Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
428 ACUS03 KWNS 180728 SWODY3 SPC AC 180727 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CDT Sat May 18 2024 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA...KANSAS...SOUTHWEST IOWA AND NORTHWEST MISSOURI... ...SUMMARY... Severe thunderstorms are possible across parts of Nebraska and Kansas into western Iowa and northwest Missouri Monday afternoon into Monday night. More isolated strong to severe storms may extend into parts of the Middle Mississippi Valley and southern Wisconsin. ...Synopsis... An upper shortwave trough is expected to be located over the Lower MO Valley early Monday. This trough will lift northeast across the upper Great Lakes through Monday night. Meanwhile, a broad area of southwesterly flow will continued across the southern/central Plains east of a deepening upper trough over the western U.S. Deep-layer flow will become more amplified and stronger across the central Plains after 00z, as the western trough ejects east toward the High Plains by early Tuesday. At the surface, a cold front will be located from the eastern Dakotas into central NE. This front will continue to shift east through the evening before stalling from southern MN into eastern NE and central KS. Southerly low-level flow ahead of the front will result in a broad area of low to mid 60s F dew points from the Mid/Upper MS Valley into the central/southern Plains. ...KS/NE into southwest IA/northwest MO... Large-scale ascent will be nebulous through the afternoon, and capping will likely suppress convection through at least mid-afternoon. Thereafter, vertical shear will increase along with stronger ascent spreading into the Plains during the evening/overnight as the western trough ejects east. Thunderstorm clusters may initiate by early evening, with the potential for MCS development during the nighttime hours. Convective initiation and evolution is a bit uncertain given several rounds of convection expected for portions of the region prior to Monday evening. However, the overall large-scale pattern supports severe convection capable of all hazards into early Tuesday morning. ...Lower MO Valley to WI... Convection may be ongoing Monday morning from the MO River into central IA, northward into northern WI. How this convection evolves is a bit uncertain. However, some severe potential appears possible into the afternoon, as at least modest destabilization occurs amid somewhat favorable vertical shear. Hail and strong gusts will be possible with this activity through Monday evening. ..Leitman.. 05/18/2024 $$