Mesoscale Discussion 0484
   NWS Storm Prediction Center Norman OK
   1145 PM CDT Sun May 02 2021

   Areas affected...Portions of northern MS into northwestern AL

   Concerning...Severe potential...Watch possible 

   Valid 030445Z - 030645Z

   Probability of Watch Issuance...40 percent

   SUMMARY...An isolated tornado threat may persist overnight. Watch
   issuance is possible, but will depend on signs on increasing storm
   intensity.

   DISCUSSION...A long-lived, low-topped supercell that produced a
   tornado earlier in Tupelo MS has weakened somewhat as it has moved
   northeastward into northwestern AL and encountered a less unstable
   airmass, but it is still showing signs of occasional low-level
   rotation. Additional low-topped convection has formed in the past
   hour across parts of northern MS in a continued strong low-level
   warm advection regime. A low-amplitude shortwave trough is moving
   over the Mid-South now per recent water vapor satellite imagery.
   Ascent associated with this upper trough and the low-level warm
   advection will probably continue to support convection across
   northern MS and parts of northwestern AL through the early overnight
   hours. Deep-layer shear remains adequate for storm organization.
   Recent VWPs from KGWX show some veering of the 0-1 km flow in the
   past hour or so, and this trend should continue as the core of the
   low-level jet shifts eastward into AL/TN overnight. Still, low-level
   shear is expected to remain more than adequate for updraft rotation,
   with effective SRH around 200-300 m2/s2 likely to remain in place
   over this region for at least several more hours. Isolated tornadoes
   may occur if any of this ongoing low-topped convection can
   strengthen further. However, this potential appears uncertain given
   the weak instability in place and the stabilizing effects of earlier
   storms. Tornado Watch issuance is possible in the next couple of
   hours, but will largely be dependent on radar and observational
   trends.

   ..Gleason/Thompson.. 05/03/2021

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

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

   LAT...LON   33599090 34389054 34958895 34948781 34718762 33958774
               33708846 33329073 33599090