


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
667 ACUS02 KWNS 180555 SWODY2 SPC AC 180553 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Mon Aug 18 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A severe threat is not expected across the continental U.S. on Tuesday or Tuesday night. ...DISCUSSION... A mid-level ridge will build northward across the central Rockies and northern High Plains on Tuesday, as a subtle shortwave trough moves through the Great Lakes region. At the surface, a cold front will advance southward into the Ohio and mid Mississippi Valleys, extending westward into the southern Plains. As surface temperatures warm during the day, low-level convergence near the front will be favorable for isolated to scattered thunderstorm development. Limited large-scale ascent and weak deep-layer shear will be unfavorable for severe storms. Further northwest into the north-central states, moderate instability will be possible by Tuesday afternoon, mainly in the Dakotas. However, a severe threat is not expected due to limited large-scale ascent, minimal low-level convergence, and weak deep-layer shear. Elsewhere across the continental U.S., a severe threat is not expected Tuesday and Tuesday night. ..Broyles.. 08/18/2025 $$