SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Sun Oct 05 2025 Valid 052000Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible over portions of the central and southern Plains late this afternoon and evening. ...20Z Update... The only change with this update was a minor southward expansion of the MRGL risk area into the OK/TX Panhandles. Here, the latest surface observations indicate middle 50s dewpoints ahead of the front, which should support sufficient surface-based buoyancy for an isolated/brief strong-severe storm risk -- given 30-40 kt of effective shear and a nocturnally strengthening LLJ. Marginally severe hail and locally damaging gusts are the primary concerns with any sustained storms this evening. Elsewhere, the forecast remains on track. See the previous discussion below for details. ..Weinman.. 10/05/2025 .PREV DISCUSSION... /ISSUED 1122 AM CDT Sun Oct 05 2025/ ...Upper Midwest into the Central Plains... Within large-scale upper troughing over much of central Canada and the western CONUS, an embedded mid-level shortwave trough over the northern Plains will advance northeastward today into western Ontario. At the surface, low pressure will similarly track northeastward, while a cold front continues to advance south-southeastward over the Upper Midwest and central Plains through this evening. While mid 50s to low 60s surface dewpoints are expected to be in place ahead of the front this afternoon, warm temperatures/poor lapse rates aloft will hinder the development of any more than weak instability. Current expectations are for thunderstorms to develop late this afternoon/early evening along much of the length of the front from western WI/southern MN southwestward to western/central KS as a southerly low-level jet gradually strengthens. Most of this activity will be quickly undercut given enhanced mid-level flow aligned largely parallel to the front. Even so, some potential for strong to locally severe thunderstorms remains apparent across parts of KS into southeast NE and southwest IA, where convection may have a better chance to remain surface based for a couple of hours after initiation. Isolated hail and severe gusts should be the main threat with this activity before it eventually weakens later this evening. ...Central Gulf Coast States... Loosely organized convection is ongoing late this morning offshore from the central Gulf Coast in association with a weak mid/upper-level trough over the northern Gulf. Modest low/mid-level flow should limit thunderstorm organization, but occasional/weak low-level rotation has occurred with cells south of the FL Panhandle. With east-northeasterly low-level flow expected to persist along the coast, overall severe potential over land appears too low to include any severe probabilities.
