Mesoscale Discussion 1198
   NWS Storm Prediction Center Norman OK
   1046 AM CDT Sun Jul 12 2020

   Areas affected...Much of central Alabama into northeast/east central
   Mississippi

   Concerning...Severe potential...Watch possible 

   Valid 121546Z - 121745Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Damaging wind potential with a southward advancing cluster
   of storms appears relatively low in the near term, but could
   increase more substantively across central Alabama and adjacent
   portions of Mississippi during the Noon to 3 PM CDT time frame. 
   Trends will continue to be monitored for the possibility of a severe
   weather watch.

   DISCUSSION...A sizable cluster of thunderstorms continues to advance
   across and south of the southern Tennessee border area.  This is
   occurring within 25-30 kt mean northwesterly ambient flow, ahead of
   larger-scale mid-level troughing digging across the Ohio Valley.  

   Much of the stronger convection appears supported by inflow of very
   moist boundary-layer air characterized by lower/mid 70s surface dew
   points, now extending in a relatively narrow plume across the lower
   Mississippi Valley into the southwestern flank of the convectively
   generated cold pool.  This appears to be contributing to large CAPE
   on the order of 2000-3000 J/kg, beneath modestly steep to steep
   mid-level lapse rates.  However, the stronger storms still appear
   rooted above the southern/southwestern flank of the southward
   advancing cold pool.

   Strongest storms, now southwest of Huntsville AL, appear near the
   intersection of the convective outflow and a southward extending
   wing of weaker convection probably supported by mid-level warm
   advection.  This may be just to the southwest of a developing
   mesoscale convective vortex, where it appears that strengthening of
   rear inflow is at least possible during the next few hours.  This,
   coupled with a gradual east-southeastward advection of the higher
   boundary layer moisture content and continued daytime heating across
   central Alabama, may result in increasing potential for severe wind
   gusts during the 17-20Z time frame.

   ..Kerr/Guyer.. 07/12/2020

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

   ATTN...WFO...BMX...HUN...MEG...JAN...

   LAT...LON   34198736 34168611 32478537 32118710 33668891 34618882
               34198736