Below you can view a loop of model forecast Surface Relative Humidity. The blue colors are high, the yellows, greens, and reds are low. So what can you tell from this? As time progresses, you will notice that the line of blue quickly moves eastward, filled in by lower relative humidifies. This is the outline of the cold front that is passing through Texas tonight.
As you can see, most of the darkest blue indicates areas of potential rainfall...a fast-moving line impacting the majority of the state, but most notably the northern half, and east of the Interstate 35 Corridor.
Most of the severe thunderstorms expected will remain through the Panhandle, North Texas, Oklahoma, and eventually much of East Texas and Louisiana, although much of state of Texas is under-the-gun, even if just slightly. In fact, the majority of West Texas, including all of the Panhandle, as well as the Oklahoma Panhandle and western Kansas are all currently under a Tornado Watch, while East Texas, all of Louisiana, Arkansas, Mississippi, and much of Missouri, Illinois, and Western Tennessee are all poised with a flash flood watch.
Stay tuned to your local news channel and emergency management updates as this system continues to barrel down on the region.