Like Jim, I am definitely impressed by the dry slot. When I saw that last night, I began to believe that a big event was going to take shape.
I really think that great 0-1 km shear will be present across the entire warm sector, despite the modest amounts of helicity forecast by the ETA. As of yesterday, the real wild card in this situation was insolation, IMO. However, cloud cover will not be a problem today, at least based on w/v imagery which clearly shows an area of mid-upper level subsidence moving over central and northeast Texas. Given this and very cold mid level temperatures, CAPE of 3000 j/kg should be realized.
The low level jet has formed, per the Palestine, Texas wind profiler (35 kts just above the sfc). Dewpoints are beginning to climb near the Gulf coast (already 70 at some sites) and should continue to do so throughout the day as strong warm air advection develops.
Barring storm mode problems (e.g. linearization of convection), I expect a tornado outbreak. There could be some particularly strong tornadoes given the extreme low level shear, large instability and low LCLs. Also, many of the tornadoes that form will likely be long trackers due to the fast wind speeds in the mid-levels.
Gabe