There are few days that ever are as big in chasing as this one would be (were I to be out). Textbooks will be written based on today's amazing setup, but it means bleak things for those who live in KS/OK.
At the time of this writing (1500 EST), the atmosphere has come alive and things will begin to unfold in a major and destructive tornado outbreak.
Here's the current visible satellite image:
You'll notice that there is a line of convective storms (hard-looking cumulus clouds) in the SW KS/TX & OK PH areas. This area is under incredible atmospheric cues that include: abundant moisture, abundant instability, abundant lift, and synoptic scale features (a triple point: the intersection of a dryline, low pressure system, and surface fronts).
Current surface winds are out of the south over the target area (an area about 50 miles west of I-35 between Wichita, KS, and Oklahoma City, OK). Early radar returns show that the cumulus clouds have rapidly ascended and already are producing rain and in some cases short-lived tornados. This is incredibly fast development and there is still about 8 hours of daytime sunlight to fuel these flames.
Amazing upper level support is moving over the area, and this region is in the left front exit region of a jet streak at 500mb.
The bottom line: this day falls under the term epic and sadly Wichita down to OKC look to be under a very threatening gun. Will update as time allows.
Latest 500mb analysis qualifies as "the perfect storm". Anticipate huge tornados will begin to form in the next hour or so with very large damage potential.