Mesoscale Discussion 1403
   NWS Storm Prediction Center Norman OK
   1100 AM CDT Sat Jul 31 2021

   Areas affected...Southeast MO..Far Northeast AR...Extreme Far
   Western KY...Extreme Northwest TN

   Concerning...Outlook upgrade 

   Valid 311600Z - 311800Z

   SUMMARY...Potential severe threat associated with the ongoing
   convective line merits an upgrade to Slight Risk in the upcoming
   outlook across southeast MO. Trends are also being monitored for
   watch issuance.

   DISCUSSION...Recent radar and satellite imagery shows a somewhat
   steady-state convective line pushing southeastward across southeast
   MO at about 35 kt. Surface analysis places this convective line to
   north/northeast of a warm front extending from central MO
   southeastward into northwest TN. Based on current observations (in
   particular the LSX VAD) and modified RAP sounding, updraft bases
   within this convective line are likely elevated above the low-level
   stable layer. That being said, continued warming and moistening
   downstream should result in further reduction of the mixed-layer
   convective inhibition. As this occurs, some strengthening of the
   ongoing line is possible, although the overall convective evolution
   remains uncertain. One negative working against strengthening is the
   potential for some convective inhibition to remain, largely as a
   result of the warm mid-level temperatures. Conversely, the strong
   mid-level flow sampled by the LSX VAD as the system moved through
   suggests it may be organized enough to overcome the convective
   inhibition and re-intensify amid diurnal heating. 

   Despite the uncertainty, the threat this convective line could pose
   merits upgrading a portion of southeast MO to Slight Risk in the
   upcoming 1630Z. Additionally, trends are being monitored closely for
   potential watch issuance.

   ..Mosier/Grams.. 07/31/2021

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...PAH...MEG...LSX...LZK...SGF...

   LAT...LON   37369217 37869156 37909003 37168882 36198876 36159038
               36499244 37369217