SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Sat Oct 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF WESTERN/CENTRAL KS INTO SOUTHEAST NE... ...SUMMARY... Isolated severe thunderstorms are possible over portions of the central Plains on Sunday, mainly during the late afternoon and evening. ...Synopsis... An initially vigorous mid/upper-level shortwave trough is forecast to gradually weaken as it moves quickly northeastward from the Dakotas into northern Ontario through the period. A relatively deep surface low will move northeastward in conjunction with this system, as a trailing cold front moves through parts of the central Plains into the Upper Midwest/Great Lakes. ...KS/southeast NE into the Upper Midwest/Great Lakes... It appears that the Dakotas shortwave trough will eject too early and too far north to have more than a glancing influence on late afternoon/evening storm development, though a strong storm or two cannot be ruled out in the morning with this system. In the wake of the ejecting shortwave, moderate to strong low/midlevel flow will remain in place along the frontal corridor. Low-level moisture will be modest at best (with dewpoints generally in the 50s to low 60s F), but relatively strong heating will result in MLCAPE increasing to 500-1000 J/kg (generally greater with southwest extent) by late afternoon/early evening. Diurnal storm development may remain relatively isolated, given the absence of stronger large-scale ascent in the wake of the ejecting shortwave. Convection is expected to increase in coverage through the evening near and just behind the front, aided by a southwesterly low-level jet. The greatest relative severe potential still appears to reside from west-central KS into southeast NE, where instability may be sufficient for at least transient storm organization in the presence of sufficient deep-layer shear. Localized severe gusts and possibly some hail could accompany the strongest storms. The Marginal Risk has been maintained across the region because of this potential, with only minor adjustments. Farther northeast, relatively strong low/midlevel flow and prefrontal heating/mixing will be favorable for gusty-wind potential into parts of the Upper Midwest/Great Lakes. However, with weak buoyancy and a tendency for the bulk of convection to be relatively late, damaging-wind potential remains too uncertain for probabilities at this time. ..Dean.. 10/04/2025
