Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
702 ACUS02 KWNS 161722 SWODY2 SPC AC 161721 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Jan 16 2025 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across the Lower Mississippi and Tennessee Valleys, and central Gulf Coast region Friday night into early Saturday morning. ...Synopsis... A short-wave trough digging southeastward out of western Canada across the north-central U.S. will partially phase with a second trough moving out of the Desert Southwest across the southern Plains, resulting in evolution of large-scale troughing across the CONUS. By Saturday morning, highly amplified cyclonic flow is forecast to encompass nearly the entirety of North America. At the surface, a deep cyclone associated with the upper troughing, initially over western Ontario, is forecast to occlude as it rotates northeastward across the James Bay area. A trailing cold front will sweep across the Plains/Upper Great Lakes/Midwest, and should reach a position from Lower Michigan southwestward to the Lower Mississippi Valley by 18/12Z (Saturday morning). ...Lower Mississippi Valley/central Gulf Coast area... As a cold front advances southeastward toward, and eventually into, the lower Mississippi Valley area, low-level warm advection atop a still cool/stable warm-sector boundary layer will lead to development of elevated convection, mainly during the second half of the period. As convection evolves, and low-level theta-e advection supports continued/modest elevated destabilization, a few thunderstorms will likely develop. While strengthening flow aloft during the period will result in shear that would otherwise support organized storms, the combination of a boundary layer not conducive for surface-based storms, and weak instability aloft, suggests that severe threat should remain no more than minimal at best across this region. ..Goss.. 01/16/2025 $$