Mesoscale Discussion 1058
   NWS Storm Prediction Center Norman OK
   0717 PM CDT Mon Jun 21 2021

   Areas affected...Eastern Louisiana and central to southern
   Mississippi

   Concerning...Severe potential...Watch unlikely 

   Valid 220017Z - 220215Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A line of thunderstorms moving across the lower
   Mississippi River Valley may produce sporadic wind damage, but the
   overall severe threat will remain low enough to preclude the need
   for a watch.

   DISCUSSION...Regional radar imagery has revealed a gradually
   organizing line from western/central LA into western MS along and
   ahead of a southeastward moving cold front. Although GOES IR imagery
   shows a few stronger updrafts within the line, no wind damage or
   strong wind reports have been noted thus far. However, the line is
   moving into a corridor of higher low-level theta-e air and better
   instability (upwards of 2000 J/kg MLCAPE), which may support some
   intensification in the next 1-2 hours prior to the onset of gradual
   boundary layer stabilization due to the loss of daytime heating.
   Generally weak deep-layer shear is noted over the region, and a
   slightly stronger line-normal component to the mid/upper-level flow
   is allowing the LA segment of the line to propagate to the southeast
   faster than the MS segment. This section may present a better wind
   threat in the near term, though the axis of instability ahead of
   this section is rather narrow. Overall, the low probability for a
   substantial severe threat and limited spatial extent of the threat
   preclude a watch.

   ..Moore/Grams.. 06/22/2021

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

   ATTN...WFO...JAN...LIX...LCH...SHV...

   LAT...LON   31299298 31879246 32399205 32719102 33129024 33318967
               32968905 32508906 31888938 31309020 30979081 30939166
               30979233 31109289 31299298