Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
752 ACUS03 KWNS 280710 SWODY3 SPC AC 280709 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0209 AM CDT Tue Jul 28 2026 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE NORTHERN AND CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Sporadic occurrences of mainly damaging wind appear possible Thursday afternoon into night across the northern and central Plains into the upper Mississippi Valley Thursday afternoon into night. ...Synopsis... A series of vorticity maxima is forecast to pivot through the northern Plains and upper Midwest, within the northeast periphery of an upper high centered over the southern Rockies. At the surface, an area of low pressure initially over the western Dakotas will develop east-southeast to eastern SD or southern MN by Thursday night. Meanwhile, a trailing cold front will advance through the northern into central Plains. ...Northern and central Plains into the upper Mississippi Valley... Latest model guidance indicates the potential for multiple areas of showers and thunderstorms to be ongoing at 12Z Thursday, aided by forcing for ascent attendant to a lead disturbance aloft and low-level warm advection along a waning, nocturnal low-level jet. The extent and duration of the early-day convection will have implications for the degree of air mass destabilization by afternoon ahead of the cold front. Where stronger heating can occur, the presence of dewpoints in the 60s to low/mid 70s will yield a moderately to potentially strongly unstable air mass. However, vertical shear will tend to be limited by generally less than 30 kt of mid-level flow across the warm sector. Thunderstorms are expected to increase in coverage and intensity through the afternoon along the cold front as well as any residual outflow boundaries from the morning convection. The models suggest the potential for upscale growth into one or multiple cold-pool-driven MCSs with the primary hazard being damaging wind gusts. Only 5% total severe probabilities will be included in this forecast due to uncertainty in the preferred corridor(s) of greater air mass destabilization and resultant severe weather threat. An upgrade to a Level 2/Slight Risk may become necessary once those details become more clear. ..Mead.. 07/28/2026 $$