- Hazards: Damaging winds, flash flooding
- Threat Level: Marginal (Level 1/5)
Summary/Discussion: Expect a summer-like thunderstorm pattern to develop this afternoon. The enviornment is suitable for a few stronger thunderstoems will will have the possibility for damaging winds – and – given the heavy rainfall probability, instances of flooding will certainly be possible.
...Lower MS Valley/Mid-South... An MCV near the OK/AR border, that emanated out of a decaying MCS, should move east today overtaking/merging with a nearly stationary MCV in southeast AR. A confined belt of enhanced low/mid-level southwesterlies should be present this afternoon. However, destabilization will likely be more pronounced well south/southwest of the MCV track given how far south the large-scale convective outflow has surged in eastern TX and the Ark-La-Tex, in addition to weak mid-level lapse rates to the east. Still, have added a low tornado probability given the conditional risk. Otherwise, isolated damaging winds should be the main threat.
...Southern Plains into the Lower Mississippi Valley... Two distinct precipitation events will likely occur across the region through Tuesday morning, bisecting the expanded Slight Risk area. The first area of interest is related to the decaying MCS moving across southern OK/northern TX early this morning. The second area of concern is with respect to the MCV situated over central AR. Both of these area of ongoing convection will set the stage for convective development through the remainder of the forecaster period. A sharpening upper trough will pivot through the northern Plains into the Midwest/Great Lakes region. At the surface, a low will be migrating northeast from IA into MI with a cold front draped southwest into eastern KS, OK and across northern TX. Another shortwave moving through the central Rockies will emerge into the central/southern Plains late this afternoon, moving atop of the front and other residual boundaries left over from this mornings convection. This is one area of concern. Uncertainty remains with respect to where the front will be located, but also where the residual outflow boundaries will be positioned. This will play a role in where convection develops later in the evening and through the overnight hours. Model guidance varies on the evolution of convection; some solutions show little development (NMMB/HRRR), others show widespread convection across southeastern OK/northeastern TX (GEM/00Z HRRR) and one model illustrates multiple MCSs diving through TX (ARW). Regardless, the pre-frontal environment will be supportive of convective development if sufficient lift is present. MUCape climbing towards 3000 J/kg will provide sufficient instability for intense rainfall rates, especially when combined with precipitable water values of 1.75-2" surging northward aided by 20-30 knot low level flow from the Gulf of Mexico. Based on model continuity and ensemble support, it appears the best location for overnight development, thanks to the strengthening low level jet position, would be across northeastern TX/southeastern OK. However, again, this is highly dependent on the boundary/front positions and the mid-level shortwave. Areal average precipitation should be around 1-2+ inches with locally higher amounts expected. Rain rates could approach 2 inches/hour, though expect rates to generally stay below 1.5 inches/hour. Given this area has been worked over from numerous convective systems over the past several days, FFG is a bit lower in some locations. Therefore, this region is sensitive to additional heavy rainfall. While confidence is below average on convective development later tonight, enough model signal was present over saturated soils to expanded the Slight Risk area a bit farther west and south. The other area of concern is across portions of AR into far northwestern MS as the MCV decays through morning with the energy shifting east. Uncertainty also exists with regard to the trajectory for the energy which will certainty influence downstream convection during the afternoon. The axis of heavy rain may need to be lifted farther north or perhaps won't develop at all if blow-off cloud debris inhibits destabilization. Again, models are at odds with the evolution of afternoon activity. So the Slight Risk across AR accounts for the ongoing/decaying MCV and the expected convection farther east into northwestern MS that may fall over lower FFG.