####018002586#### ACUS01 KWNS 231624 SWODY1 SPC AC 231623 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Apr 23 2024 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHWEST TEXAS... ...SUMMARY... Isolated severe thunderstorms capable of producing large hail (potentially 2+ inch diameter) and gusts to 65 mph will be possible this afternoon and evening across northwest Texas. ...Northwest TX... Visible satellite imagery and surface analysis this morning indicate the initial stage of moisture return is occurring across the southern Great Plains in the wake of a frontal intrusion into the Gulf a few days ago. A mid-level ridge will increasingly become established across the central/southern Rockies and adjacent High Plains as a Great Lakes disturbance gradually becomes more displaced from the region. An associated cold front will move southward across KS/OK before eventually stalling tonight across southeast OK and northwest TX. Weak lee cyclogenesis will aid in maintaining a southerly low-level fetch across central into west TX as strong heating results in a sharpening dryline by late afternoon. Isolated thunderstorm development will be most probable near the triple point 20-22Z. Steep lapse rates coupled with adequate moisture (1500-2000 J/kg MLCAPE) and veering flow beneath moderate westerlies, will support an initial supercell mode. Isolated very large hail of 2-2.5 inches in diameter will be the main threat, along with a few 55-65 mph gusts. ...Northern IL/southeast WI/Lower MI late this afternoon/evening... Have not changed the existing outlook for this region due primarily to consistency in model data and the forecast conceptual model not deviating. Water-vapor imagery this morning shows a mid-level trough over the Upper Midwest and this will continue southeast into the central Great Lakes by mid evening. An associated surface trough will likewise move southeastward, and this trough will be preceded by a band of rain with minimal buoyancy. Behind the rain band, surface heating with steepening low-level lapse rates and cooling midlevel temperatures will support weak surface-based buoyancy just ahead of a secondary frontal surge. Some low-topped convection will be possible late this afternoon through late evening from northern IL/southeast WI into Lower MI. The stronger storms could yield a localized marginal hail/damaging wind threat. ..Smith/Moore.. 04/23/2024 $$