Storm Prediction Center Mesoscale Discussion 1308

   Mesoscale Discussion 1308
   NWS Storm Prediction Center Norman OK
   0754 PM CDT Sun Jun 15 2025

   Areas affected...Northeast Colorado...far northwest Kansas...and
   much of western Nebraska

   Concerning...Severe Thunderstorm Watch 420...

   Valid 160054Z - 160230Z

   The severe weather threat for Severe Thunderstorm Watch 420
   continues.

   SUMMARY...Severe thunderstorms continue this evening. Large hail and
   damaging winds will be the main threat in the short-term with the
   wind threat becoming the predominant severe threat later this
   evening.

   DISCUSSION...Thunderstorms continue across portions of the Nebraska
   Panhandle and far northeast Colorado this evening. These
   thunderstorms continue to grow upscale into a linear MCS as they
   move east. Coincident with this, several estimated/measured wind
   reports greater than 60 mph have been reported across the Nebraska
   Panhandle within the last 90 minutes, including a measured 62 mph
   gust at the 3 WNW Brownson, NE mesonet site in Cheyenne County.
   Recent radar trends suggest increasing westerly flow beginning to
   impinge upon the thunderstorms across Morrill and Cheyenne counties,
   which may increase the potential for bowing structures over the next
   1-2 hours.

   The environment ahead of these storms is increasingly unstable as
   the storms approach the instability axis where most-unstable CAPE
   ranging from about 2000 J/kg across southern portions of the area to
   in excess of 5000 J/kg across the northern portion. Given
   effective-layer shear greater than 30 knots, the combination of
   instability and shear will support intense thunderstorm updrafts
   through the evening. 

   Additional intense/severe thunderstorms have developed across
   portions of Cherry County. Given the more discrete nature of these
   storms, large hail will likely be the main threat. These storms will
   likely begin to weaken with the loss of diurnal heating.

   ..Marsh.. 06/16/2025

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

   ATTN...WFO...GID...LBF...UNR...GLD...BOU...CYS...

   LAT...LON   41020402 43010403 43000021 42070015 42080027 40710020
               40700081 39560073 39560141 39140139 39120205 39020206
               39030315 39570317 39560365 40000368 40000413 40540414
               40560358 41000361 41020402 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN