


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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204 ACUS01 KWNS 211239 SWODY1 SPC AC 211238 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Mar 21 2025 Valid 211300Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast today. ...Synopsis... Within a largely zonal flow regime, embedded shortwave troughs will move from the Great Plains to the OH Valley, and inland over the Pacific Northwest and northern Rockies. The Great Plains trough will move over NE/IA by this afternoon/evening with an associated surface trough/weak cold front. Despite very limited low-level moisture, surface heating beneath cold midlevel temperatures (approaching -30 C at 500 mb) will allow for steep low-midlevel lapse rates and weak surface-based buoyancy this afternoon/evening. A few high-based, low-topped thunderstorms will be possible this afternoon through late evening. The steep lapse rates and moderately strong midlevel flow suggest some potential for gusty outflow winds and small hail/graupel with the convection, but the threat appears too limited to warrant severe probabilities. Otherwise, isolated lightning flashes will be possible later today into tonight from the WA Cascades into the northern Rockies. ..Thompson/Bentley.. 03/21/2025 $$