Storm Prediction Center Mesoscale Discussion 1378

   Mesoscale Discussion 1378
   NWS Storm Prediction Center Norman OK
   1007 PM CDT Thu Jun 19 2025

   Areas affected...Central to southern Nebraska

   Concerning...Severe potential...Watch unlikely 

   Valid 200307Z - 200500Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A lone supercell moving southward across central/southern
   Nebraska will likely continue to pose a very large hail/severe wind
   threat through at least 04-05 UTC. Watch issuance is currently not
   anticipated given the localized/isolated nature of the storm.

   DISCUSSION...A lone, but very intense, supercell has been ongoing
   across central NE over the past few hours with a history of
   producing 2+ inch hailstones and wind gusts upwards of 70 mph. The
   recent onset/strengthening of the nocturnal jet (very apparent in
   recent KUEX VWP observations) has regionally bolstered low-level SRH
   (upwards of 700 m2/s2 0-3 km SRH), which is very favorable for
   supercell maintenance despite the onset of nocturnal stabilization.
   Additionally, this cell is residing on the periphery of a reservoir
   of colder temperatures aloft over central NE that are supporting
   most-unstable lifted indices on the order of -8 to -10 C.
   Consequently, this cell will likely continue to pose a threat for
   very large hail (most likely 1.5-2.5 inches in diameter) and 60-70
   mph gusts for at least the next couple of hours as it approaches the
   I-80 corridor. Diminishing mid-level flow with southward extent
   should lead to a gradual reduction in storm organization/intensity
   as the cell moves into south-central NE later this evening, though
   the exact timing of storm demise remains uncertain given the
   well-established mesocyclone.

   ..Moore/Smith.. 06/20/2025

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

   ATTN...WFO...OAX...GID...

   LAT...LON   41469905 41659891 41719866 41639836 40749781 40439778
               40209800 40059828 40049856 40099887 40199914 40379920
               40689922 41469905 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN