Well, very interesting. I just finished looking at today and tonight. Seems similar to what I said earlier however I think what has changed is the potential for convection to break out earlier - probably during the day whereas before I only thought at night. In particular I am talking southern OK and north Tx, although seems northern OK and further south in Tx may not be immune. I kind of like what SPC has graphics wise other than I would extend it at least 100 miles west and make the whole thing BIGGER!
The sfc low position in KS - true is further ne than previously expected - also the vort has slowed down and full strength won't arrive until early tomorrow probably before 12z, however models indicate that the low will elongate further sw and reform another low position in southern OK sometime overnight as the mid level low probably helps to create sfc cyclogenesis and back the winds. Further it appears we have clearing over Tx and Ok which will contribute to higher capes and less cinh. Looks like both NAM and RUC show cape further west than expected and remaining a bit longer. While cape is available further west than previous helicity seems to remain a bit further east of it for the most part. However they do intersect some and later after 0z they do substantially more in north Tx, and southern Ok.
Ruc shows convective precip breaking out today after 18z in Tx and along the Red and into Ok. If that verifies expect severe weather - this should be combined possible mid level divergence and a small wave during day to assist per NAM including day time heating.
Looking at forecast parameters - many of these RUC based and NAM based show quite a bit of severe activity all across northern Tx, Ok. Couldn't help but notice some huge tornadic indicators in southern IA, ne NE, northern MO. Not sure if that will verify but very interesting.
I still think the daytime convection is a bit questionable, but not nearly as much as previous. NAM EHI readings top out over 2 in Tx.
Where to go? Good question. Somehow Wichita Falls comes to mind, or perhaps a bit south east of there. Alternative would maybe be Ardmore to start the chase.
EDIT: I didn't realize SPS was so far west (too far IMO). I'd say east of there toward Gainseville - south and north of there instead.
END EDIT.
Tonight I expect severe to continue to ramp up, main wave arriving before 12z. Tomorrow may be interesting. If the low can reform and anchor further west without losing dewpoints in Tx - and wait for the vort max - look out and I would even be able to chase tomorrow. But probably somehow the dewpoint and westerlies will already be across most of Tx on Thurs. Will probably have to go at least to LA border to catch anything. That or HOU.
Now time to monitor via SPC Mesoanalysis.
. SPC upgraded to Moderate in that area for primarily after 0600 UTC for possible strong tornadoes ahead of and in embedded supercells in a rip-snorting squall line. Plus, it's in the jungle 
