Mesoscale Discussion 1682
   NWS Storm Prediction Center Norman OK
   0128 PM CDT Thu Sep 02 2021

   Areas affected...much of central Nebraska into northern Kansas

   Concerning...Severe potential...Watch possible 

   Valid 021828Z - 022030Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Storms are expected to increase in intensity, possibly
   becoming severe by 21Z near a surface trough from central Nebraska
   into northwest Kansas. A few supercells will be possible, with a
   brief tornado or two.

   DISCUSSION...An area of rain and thunderstorms is expected to shift
   east out of central NE and KS, with heating and destabilization
   expected westward toward the surface trough. Convergence along this
   trough is currently supporting a low-topped line of convection
   across northern NE, but temperatures are currently cool extending
   east of this activity.

   Visible satellite imagery shows clearing across southwest NE into
   western KS, and this will likely support initiation near the surface
   trough after about 20-21Z. While surface winds are weak near the
   trough, strong boundary-layer flow will persist to the east, along
   with 30-40 kt 850 mb winds. Therefore, assuming air mass recovery
   late this afternoon, sufficient SRH will support a supercell threat
   with cells that form near the trough and proceed east. Objective
   analysis currently indicates 0-1 km values over 200 m2/s2. A couple
   tornadoes will be possible in a narrow zone where the surface warm
   nose and SRH gradient interface. Otherwise, a few severe gusts or
   low-end severe hail will be possible.

   ..Jewell/Grams.. 09/02/2021

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

   ATTN...WFO...GID...LBF...GLD...

   LAT...LON   39709889 39169964 39220045 39610082 40050101 40670089
               41470041 42479993 42729982 42899934 42839892 42619865
               42019853 40949865 39709889