Convective Outlook
— Day 3
Enhanced Risk
Summary
Severe storms will be likely Sunday from portions of the central and southern High Plains into the Upper Midwest. Supercells capable of all hazards will be possible before upscale growth and an emerging damaging wind risk continues into the evening.
Synopsis and Discussion
An upper-level trough will begin to eject across the Intermountain West on D3/Sunday with a more subtle shortwave trough moving across the central Plains. As a result, deepening low pressure will develop across eastern Colorado/western Kansas with strengthening southerly flow and warm moist advection south of a warm front lifting northward into the northern Plains and upper Midwest. Early in the period, elevated storms will likely be ongoing across portions of Iowa into southern Minnesota. Scattered severe storms capable of all hazards will be expected to develop near the warm front/low across eastern Colorado into Nebraska and across southern South Dakota continuing into portions of the upper-Midwest along the cold front through the evening. A more isolated and conditional threat for severe storms will extend southward along the dryline from western Kansas into western Oklahoma.
Central Plains Into The Upper Midwest ?
Early day elevated convection is expected to move across portions of Iowa into the upper-Midwest. This will pose some risk for severe hail through the morning. Across the central Plains, strong daytime heating is expected to yield moderate to strong instability across much of the central Plains. This in combination with strong deep layer shear suggests a rather volatile environment, particularly across central Nebraska into southern South Dakota/northwestern Iowa. Guidance suggests that thunderstorms will develop across eastern Colorado into Nebraska by the afternoon. Initial thunderstorm development will likely be supercellular and capable of all hazards including large to very large hail, damaging wind, and tornadoes. As the front sags southward through the evening, eventual upscale growth into a squall line is expected by the evening. A strong 50 kt low-level jet will ramp up into the evening, which may support a continuing potential for tornadoes, some of which may be strong.
Western Kansas Into Western Oklahoma ?
A more conditional threat may extend southward along the dryline into western Kansas and western Oklahoma. Guidance suggests some signal for isolated supercells to develop along and east of the dryline Sunday afternoon. The environment here will conditionally favor large to very large hail, damaging wind, and perhaps a tornado or two with the strengthening low-level jet in the evening.
000 ACUS03 KWNS 150732 SWODY3 SPC AC 150731 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Fri May 15 2026 Valid 171200Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Severe storms will be likely Sunday from portions of the central and southern High Plains into the Upper Midwest. Supercells capable of all hazards will be possible before upscale growth and an emerging damaging wind risk continues into the evening. ...Synopsis... An upper-level trough will begin to eject across the Intermountain West on D3/Sunday with a more subtle shortwave trough moving across the central Plains. As a result, deepening low pressure will develop across eastern Colorado/western Kansas with strengthening southerly flow and warm moist advection south of a warm front lifting northward into the northern Plains and upper Midwest. Early in the period, elevated storms will likely be ongoing across portions of Iowa into southern Minnesota. Scattered severe storms capable of all hazards will be expected to develop near the warm front/low across eastern Colorado into Nebraska and across southern South Dakota continuing into portions of the upper-Midwest along the cold front through the evening. A more isolated and conditional threat for severe storms will extend southward along the dryline from western Kansas into western Oklahoma. ...Central Plains into the Upper Midwest... Early day elevated convection is expected to move across portions of Iowa into the upper-Midwest. This will pose some risk for severe hail through the morning. Across the central Plains, strong daytime heating is expected to yield moderate to strong instability across much of the central Plains. This in combination with strong deep layer shear suggests a rather volatile environment, particularly across central Nebraska into southern South Dakota/northwestern Iowa. Guidance suggests that thunderstorms will develop across eastern Colorado into Nebraska by the afternoon. Initial thunderstorm development will likely be supercellular and capable of all hazards including large to very large hail, damaging wind, and tornadoes. As the front sags southward through the evening, eventual upscale growth into a squall line is expected by the evening. A strong 50 kt low-level jet will ramp up into the evening, which may support a continuing potential for tornadoes, some of which may be strong. ...Western Kansas into western Oklahoma... A more conditional threat may extend southward along the dryline into western Kansas and western Oklahoma. Guidance suggests some signal for isolated supercells to develop along and east of the dryline Sunday afternoon. The environment here will conditionally favor large to very large hail, damaging wind, and perhaps a tornado or two with the strengthening low-level jet in the evening. ..Thornton.. 05/15/2026 $$