SPC AC 170552

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1252 AM CDT Tue Sep 17 2024

   Valid 181200Z - 191200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE GREAT
   PLAINS...

   ...SUMMARY...
   Isolated severe wind and hail are possible across a portion of the
   Great Plains during the late afternoon and evening on Wednesday.

   ...Great Plains...
   A vertically stacked cyclone over eastern MT at 12Z Wednesday should
   drift towards the ND/SK/MB border area. A mid-level jetlet of 50-60
   kt winds at 500 mb should be confined within the dry slot, near the
   ND/SD border area on Wednesday afternoon. A dryline should become
   established from the eastern Dakotas to the southern High Plains.
   Remnant convective outflows from overnight to decaying morning
   convection are expected in the confined moist sector ahead of the
   dryline. The primary cold front attendant to the cyclone should
   gradually push east in the Dakotas and eventually merge with the
   retreating dryline early morning Thursday. 

   Large-scale ascent ahead of the dryline appears nebulous for
   surface-based storms during the afternoon to early evening.
   Lingering outflows and areas of greater boundary-layer heating
   should serve to focus isolated thunderstorm development. Guidance
   varies greatly with placement of convection given the weak forcing
   for ascent regime. But with a confined plume of moderate MLCAPE from
   1500-2000 J/kg and 30-35 kt effective bulk shear, a conditional
   lower-end supercell environment will exist. Relatively warm
   mid-level temperatures will contribute to weaker lapse rates south
   of the Mid-MO Valley, likely being a mitigating factor to more
   robust updrafts where sustained storms can occur. The bulk of
   guidance, outside of the 00Z GFS and RRFS, suggest sustained storm
   development farther north will primarily be a result of low-level
   warm theta-e advection Wednesday night. As such, severe storm
   coverage will probably remain rather isolated.

   ..Grams.. 09/17/2024

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z