


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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365 ACUS01 KWNS 121251 SWODY1 SPC AC 121250 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Sat Jul 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE GREAT LAKES AND MIDWEST... ...SUMMARY... Scattered severe storms capable of damaging winds are expected across eastern Lower Michigan to the Lower Ohio Valley, mainly from mid-afternoon through sunset. ...Great Lakes/Midwest... An eastward-moving shortwave trough near the Manitoba/Ontario and Minnesota international border vicinity will overspread Lake Superior through late today into this evening while gradually taking on more negative tilt, with a convectively influenced perturbation ahead of it. Associated moderately strong westerlies will be relegated to portions of Wisconsin/Michigan, with sub-25 kt mid-level westerlies generally prevalent southward into the lower/middle Ohio River vicinity. Influenced by the lead shortwave trough, storm redevelopment may occur relatively early today across northern/eastern Lower Michigan, which could include some supercells. Primary storm development along an initial composite cold front/outflow is anticipated by mid to late afternoon from parts of eastern Lower Michigan towards the Wabash/Lower Ohio Valleys. Ample buoyancy (2000+ J/kg MLCAPE) will be prevalent ahead of this boundary despite warm mid-level temperatures. Unidirectional southwesterlies and nearly uniform wind speeds through the lower/middle troposphere will limit deep-layer shear and the degree of organized clustering. Still, the setup will be adequate for mainly a scattered damaging wind threat that will subside after sunset with storms lingering across Kentucky/Ohio. Isolated severe hail/damaging winds may also develop along the secondary cold front advancing eastward across northern/eastern Wisconsin and upper Michigan. Cooling mid-level temperatures will aid in weak MLCAPE of 500-1000 J/kg this afternoon. Westerly low-level wind profiles will modulate the degree of deep-layer shear and help to marginalize the overall threat. ...Southern Plains including Oklahoma and North Texas... Today`s severe risk will be influenced by multiple slow-east/southeast-moving MCVs that persist this morning across southwest Kansas and the Texas Panhandle. Storms will likely diurnally increase and intensify this afternoon across much of Oklahoma and a large part of north Texas. A modest MCV-related enhancement to the lower/middle tropospheric wind field may persist today, which could lead to some brief supercell structures and quasi-organized linear structures as mergers become more prevalent. Damaging winds and some hail may occur, and portions of the region will be reevaluated for a possible Slight Risk upgrade should confidence increase in a semi-focused corridor of severe potential this afternoon through early evening. ...Colorado/New Mexico... Modestly enhanced mid/upper-level north-northwesterlies over the higher terrain should aid in weak/transient updraft rotation as numerous cells develop during the afternoon. Isolated severe hail will be possible regionwide, with isolated severe gusts mainly across interior to southern New Mexico. ...Mid-South/Tennessee Valley to the Carolinas/Virgina... A pulse storm environment characterized by weak effective bulk shear but moderate buoyancy will support a threat for isolated wet microbursts from mid-afternoon to early evening, with tree damage possible. ..Guyer/Bentley.. 07/12/2025 $$