a value that could much be lower than that from method #1. So why does method #2 even exist? I don't know really. Having written a program that generates soundings myself I can tell you that method #1 is computationally more expensive because the CAPE calculation must be performed at every level whereas with method #2 it is only performed at one level. The CAPE calculation itself is computationally expensive whereas theta-w may not be if the moist adiabat reference points are already present. So it's possible method #2 exists to speed up the generation of gridded products. I could be completely wrong though...just a guess on my part. Can any of you experts shed some light on this?