Storm Prediction Center Mesoscale Discussion 1262

   Mesoscale Discussion 1262
   NWS Storm Prediction Center Norman OK
   0319 PM CDT Thu Jun 12 2025

   Areas affected...Northern NE...Southern SD

   Concerning...Severe potential...Watch likely 

   Valid 122019Z - 122215Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Thunderstorms capable of large hail and damaging gusts are
   possible across northern NE and southern SD this afternoon and
   evening.

   DISCUSSION...Convective initiation is underway along a modest
   frontal boundary that extends from east-central SD through the NE
   Panhandle to a low over southeast WY. Despite lingering mid-level
   warm air, strong diurnal heating has largely eroded any convective
   inhibition, and low-level convergence along the boundary has
   fostered deepening cumulus (and at least one storm capable of
   lightning). Expectation is for thunderstorm coverage to increase
   within a narrow corridor along this boundary. Wind profiles, which
   are characterized by low-level south-southeasterlies and
   mid/upper-level westerlies, support the potential for supercells
   initially capable of large hail. The thermodynamic profiles become
   more conducive for strong outflow with western extent, and there is
   some potential for outflow-dominant storms to progress southward (or
   even southwestward) into more of north-central NE. Overall severe
   coverage is expected to be high enough to merit watch issuance.

   ..Mosier/Guyer.. 06/12/2025

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

   ATTN...WFO...FSD...ABR...LBF...UNR...CYS...

   LAT...LON   42580293 43720169 44359949 44609767 43579769 41820093
               41690248 42580293 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN