Mesoscale Discussion 0987
   NWS Storm Prediction Center Norman OK
   0307 PM CDT Wed Jun 24 2020

   Areas affected...northeast Washington...northern Idaho
   Panhandle...northwest Montana

   Concerning...Severe potential...Watch possible 

   Valid 242007Z - 242230Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Thunderstorm coverage is expected to increase across
   northeast Washington and into northwest Montana this afternoon.
   Severe hail/wind are possible with these storms. A watch issuance is
   possible and mostly depends on storm coverage.

   DISCUSSION...An upper-level shortwave trough is moving through the
   Pacific Northwest spreading forcing for ascent across the region and
   over the northern Rockies. A surface low is analyzed west of GEG
   with a surface pressure trough extending through eastern Washington.
   Storms have begun to develop over northeast Washington and northwest
   Montana across the higher terrain as terrain-induced circulations
   and surface dewpoints of 55-60 F have helped erode CIN and establish
   updrafts. Cold temperatures aloft have helped produce relatively
   steep lapse rates (7+ C/km) and MLCAPE of 1000+ J/kg. Strong, mostly
   unidirectional deep-layer flow has resulted in long hodographs and
   effective bulk shear of 35-45 knots. This could result in some
   supercell structures and upscale growth into a quasi-cluster is
   possible. As storms develop over the next 1-2 hours, large hail and
   damaging wind gusts will be possible. While a watch issuance is not
   anticipated at this time, convective trends will be monitored
   closely in case strong/severe storm coverage increases.

   ..Nauslar/Dial.. 06/24/2020

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

   ATTN...WFO...TFX...MSO...OTX...

   LAT...LON   49151522 49081338 48831309 48151339 47331467 47251673
               47961866 49031943 49061820 49151522