A well-defined upper low now over Nevada is continuing to move as expected (to the east). Increasing low-level moisture and lift as the low nears spells rain and thunderstorms by Thursday night/Friday. These may continue depending on the speed of the low and how much the first wave of storms stabilizes the air mass.
The rainfall map (above) suggests a round of heavy rain being the most likely scenario. Given the deluge we received Sunday, this additional rainfall will likely run off and may cause some minor to moderate flooding issues. Heaviest rain may be just south of Texoma but it's going to be a soaker at least.
On the other hand, area farms and ranches still have low stock tanks and this will help to fill them, so it’s likely to be a mixed blessing.
As for overall severe threat, it seems to be shrinking away a bit; dry air recirculating over the northern Gulf and then back through Texoma looks to keep surface dewpoints below the ideal severe threshold. Also, extensive cloud cover and possible rain-cooled air Friday would further serve to limit the more extreme severe potential. Since the upper low has cold air aloft, hail is once again the most likely severe element.
Of course, these systems are very dynamic, but a slight risk of severe seems to be the most Texoma is faced with at present.