Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0344 AM CDT Sat Aug 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... Medium-range guidance is in good agreement that a shortwave trough will extend from southern Ontario southwestward into the Mid-South early D4/Tuesday morning. Surface low associated with this wave will likely be centered over the Lower Great Lakes, with an attendant front extending southwestward from this low into the central Carolinas. Some severe thunderstorms appear possible as the shortwave and related front move eastward/northeastward, but the best buoyancy will be displaced south of the strongest ascent, which could limit severe-storm coverage. There are some questions regarding frontal timing as well. These factors preclude introducing an area with this outlook. The progression of a strong shortwave trough from the northern Plains through the Upper Midwest, Upper Great Lakes, OH Valley, and into the Northeast looks increasingly likely from D5/Wednesday through D7/Friday. Some severe appears probable as the shortwave progresses eastward, particularly on D5/Wednesday across the Upper Midwest where mid 60s dewpoints will contribute to moderate buoyancy. Predictability issues become problematic after D5/Wednesday, with guidance differing on the strength/depth and speed of the shortwave.
