Wednesday morning update
We're finally well within the range of higher resolution models this morning, and the outlook is not great. Temperatures on Friday morning are likely to reach freezing levels in much of the Dallas area, and this should be just cold enough to allow sleet, snow, or freezing rain to stick to roads. Precipitation will occur between late Thursday morning and about sunrise on Friday. The latest models indicate that some or most of this will fall as snow and sleet, with the potential for significant accumulations. In short, I expect travel around the metroplex to be a mess on Thursday evening, night, and Friday morning. I would anticipate significant flight disruptions on Thursday, Thursday night, and into Friday morning. Conditions should improve by the middle of the day Friday.
The best-case scenario is that air temperatures are a bit warmer than currently forecast, allowing freeways to remain snow and ice free. (I.e. the surface of the roadways remains warm enough to melt anything that falls).
The worst-case scenario is a major winter storm that shuts down the metroplex on Thursday and much of Friday morning, possibly into the early afternoon.