Storm Prediction Center Mesoscale Discussion 1509

   Mesoscale Discussion 1509
   NWS Storm Prediction Center Norman OK
   0643 PM CDT Mon Jul 01 2024

   Areas affected...portions of eastern Nebraska into western Iowa

   Concerning...Severe potential...Watch likely 

   Valid 012343Z - 020115Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The severe threat will gradually increase as the warm
   front approaches and the low-level airmass destabilizes through the
   evening. Severe wind and hail are the predominant threats, though a
   tornado or two could also occur. A WW issuance will eventually be
   needed.

   DISCUSSION...Several thunderstorms are progressing eastward across
   NE, including a supercell that is traversing the warm frontal zone
   with a history of brief tornadoes. The surface warm front is
   expected to continue drifting northward with time as low-level
   warm-air advection increases in tandem with the strengthening of the
   low-level jet. Initially elevated buoyancy will advect over eastern
   NE into western IA with large, curved hodographs. The stronger,
   longer-lived updrafts that form should become multicellular and
   perhaps supercellular, capable of severe wind and hail. The tornado
   potential will be largely dependent on the degree of
   surface-based/boundary-layer destabilization can materialize this
   evening. A WW issuance will eventually be needed as storms across
   central NE impinge on the eastern bounds of Tornado Watch 496.

   ..Squitieri/Smith.. 07/01/2024

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

   ATTN...WFO...DMX...EAX...OAX...GID...

   LAT...LON   41649799 41939721 42029599 41889483 41509414 40929412
               40459464 40149553 40099625 40169697 40369766 41649799