


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
483 ACUS03 KWNS 210730 SWODY3 SPC AC 210729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Aug 21 2025 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential currently appears low on Saturday. ...Parts of the Midwest/Lower Great Lakes into the south-central Plains... A mid/upper-level trough is forecast to gradually amplify across the north-central and eastern CONUS Saturday. A cold front will continue moving southeastward across parts of the Great Lakes/Midwest into the south-central Plains. Midlevel lapse rates along/ahead of the front will generally be weak, but low-level moisture will be sufficient for moderate buoyancy by afternoon. The strongest deep-layer flow/shear will located across parts of the central Great Lakes, but the convective signal in most guidance is rather sparse across this area, likely due to limited frontal convergence and very dry air aloft. The 00Z NAM is a notable outlier, depicting both a much slower front, and more substantial development along/ahead of the front during the afternoon and evening. Severe probabilities may eventually be needed if trends end up supporting more robust convection along/ahead of the front across the Midwest and Great Lakes. Farther southwest, isolated to widely scattered storms will be possible across parts of the Ozarks and south-central Plains. While a strong storm or two will be possible in this area, relatively weak deep-layer flow/shear and generally modest instability may tend to limit organized severe potential. ...CO Front Range and adjacent parts of the High Plains... Scattered thunderstorms will again be possible across parts of the CO Front Range and adjacent High Plains Saturday. While wind profiles will remain favorable for organized convection, with modestly elongated hodographs within the post-frontal regime, guidance generally depicts weaker midlevel lapse rates compared to previous days, especially across the High Plains. There may be a tendency for storms to remain confined to the higher terrain for much of the period, with uncertain severe potential. However, a marginal supercell or two with hail potential cannot be ruled out, and severe probabilities may eventually be needed for some part of this region, if trends support sufficient destabilization. ..Dean.. 08/21/2025 $$