Mesoscale Discussion 0169
   NWS Storm Prediction Center Norman OK
   1113 AM CDT Thu Mar 12 2020

   Areas affected...Southwest MO/MO Bootheel...Southern IL...Western
   KY...Northwest/Middle TN

   Concerning...Severe potential...Tornado Watch likely 

   Valid 121613Z - 121815Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Ongoing thunderstorms as well as the potential for more
   storms this afternoon and evening will likely necessitate Tornado
   Watch issuance within the next hour.

   DISCUSSION...Cluster of thunderstorm currently ongoing across the MO
   Bootheel eastward into far northwest TN/far western KY has shown a
   general strengthening trend over the past hour or so. This cluster
   appears to have been initiated by the low/mid jet streak extending
   from eastern OK into northern AR/southern MO. This jet streak is
   expected to continue eastward throughout the day, providing both
   mesoscale forcing for ascent as well as enhanced low-level vertical
   shear. The ongoing cluster is evidence that the ascent is enough to
   lift parcels to their LFCs and the rotation noted in these cells,
   particularly those over the MO Bootheel and far northwest TN, is
   evidence of the enhanced vertical shear. 

   Expectation is for this cluster to continue northeastward/eastward.
   More eastward moving storms will maintain a closer proximity to the
   warm front extending across the region, resulting in access to
   greater low-level moisture and higher surface-based potential.
   Current surface analysis places the warm front from just south of
   the MO Bootheel east-northeastward to BNA. Primary threat with the
   elevated/more northeastward-progressing storms will be hail, but the
   more surface-based/eastward-progressing storms will also have the
   potential to produce damaging wind gusts and tornadoes. These
   threats will likely prompt watch issuance within the next hour.

   ..Mosier/Hart.. 03/12/2020

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

   ATTN...WFO...LMK...OHX...PAH...MEG...

   LAT...LON   36879049 37908922 38038715 37448592 36278671 35668807
               35719024 36879049