Storm Prediction Center Mesoscale Discussion 2021

   Mesoscale Discussion 2021
   NWS Storm Prediction Center Norman OK
   0925 PM CDT Mon Aug 17 2026

   Areas affected...portions of central into northern Nebraska

   Concerning...Severe Thunderstorm Watch 592...594...

   Valid 180225Z - 180330Z

   The severe weather threat for Severe Thunderstorm Watch 592, 594
   continues.

   SUMMARY...Severe gusts/hail remains possible with supercell
   structures, and a tornado may still occur with an intense supercell
   over Valley County. If storms in northern Nebraska can grow upscale
   into an MCS, an organized wind swath may occur.

   DISCUSSION...Multiple supercells continue to progress across central
   and northern NE with a history of severe gusts and occasional large
   hail. An intense right-moving supercell over Valley County, NE has
   also demonstrated periods of low-level rotation and remains capable
   of producing a tornado. In the immediate term, severe wind and hail
   (some significant) remains possible with any mature supercell
   structure given 3000+ J/kg MLCAPE and over 40 kts of effective bulk
   shear in place. KLNX radar trends show several supercell structures
   and accompanying outflow boundaries merging over central and
   northern NE. This is where several of the latest HRRR runs have also
   depicted upscale growth into a cold-pool-driven MCS. If this trend
   continues, an organized swath of strong to severe gusts may manifest
   over central into eastern NE over the next few hours. However,
   MLCINH will continue to increase through the evening. The current
   thinking is that storms that fail to grow upscale over the next few
   hours may begin to diminish with boundary-layer decoupling.

   ..Squitieri.. 08/18/2026

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

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

   LAT...LON   41620144 42470125 42970111 43120095 43080042 42819775
               42479732 41789732 41089775 40669905 40490028 40550091
               41000128 41620144 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN