Mesoscale Discussion 0955
   NWS Storm Prediction Center Norman OK
   0219 PM CDT Sun Jun 21 2020

   Areas affected...portions of central/eastern Nebraska into far
   western IA

   Concerning...Severe potential...Watch likely 

   Valid 211919Z - 212115Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe thunderstorm potential will increase over the next
   couple of hours. Large hail (some 2+ inches) and damaging gusts will
   be the main hazards with convection through this evening.

   DISCUSSION...The airmass across central NE continues to recover from
   morning convection. While some isolated thunderstorms are occurring
   over northeast NE currently, these storms are probably somewhat
   elevated, residing atop the cooler/modified boundary layer. Further
   south, an ongoing cluster of storms across north-central KS may be
   inhibiting/slowing recovery somewhat as dewpoints have been slow to
   rebound and currently range from the upper 50s to mid 60s F.
   Additionally, cloud cover has persisted most of the day and
   temperatures are mostly in the 70s, with a few low 80s noted.
   Nevertheless, a plume of steep midlevel lapse rates stretches across
   the region and is aiding in MLCAPE values from 1500-3000 J/kg.
   Additional heating and modest increase in dewpoints, coupled with
   stronger ascent overspreading the region in the next couple of
   hours, should continue to erode capping and surface-based convection
   is expected by 21-22z along the southwest-northeast oriented surface
   boundary draped across the state. 

   Supercell wind profiles and elongated hodographs amid steep lapse
   rates will support large hail, some greater than 2 inches in
   diameter. Where stronger heating is resulting in steeper low level
   lapse rates, increased potential for strong downdrafts will exist,
   leading to locally damaging gusts. With time, more discrete
   convection may evolve into clusters and/or bowing segments toward
   evening, though the persistent cloud cover and subdued recovery
   across the region is resulting in greater uncertainty in convective
   evolution later this afternoon/evening. Regardless, severe storms
   are expected and a watch will likely be needed in the next couple of
   hours.

   ..Leitman/Guyer.. 06/21/2020

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

   ATTN...WFO...FSD...OAX...GID...LBF...

   LAT...LON   42879766 42979631 42839599 42499586 42019586 41619613
               41159659 40289814 40029872 40019930 40029969 40139995
               40870011 41350015 41749986 42339904 42669839 42879766