Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Apr 22 2026 Valid 251200Z - 301200Z ...DISCUSSION... An active severe weather pattern will continue through early next week. On Saturday/Day-4, model guidance continues to show thunderstorms developing during the late afternoon and early evening hours along a lifting warm front across the Southern Plains. Along and south of this boundary, the environment will be strongly unstable with MUCAPE values between 2000-3000 J/kg as a low-level jet continually advects mid 60Fs dewpoints north across the boundary. Effective layer shear around 40 knots would support an initial supercell threat that should grow upscale into bowing segments overnight. A 30% area is introduced across southwest Kansas into east-central Oklahoma for the expectation is for strong bowing segments to move east-southeast overnight into a strong low-level jet. These storms will be capable of producing strong winds, large hail, and QLCS tornadoes. On Sunday/Day-5, ongoing convection across southeast Kansas and western Missouri at the start of the period may pose a continued risk of hail and damaging winds, and this convection may persist into mid morning. To the west, continued moist low-level advection will allow for surface dewpoints to rise into the upper 60Fs to low 70Fs across central Oklahoma to the east of a sharp dryline. At the same time, a low-amplitude shortwave should approach the Southern Plains during the late afternoon and evening hours, with a mid-990-millibar surface low developing across northwest Oklahoma along the dryline. The result of this setup will be a volatile atmosphere where MLCAPE values around 4000 J/kg exist within a strongly shear environment (vertical shear nearly 50 knots). Should thunderstorms initiate, a high-end severe weather threat could materialize during the late afternoon and evening hours across central and eastern Oklahoma and southern Kansas. However, global models continue to struggle to develop convection within this environment despite model guidance having modest upward vertical velocities overspreading the dryline. Pattern recognition suggests the need for a 30% severe area for this potential despite the lack of a QPF signal in the global models, and have opted to add one with this forecast. The location of this 30% will likely need to be refined in subsequent outlooks. The severe threat should continue into Monday/Day-6 across portions of the Lower Mississippi Valley. Strong storms should develop along and ahead of an eastward moving cold front. MUCAPE of 2000-3000 J/kg and 40-knots of deep-layer shear will support supercell thunderstorms capable of all severe hazards. The location, number, and intensity of these supercells will likely be modulated by the events of Sunday. Specifically, if widespread convection does not occur Sunday across the Southern Plains, a more robust reservoir of CAPE/lapse-rates will be available to thunderstorms across the Lower Mississippi Valley on Monday and a higher-end severe potential may develop. This will be monitored in subsequent forecasts. By Tuesday/Day-7 into Wednesday/Day-8, uncertainty in the severe potential across the southeast increases too much to have confidence in identifying specific locations. Although, as the mesoscale details become cleared in the preceding days, areas may need to be added in subsequent forecasts.Read more
