Mesoscale Discussion 0447
   NWS Storm Prediction Center Norman OK
   0852 AM CDT Wed Apr 28 2021

   Areas affected...Portions of northern AR and southern MO

   Concerning...Severe potential...Watch possible 

   Valid 281352Z - 281545Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Some severe threat may continue this morning with a
   cluster of storms moving eastward, including the potential for
   damaging winds and a tornado. Watch issuance is possible.

   DISCUSSION...A loosely organized cluster of storms has developed
   this morning across northwestern AR and southwestern MO. VWPs from
   KLZK/KSRX indicate around 30-35 kt of 0-1 km shear is present, along
   with a favorable veering/strengthening wind profile with height
   through mid levels. Low-level rotation has been noted with a couple
   circulations within the line. An isolated tornado threat may
   continue through the morning across parts of southern MO and
   northern AR where rich low-level moisture, a weakly unstable
   airmass, and strong shear at low levels can support surface-based
   storms. Given the linear nature of the ongoing convection, damaging
   winds may be the primary severe threat. Filtered diurnal heating
   through a cloud deck downstream of this ongoing activity should
   support a gradual increase in boundary-layer instability over the
   next couple of hours. Although convective evolution remains somewhat
   uncertain this morning, downstream watch issuance may be needed if
   storms maintain their current intensity.

   ..Gleason/Hart.. 04/28/2021

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

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

   LAT...LON   35369122 35249244 35359364 35959328 36859321 36929183
               36849004 36178978 35549013 35369122