Mesoscale Discussion 0315
   NWS Storm Prediction Center Norman OK
   1058 AM CDT Sun Mar 31 2024

   Areas affected...northern Missouri and adjacent portions of southern
   Iowa/northwestern Illinois

   Concerning...Severe potential...Watch unlikely 

   Valid 311558Z - 311830Z

   Probability of Watch Issuance...5 percent

   SUMMARY...An initial period of increasing thunderstorm development
   appears likely across parts of northern Missouri into southeastern
   Iowa and and northwestern Illinois his afternoon.  This may include
   strong thunderstorms posing a risk of severe hail for an hour or two
   early this afternoon across parts of northwestern Missouri, before a
   broader area of generally weaker thunderstorms evolves while
   spreading northeastward.

   DISCUSSION...Deepening convective development is evident within a
   narrow corridor, roughly west-northwest of the St. Joseph through
   Chillicothe MO vicinity.  This is rooted above a near-surface
   inversion layer, along/above a strengthening frontal zone, aided by
   ascent supported by weak to modest low-level warm advection.

   Beneath anticyclonic flow within the crest of broad mid/upper
   ridging east of the southern Rockies into the Appalachians,
   mid/upper support for convection, if any, appears subtle.  However,
   latest model output indicates increasing probabilities for
   thunderstorm initiation west-northwest through north of the
   Chillicothe vicinity by 17-18Z, where/when forecast soundings
   indicate modest conditional and convective instability in the
   presence of strong convective layer shear.  

   This environment may be conducive to the evolution of an initial
   supercell structure of two, which may pose a risk for severe hail. 
   Thereafter, guidance suggests warmer and more strongly capping
   elevated mixed-layer air will tend to gradually spread across and
   north of the surface warm frontal zone.  As this occurs, the warm
   advection driven convection, while perhaps becoming more widespread,
   may tend to become increasingly displaced to the north of the better
   instability near and south of the frontal zonal, resulting in
   diminishing risk for severe hail.

   ..Kerr/Thompson.. 03/31/2024

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

   ATTN...WFO...LSX...DVN...DMX...EAX...OAX...

   LAT...LON   39909505 40619549 40839287 40629147 40239104 39749232
               39739339 39909505