Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Sat Apr 11 2026 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Isolated severe thunderstorms are possible from the southern and central Plains into the Upper Midwest on Sunday. ...Synopsis... An upper trough will slowly pivot east over the western U.S. on Sunday while upper riding envelopes the East. A couple of shortwave impulses will migrate northeast from the Plains to the Upper Midwest/MS Valley vicinity. Persistent midlevel southwesterly flow across the central portions will maintain lee troughing over the Plains. Meanwhile, southerly low-level flow will transport 60s F dewpoints northward from TX to WI ahead of a surface trough/dryline oriented across eastern NE into central KS, arcing south/southwest into northwest OK and western TX. A surface low is forecast to move across the Upper Midwest, where a boundary will be draped across southern MN into WI. ...Central/Southern Plains... Numerous showers and thunderstorms are likely to be ongoing Sunday morning across OK/TX, with more isolated activity possible northward into the Mid-MO Valley. This convection will have implications on airmass recovery and thunderstorm development along the dryline during the afternoon/evening. Some isolated wind/hail risk could accompany this early activity as clusters and/or line segments move across OK/TX during the morning. In the wake of this morning activity, persistent southwesterly mid/upper flow will maintain a plume of steep midlevel lapse rates and mixing near the dryline should erode cloud cover over portions of KS/OK/western TX. Large-scale ascent will remain nebulous, with a lack of height falls precluding large-scale support for thunderstorm development. Nevertheless, modest confluence along the dryline is forecast. Mid 60s F dewpoints beneath steep lapse rates will support up to 2500 J/kg MLCAPE. Furthermore, supercell wind profiles are apparent in forecast soundings. This environment will conditionally support supercells along the dryline by late afternoon into the evening. However, given a lack of forcing, storm coverage is uncertain. If storms can develop along the dryline, at least a narrow corridor of large to very large hail potential will exist in addition to damaging winds and a tornado or two. Some guidance suggests morning convection could intensify or redevelop across portions of north/central TX toward the ArkLaTex, but this scenario remains very uncertain. ...South Texas/Rio Grande vicinity... A conditional severe risk is apparent during the evening/nighttime hours. A moderately unstable airmass will be in place, though deep-layer flow will be somewhat weaker compared to further north. Nevertheless, some guidance suggests supercells will develop across Mexico and could approach/cross the Rio Grande during the evening. If this occurs, an initial risk for large hail and damaging gusts will exist. With time, some potential for clustering could occur and bring a continued risk for strong winds across portions of south-central/southern TX during the nighttime hours. ...Upper Midwest... Thunderstorm development during peak heating is uncertain. If the upper shortwave trough moves across the area too early, convective development may be limited in the wake of that feature. Nevertheless, a corridor of modest destabilization is expected ahead of the surface low as cool temperatures aloft support steepened midlevel lapse rates amid a moistening boundary layer. If storms develop, isolated severe hail and wind are possible with stronger storms. ..Leitman.. 04/11/2026Read more
