Storm Prediction Center Mesoscale Discussion 1686

   Mesoscale Discussion 1686
   NWS Storm Prediction Center Norman OK
   0700 PM CDT Thu Sep 02 2021

   Areas affected...portions of south central Nebraska into northern
   Kansas

   Concerning...Tornado Watch 487...

   Valid 030000Z - 030130Z

   The severe weather threat for Tornado Watch 487 continues.

   SUMMARY...A couple tornadoes and damaging gusts remain possible with
   the more sustained supercell updrafts over the next few hours.

   DISCUSSION...KUEX and MRMS mosaic radar data depict multiple
   supercells with transient low-level rotation in progress from
   Kearney to Harlan Counties in NE, with more isolated attempts at
   updraft intensification noted as far southwest as Gove County KS.
   These storms are moving into a partially modified airmass, where
   1500+ J/kg MLCAPE are common, but within a narrow corridor ahead of
   the storms. However 50+ kts of effective bulk shear and 200+ m2/s2
   effective SRH are present within this narrow corridor, which will
   promote additional instances of low-level rotation supporting brief
   tornado and damaging gust potential with the more robust,
   longer-lived supercells, especially along the KS/NE border.

   ..Squitieri/Guyer.. 09/03/2021

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

   ATTN...WFO...TOP...ICT...GID...LBF...DDC...GLD...

   LAT...LON   38650076 39569994 40619963 41319928 41509836 41169771
               40569751 39929767 39159810 38769847 38509910 38439966
               38420029 38650076