Storm Prediction Center Mesoscale Discussion 1637

   Mesoscale Discussion 1637
   NWS Storm Prediction Center Norman OK
   0737 PM CDT Thu Jul 16 2026

   Areas affected...north-central North Dakota

   Concerning...Severe Thunderstorm Watch 491...

   Valid 170037Z - 170230Z

   The severe weather threat for Severe Thunderstorm Watch 491
   continues.

   SUMMARY...The risk for a brief tornado or two will exist for the
   next couple of hours with large hail and severe wind gusts remaining
   the primary hazards.

   DISCUSSION...Over the past 30 to 45 minutes, several storm mergers
   have occurred in Rolette County, leading to large updrafts
   exhibiting some supercell characteristics. Both radar data and
   mesoanalysis indicate the ongoing storms colocated with a
   north-northeast to south-southwest oriented boundary, and in the
   vicinity of a more northwest to southeast oriented outflow boundary.
   Ambient vorticity associated with those boundaries coincides with
   sizable 0-3-km CAPE, suggesting the potential for rapid updraft
   accelerations in the lower part of the storms. As such, the
   potential for a brief tornado or two may increase for the next
   couple of hours, before diminishing thereafter. Otherwise, the
   predominant hazards will be large hail and severe wind gusts.

   ..Mead.. 07/17/2026

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

   ATTN...WFO...FGF...BIS...

   LAT...LON   48360045 49080045 49249999 49149884 49069818 48489783
               47959802 47779919 48050002 48360045 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN