SPC AC 131700 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Fri May 13 2022 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF LOWER MI AND THE OH AND TN VALLEYS...LOWER MS VALLEY...SOUTHERN HIGH PLAINS...AND CENTRAL PLAINS... ...SUMMARY... Strong/locally severe storms are expected across portions of the central third of the U.S. -- particularly from the Kansas/Oklahoma vicinity eastward toward the Ozarks. ...Synopsis... A mid-latitude cyclone is forecast to be in place over the Canadian Prairie Provinces early Saturday, with only modest northeastward progress anticipated throughout the day. A strong shortwave trough is expected to rotate through the base and eastern periphery of this cyclone, while another follows in its wake into the northern/central Plains late Saturday into early Sunday. Farther east, a large upper low is expected to weaken as it moves gradually eastward/northeastward into the Northeast. At the surface, a weak cold front is forecast to extend from Lower MI southwestward across southern IL, southeast MO, and northwest AR into southern OK. Some southeastward/southern progression of this front is possible throughout the day while it becomes increasingly diffuse. Another cold front is expected to drop across the northern Plains and into the Upper Midwest and central Plains. By 12Z Sunday, this front will likely extend from Lower MI southwestward into northern NE. ...Lower MI...Lower/Middle OH Valley...TN Valley... Scattered to numerous thunderstorms are anticipated ahead of the weak front mentioned in the synopsis. Dewpoints ahead of the front will be in the low to mid 60s, supporting moderate buoyancy. Vertical shear will be weak, limiting storm organization and promoting a multicellular storm mode. However, a few more robust updrafts are still feasible (particularly as a result of storm mergers), with isolated damaging wind gusts and/or hail possible. ...Lower MS Valley... Outflow from preceding thunderstorms may provide the impetus for additional early afternoon development across southern AR/northern LA. Uncertainty regarding the presence and location of this outflow limits predictability. However, if storms do develop, a few water-loaded downdrafts capable of isolated wind damage are possible. ...Central Plains... Elevated thunderstorm development is possible in the vicinity of the front over southern Nebraska Saturday night into early Sunday morning. Enough buoyancy and vertical shear will be in place to support isolated hail within the stronger updrafts. ...Southern High Plains... Afternoon heating/destabilization along a lee-trough/dryline will likely support very isolated storm development. Modest flow aloft should limit convective intensity overall, though a few stronger/high-based storms may produce gusty winds locally.