Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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387 ACUS01 KWNS 231644 SWODY1 SPC AC 231643 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1143 AM CDT Mon Sep 23 2024 Valid 231630Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OZARKS TO THE OHIO/TENNESSEE VALLEYS REGION... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. ..Guyer/Lyons.. 09/23/2024 $$