Day 4-8 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0346 AM CDT Tue Apr 14 2026 Valid 171200Z - 221200Z CORRECTED FOR DAY 5 GRAPHIC LABEL ...DISCUSSION... ...Day 4/Friday - Southern Plains to Upper Midwest... A strong upper trough oriented from Montana to the Southwest will eject eastward to the Plains on Friday/Friday night. Southwesterly mid/upper flow will intensify ahead of this feature, with 40-60 kt 850-700 mb flow forecast by late afternoon into the nighttime hours. A somewhat complex surface pattern is forecast, with a lee low deepening over the central/southern High Plains to western OK, and a second surface low near the Mid-Missouri Valley developing northeast into Ontario. A surface dryline will extend from the High Plains low to near the western OK/TX panhandle border into central TX by midday. Meanwhile, a cold front will be oriented from eastern MN into central KS at midday. Ahead of these surface features, a broad warm sector characterized by mid/upper 60s F dewpoints will be in place as temperatures warm into the 80s F. A plume of steep midlevel lapse rates will overspread the region, resulting in moderate to strong destabilization. Forecast soundings indicated impressive wind profiles supporting supercells. Initial supercell storms capable of all hazards (including very large hail and strong tornadoes) are expected. During the evening, convection may grow upscale into a squall line as storms near the Mississippi River, with an accompanying increase in damaging wind potential. ...Day 5/Saturday - Ohio Valley/Great Lakes vicinity... A severe risk will likely continue into Saturday as the upper trough continues to strengthen and shift east from the Plains to the Great Lakes/Midwest. Strong deep-layer flow parallel to an eastward-advancing cold front will overspread a moist and at least weakly unstable downstream airmass through evening. This will favor a line of convection with damaging wind potential. ...Days 6-8/Sunday-Tuesday... The surface cold front will continue east on Sunday, moving offshore the Atlantic and Gulf coasts during the afternoon. Severe potential appears limited by weak instability and mainly anafrontal precipitation across the Southeast to Eastern U.S. on Sunday. Surface high pressure and a dearth of boundary layer moisture in the wake of the cold front will preclude thunderstorm activity on Monday. By the end of the period, medium range guidance depicts another upper trough moving into the western U.S. and Gulf return flow will advect moisture back into the southern Plains. However, severe thunderstorm potential appears low at this time.Read more
