Mesoscale Discussion 1263
   NWS Storm Prediction Center Norman OK
   0116 PM CDT Sat Jul 18 2020

   Areas affected...Northeast Montana Central North Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 181816Z - 182015Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Isolated strong to severe thunderstorms will be possible
   by the mid to late afternoon hours, and may pose a threat for hail
   and strong winds. However, a watch is not expected due to the
   isolated nature of the threat.

   DISCUSSION...Recent visible and radar imagery from northeast
   MT/northwest ND and southern Canada show a few weak thunderstorms
   developing within a broader cumulus field as daytime heating and
   cooling temperatures aloft destabilize the environment behind a
   region of stratiform rain.  These elevated storms should mark an
   increasing trend in convective coverage through the mid to late
   afternoon hours as mid-level height falls overspread the region. The
   current environment over central to western ND shows sufficient
   parameter values for organized convection (upwards of 500 J/kg
   MLCAPE and 30-35 knots of effective bulk shear). However, the
   spatial overlap of these parameters is somewhat minimal as better
   instability under the main trough axis (where temperatures are
   cooler aloft) is displaced from the stronger flow to the southeast.
   Recent forecast guidance suggests that, despite a slight increase in
   MLCAPE through the day, the spatial overlap of CAPE/shear may remain
   limited. As such, the severe risk will be conditional on sustained
   convection residing within this favorable zone. If convection can
   become organized, it will pose a risk for severe hail and strong
   winds. Given the uncertainties regarding the coverage and duration
   of this threat, a watch is not anticipated.

   ..Moore/Hart.. 07/18/2020

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

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

   LAT...LON   48980495 48959995 48469915 47759866 47169871 46739932
               46559992 46490090 46560203 46720299 47130404 47710498
               48610528 48980495