ZCZC SPCSWOMCD ALL ACUS11 KWNS 131721 SPC MCD 131721 ALZ000-TNZ000-MSZ000-131945- Mesoscale Discussion 2065 NWS Storm Prediction Center Norman OK 1221 PM CDT Fri Sep 13 2024 Areas affected...Parts of AL into middle TN Concerning...Severe potential...Watch unlikely Valid 131721Z - 131945Z Probability of Watch Issuance...20 percent SUMMARY...The threat for locally damaging wind and possibly a tornado may increase into this afternoon. DISCUSSION...A remnant surface low is located over northern AR early this afternoon. An occluded front extends east-northeast of the low into western TN, then extends southeast as a stationary or warm front across parts of northern/central AL into western GA. Farther south, a cold front is moving across MS, with a surface trough/wind shift noted to the east from western AL into southern MS. In the vicinity of these boundaries, convection is gradually increasing from western AL into southern middle TN, and a few cells across northwest AL have exhibited some weak rotation. While low-level flow/shear has gradually decreased as the remnant of Tropical Cyclone Francine has weakened, effective SRH of around 100 m2/s2 and modestly favorable deep-layer shear will continue to favor occasionally organized convection into this afternoon. MLCAPE will increase to near or above 1000 J/kg, with an increase in convective coverage expected with time within a weakly capped environment. A few marginal supercells could evolve with time, and a tornado cannot be ruled out, especially in a zone between the surface trough/wind shift approaching from the west and the effective warm front to the east, where low-level flow will remain locally backed as gradual heating/destabilization continues. Otherwise, locally damaging winds will be possible, especially if any localized clustering of convection can develop with time. ..Dean/Gleason.. 09/13/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OHX...BMX...HUN...MOB...MEG... LAT...LON 32228565 31618689 31888728 32568749 34138797 34948822 35448837 35718835 35898821 36088759 36108707 35658637 33948592 32638572 32228565 NNNN