Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
876 ACUS03 KWNS 190731 SWODY3 SPC AC 190730 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 19 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS TO SOUTHWEST WISCONSIN... ...SUMMARY... A broad area of severe thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Damaging gusts, large hail and a few tornadoes are possible through Monday night. ...Synopsis... A negatively tilted upper shortwave trough is forecast to lift northeast from the central Plains to the upper Great Lakes on Tuesday. As this occurs, a belt of 50-70 kt 850-700 mb southwesterly flow will overspread the Lower MO Valley to Upper Michigan. At the surface, low pressure will deepen and shift northeast from eastern NE/KS during the morning, to Lake Superior by Wednesday morning. A dryline is forecast to extend southward across western OK into southwest TX and will develop east through the afternoon. Further north, a cold front will surge east across IA/northern MO during the evening, becoming positioned from Upper Michigan to northeast IL, then southwest to central OK/northwest TX by Wednesday morning. ...Lower MO Valley to Upper Great Lakes... A warm front will lift north across southern MN into northern WI ahead of the surface low during the day. To the east of the low and eastward-advancing cold front, a broad warm sector with mid/upper 60s F dewpoints is expected. A plume of steep midlevel lapse rates will overspread this moist boundary layer, aiding in moderate to strong destabilization. Initial supercells may be possible, posing a risk for all severe hazards. However, given strong forcing, both large-scale and along the advancing cold front, upscale growth into one or more linear bands/segments is likely. This may transition the main severe risk to swaths of damaging gusts by evening. ...Eastern KS/Southwest MO into OK/Northwest AR... Forcing will be weaker with southward extent into the southern Plains vicinity. However, a very moist and unstable airmass will be in place amid supercell vertical wind profiles. More isolated convection may develop along the dryline during the afternoon in Oklahoma, and along the southern extent of the synoptic cold front across eastern KS. This activity will pose an all-hazards risk, with some potential for upscale growth during the evening, especially with any convection moving out of eastern KS into southwest MO. ...Northwest TX vicinity... A conditional threat will exist southward along the dryline. Forcing will remain weak and capping may ultimately preclude thunderstorm development. Nevertheless, strong heating along the dryline and at least modest low-level convergence may be sufficient to allow for a storm or two during the late afternoon/early evening. ..Leitman.. 05/19/2024 $$