A southerly flow will be in place over the forecast area at the beginning of the period and brings increasing deep layer moisture in the area ahead of the approaching front, with surface dewpoints increasing to 65 to 68F and precipitable water values increasing to 1.5-1.8 inches. A series of shortwaves continues to move across the area Wednesday into Wednesday night as the front approaches resulting in broad and potentially strong deep layer lifting over the forecast area. SBCAPE values of 700-1000 J/kg will be present during peak heating on Wednesday and a 40-50 knot 850 mb jet results in 0-1 km Helicity values around 200 m2/s2. 0-6 km Bulk Shear values of 55-70 knots will also be present and supercell composite parameter values will be 5 to 8, indicating a significant potential for supercell development. Effective layer Significant Tornado Parameter values of 1.0-3.0 will also be present with the higher values over the southern and central portions of the area and also confined to mainly from mid Wednesday morning into Wednesday afternoon. This may change due to timing uncertainties, but considering all of these parameters for this environment, severe storm development looks possible including the potential for isolated tornadoes. The potential for severe weather development will wane Wednesday night with the loss of daytime heating, ending with the frontal passage. Another uncertainty is that the series of shortwaves moving across the region could result in a somewhat messy convective pattern, or organize into a quasi-linear convective pattern, but this will have to be ascertained later.

Models appear to favor a few convective scenarios which may play out on Wednesday with 1) initial storm development over LA near the boundary in proximity to stronger forcing to the west/northwest, and 2) potential warm-sector development farther east in southern MS in between I-10 and I-20 near a maritime front. Forecast hodographs vary slightly between different model guidance but a general supercell-wind profile would support the stronger warm-sector initiating storms to develop into supercells with all severe hazards possible. The strengthening 700-mb flow during the day lends some confidence in storm evolution featuring a mix of cells and convective bands. As storms move east during the evening and overnight, a gradual decrease in instability will probably favor the greatest severe risk becoming confined closer to the coastal plain as the activity moves into eastern AL/western GA and the FL Panhandle.

Some global consensus shows some potential for some coastal convection, but there remains a good feed of low-level Theta E across central to southwest Mississippi & northeast Louisiana to serve as an impetus for severe weather development along the Mississippi River around noon & to spread east-northeast through the afternoon to evening. Some hi-res guidance indicates even more concerning juxtaposition of parameters, with some experimental HRRR runs showing significant tornado parameter (STP) approaching 6+, bullseye over southwest Mississippi & northeast Louisiana & central portions of ArkLaMiss on the northern gradient & strong updraft helicity swaths. This environment will be very anomalously destabilized (i.e. 1000-1500+ MLCAPE) & sheared. Strong clockwise curving hodographs will lead to supercell & tornado potential, with some increasing potential for even more significant severe weather & upgrade in future outlooks possible. For now, in conjunction with SPC, expanded the "Slight" risk area for severe weather further northwest across the Delta, with "Marginal" risk area across the far northwest Delta. All modes of severe weather are possible, including damaging winds of 60-70mph, large hail of quarter to golf ball size & tornadoes. Keep a close eye on future outlooks for any increase in severe weather potential & upgrades in the HWO/graphics.

UNCERTAINTY REGARDING INSTABILITY AS WELL AS QUESTIONS CONCERNING THE POSITION OF THE FRONT AND ANY EFFECTS OF ANTECEDENT PRECIPITATION PRECLUDE INTRODUCING HIGHER SEVERE PROBABILITIES WITH THIS OUTLOOK.

12Z CAM SOLUTIONS SUGGEST THAT CONVECTION WILL FIRST FORM OVER CENTRAL LA AS THE LARGE-SCALE FORCING APPROACHES. LOW-LEVEL VERTICAL SHEAR WILL PROMOTE SOME RISK OF DISCRETE SUPERCELLS, ALONG WITH MORE COMPLEX BOWING STRUCTURES. FORECAST HODOGRAPHS INDICATE FAVORABLE PARAMETERS FOR A FEW TORNADOES, INCLUDING THE RISK OF STRONG TORNADOES, AS ACTIVITY BUILDS NORTHEASTWARD ACROSS THE ENH RISK AREA. DAMAGING WIND GUSTS AND PERHAPS SOME HAIL ARE ALSO POSSIBLE IN THE STRONGEST CELLS.