Storm Prediction Center Mesoscale Discussion 1436

   Mesoscale Discussion 1436
   NWS Storm Prediction Center Norman OK
   0611 PM CDT Sat Aug 07 2021

   Areas affected...Parts of southeastern Nebraska...western and
   central Kansas and adjacent portions of the Oklahoma

   Concerning...Severe Thunderstorm Watch 412...

   Valid 072311Z - 080115Z

   The severe weather threat for Severe Thunderstorm Watch 412
   continues.

   SUMMARY...An eastward advancing corridor of increasingly widespread
   thunderstorm development is expected through 7-9 PM CDT, with strong
   to locally severe wind gusts becoming an increasing hazard.  Trends
   are being monitored for the possibility of one or two additional
   severe weather watches.

   DISCUSSION...Stronger surface heating and deeper boundary-layer
   mixing is focused near the pre-frontal surface trough axis across
   the Texas/Oklahoma Panhandle vicinity through the Garden City/Dodge
   City areas, into north central Kansas northeast of Hayes and
   Russell.  However, the bulk of ongoing thunderstorm development has
   been occurring ahead of the cold front through areas west of the
   surface trough axis, where higher surface dew points and cooling
   aloft ahead an approaching short wave trough area contributing to
   greater CAPE (in excess of 1500 J/kg). Beneath 30-40 kt
   southwesterly mid-level flow, deep-layer shear is also strong,
   contributing to supercell structures north of Garden City.

   However, deepening convective development is evident near the
   immediate vicinity of the surface trough, and models suggest that a
   combination of consolidating convectively generated cold pools and
   the cold front will overtake the surface trough during the next few
   hours.  Aided by forcing for ascent and cooling aloft associated
   with the eastward progressing short wave trough, it appears that
   destabilization along the surface trough may support increasingly
   widespread thunderstorm development during the next few hours.  By
   01-02Z, there is some consensus among the various model output that
   this probably will extend from southeast of Dodge City through the
   Concordia and Hastings/Grand Island vicinities.

   Coinciding with nocturnal southerly low-level jet strengthening
   along this corridor (including 30-40+ kt at 850 mb), strong surface
   gusts approaching and occasionally exceeding severe limits will
   likely become the most prominent severe hazard.

   ..Kerr.. 08/07/2021

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

   ATTN...WFO...OAX...TOP...ICT...OUN...GID...DDC...AMA...

   LAT...LON   37570071 39259933 40489874 40859624 39469658 36909913
               36270034 37570071