ACUS03 KWNS 210724 SWODY3 SPC AC 210723 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Sun Jun 21 2026 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered severe storms are expected across the central High Plains on Tuesday with isolated severe storms possible into the Upper Midwest. Large hail and damaging wind gusts will be the primary threats. ...Synopsis... A low-amplitude ridge across the western CONUS will build slowly northward as a trough moves south from Alberta into the northern Plains. As this pattern continues to evolve, mid-level flow will strengthen across the Rockies and into the Plains. This will result in strengthening lee cyclogenesis across the southern High Plains. Farther east, a cold front will move off of the East Coast during the day Tuesday. ...Central High Plains into the central Plains... Strengthening upslope flow to the north of the developing lee cyclone should result in storm development by mid-afternoon across eastern Colorado on Tuesday. As mid-level flow strengthens to near 50 knots, this strong shear combined with moderate to strong instability will support supercells capable of large to very large hail and some severe winds. Expect these supercells to eventually congeal into one or more clusters as they move east during the evening, with an increasing severe wind threat. ...Upper Midwest... A weak surface low associated with the mid-level trough moving south out of Canada will settle into the Upper Midwest on Tuesday. A cold front will extend southwestward from this feature with dewpoints into the low 60s ahead of it. This should produce sufficient instability for scattered storm development. Some damaging wind gusts may be possible with the strongest storms. ...Southeast... A cold front will move off the East Coast during the day on Tuesday. Most guidance shows the front offshore before sufficient instability develops for a severe storm threat along the Georgia, South Carolina, and North Carolina coasts. Therefore, have not added probabilities at this time. However, if the cold front slows or if greater instability develops than currently forecast, a Marginal Risk may be needed in later outlooks. ..Bentley.. 06/21/2026 $$