Storm Prediction Center Mesoscale Discussion 1666

   Mesoscale Discussion 1666
   NWS Storm Prediction Center Norman OK
   0648 PM CDT Sun Jul 19 2026

   Areas affected...Parts of central ND into north-central SD

   Concerning...Severe Thunderstorm Watch 499...

   Valid 192348Z - 200145Z

   The severe weather threat for Severe Thunderstorm Watch 499
   continues.

   SUMMARY...The risk of severe wind gusts and large hail will continue
   to increase in coverage over the next couple of hours -- within
   Severe Thunderstorm Watch 499.

   DISCUSSION...Over the last 30 minutes or so, an increase in
   thunderstorm intensity and coverage has begun, as storms impinge on
   a plume of lower 70s dewpoints and at least 2000 J/kg MLCAPE per
   modified 18Z BIS sounding and the latest HRRR SFCOA data. As storms
   continue spreading/developing eastward, increasing buoyancy will
   support further intensification of ongoing storms. The BIS VWP is
   sampling a long/straight hodograph (40-50 kt of 0-6 km shear), which
   will continue to promote splitting supercells capable of producing
   severe wind gusts and large hail. Resultant storm mergers and
   increasingly robust outflow will favor a gradual increase in both
   the coverage and intensity of severe wind gusts over the next couple
   of hours.

   ..Weinman.. 07/19/2026

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

   ATTN...WFO...FGF...ABR...BIS...UNR...

   LAT...LON   47139897 46579914 46179935 45689978 45210059 45150109
               45200168 45470199 45740204 46370176 47650092 47900030
               47899964 47699913 47139897 

   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN