The image above is the sfc analysis at 2243Z yesterday as those three monster storms had just formed off of the dryline in northwest Kansas. the orange line is the dryline and the red line is the location of the warm front. The blue arrows depict the storm motion at the time. I think the biggest reason that there were no tornadoes ties in directly with what Dima (Dryline) was saying. The warm sector with temps above 70F and where the highest cape values (>2000 J/kg) was very modest in size. Each one of those supercells that formed off the dryline grew in a very favorable area to become tornadic; however based on storm motion they were not able to remain in the warm sector for very long before riding over the top of the retreating warm front and into much more stable boundary layer (Temps in the 50s/60s) even despite the strongly backed winds. Cape values to the north and east of the warm front where near 0 as Dima was saying and each one of those cells basically crapped out into a hail producer as they moved northeast into southwest Nebraska. The cells farther to the north seemed to be more dynamically driven and grew upscale as the shortwave was moving through (moving into more unidirectional shear) but again like the cells Dima was on to the south had no real chance at producing tornadoes.
It's tough to see such a favorable setup fail so hard. Storm motions would have had to have been much slower and more to the east, or if the cap could have broken earlier along the dryline while it was farther west across eastern Colorado. Anyways, I would say that was a pretty successful chase yesterday Dima and just a taste of whats to come for you the rest of this Spring into the upslope summer. Post some pictures when you get a chance.
Dan aka Squall Line
I completely agree with you. One positive factor that I noted when doing the analysis for this setup was the slow storm motions. This turned out to be the case, as I think those cells between Trenton, NE and McDonald, KS were moving at <30 mph, perhaps even 20mph for the Trenton one. If they had enough CAPE and were solidly rooted within the boundary layer, they should have been able to turn and move along the warm front (i.e. right movers). Because the CAPE was lacking, their updrafts were not strong enough to lower the pressure to their "right" and thus they were lifted above the warm front.
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