SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Mon Oct 06 2025 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A couple stronger storms are possible over the southern High Plains and into the Midwest/Great Lakes today and tonight. However, widespread severe storms are not expected. ...Synopsis... In the mid-levels, a broad upper trough will continue eastward across southern Canada and the northern US while a weak positive-tilt perturbation will move eastward over the Rockies and northern Plains within a belt of enhanced southwesterly flow. At the surface, a cold front associated with the upper trough will move slowly east/southeastward, supporting scattered thunderstorms from the Great Lakes to the Southern Plains. While a few stronger storms are possible, minimal overlap of stronger buoyancy and vertical shear will largely preclude organized severe potential today and tonight. ...Southern High Plains... As the cold front continues south across the central and southern Plains, low-level easterly flow will increase over portions of eastern NM and west TX/OK. Weak upslope flow and diurnal heating of the modestly moist air mass should result in weak destabilization (MLCAPE 500-1000 J/kg) through the afternoon. This could support scattered thunderstorms (a couple of which may briefly be stronger) from eastern NM into the TX Panhandle and western OK. With 30 kt of deep-layer shear overspreading the area, multi-cell clusters capable of occasional strong outflow gusts are the primary risk. However, poor mid-level lapse rates, modest forcing for ascent and limited buoyancy suggest low storm coverage and limited potential for a more widespread and organized severe risk. ...Midwest to the central Plains... Along the cold front/surface trough, weak forcing ahead of an embedded shortwave perturbation within broad southwesterly flow aloft should support scattered thunderstorms by late afternoon from the central Plains to the Midwest. Surface heating along with modest dewpoints mostly in the 60s F will support modest buoyancy of 500 to 1000 J/kg, surface based ahead of the front and elevated along/behind it. A few stronger storms with damaging gust potential are possible across northern IL owing to 30-40 kt of effective shear oriented along the boundary. These storms may continue after dark into lower MI with sporadic damaging gust potential. However, the lack of more robust destabilization should limit storm organization/intensity. ..Lyons/Darrow.. 10/06/2025
