The National Weather Service has posted a Flood Watch for a large part of western and middle Tennessee and northern Mississippi valid until 6:00am Monday. A widespread 1 to 2 inches of rain, with some localized heavier amounts, has already fallen across the area, and the ground is pretty much saturated now. Additional moderate to heavy rain Sunday and especially Sunday night will lead to an increased risk for flooding, and even flash flooding if there are any storms that train over the same areas.
Drew mentioned in his morning weathercast that portions of the area had been placed in a Level 1 of 5 risk of severe storms for Sunday. That risk has now been expanded to include almost all of our viewing area. Aside from an elevated risk of flooding, the main threats from storms on Sunday will be that a few of them will be capable of quarter to half dollar size hail and wind gusts of 40-60 mph. While the tornado threat is not zero, and we can't rule out a stray tornado for sure, the overall risk of a tornado is low. However, we will still need to be on guard. Attached above is also a timeline for the risk of severe storms across the viewing area. Those time ranges are fairly large because this may come in multiple waves, with scattered storms in the afternoon and then a line of storms that moves southeast across the area during the evening and into the overnight. Below is a rough idea of how that evolution will play out, being shown on our high-resolution Baron Futurecast model:
Overall, the severe weather risk is relatively low, but it's not zero either. We have to be ready for maybe a few warnings (especially severe thunderstorm warnings) to be issued Sunday afternoon and evening. We will be staffed in the weather center and ready to provide live updates should conditions warrant that.