Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
698 ACUS02 KWNS 270522 SWODY2 SPC AC 270520 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 AM CDT Tue Oct 27 2026 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential appears low on Wednesday. ...Mid-MO to Upper MS Valley... A midlevel trough will move from the High Plains to the Upper MS Valley on Wednesday. This will bring enhanced mid/upper southwesterly flow across the Mid-MO to Upper MS Valley atop modestly increasing boundary layer moisture. Vertically veering wind profiles and effective shear values greater than 35 kt typically could support supercell thunderstorms. However, surface-based thunderstorm develop appears quite conditional. Surface dewpoints in the 50s to near 60 F will be possible ahead of a surface boundary from southern MN into western IA and far eastern NE. Cool temperatures atop the modest boundary layer moisture will support MLCAPE values around 1000 J/kg. Near neutral height tendencies are expected, and forecast soundings indicate poor low-level lapse rates and possible inhibition in layers between the surface and 750 mb. Furthermore, 00z HRRR/RRFS and HREF/REFS do not show a robust signal for sustained convection within the more favorable warm sector. While elevated storms could pose a risk for small hail, the overall risk appears limited in the absence of surface-based storms, precluding severe probabilities at this time. Depending on trends, probabilities could be included in subsequent outlooks. ...Far SW TX vicinity... Isolated thunderstorms may develop near higher terrain within a modest upslope flow and low-level warm advection regime late Wednesday afternoon/early evening. Surface dewpoints in the mid/upper 50s will aid in modest destabilization as temperatures warm into the upper 70s/low 80s F. Deep-layer flow is expected to be weak, but vertically veering profiles will support around 20-25 kt effective shear magnitudes. A couple of storm could briefly become strong and produce gusty winds given steepened low-level lapse rates or small hail. Overall, severe potential appears too limited to include probabilities. ..Leitman.. 10/27/2026 $$