Mesoscale Discussion 1736
   NWS Storm Prediction Center Norman OK
   0254 PM CDT Wed Aug 14 2019

   Areas affected...Portions of southeastern WY...western NE...and
   eastern CO

   Concerning...Severe potential...Watch possible 

   Valid 141954Z - 142200Z

   Probability of Watch Issuance...60 percent

   SUMMARY...A gradual increase in an isolated severe risk should occur
   this afternoon. Large hail, damaging winds, and perhaps a couple
   tornadoes will all be possible. Watch issuance may be needed by 22Z
   (4 PM MDT).

   DISCUSSION...Cumulus is slowly building across the Laramie Mountains
   of southeastern WY and the Front Range in northern/central CO.
   Current expectations are for convective inhibition to gradually
   erode through the remainder of the afternoon across eastern CO,
   southeastern WY, and parts of western NE. 19Z surface analysis shows
   a weak surface low over southeastern WY, with a front extending
   southeastward from this low across the central High Plains. Surface
   dewpoints across this region are several degrees lower than
   yesterday, generally in the mid to upper 50s, but up to the lower
   60s along and just north of the surface boundary. Still, steep
   mid-level lapse rates emanating from the Rockies have overspread
   this area, which coupled with strong diurnal heating will likely
   support 1500-2500 J/kg of MLCAPE through peak heating.

   With modestly enhanced northwesterly flow persisting aloft,
   large-scale forcing for ascent will remain nebulous across the
   central High Plains this afternoon. This lends some uncertainty
   regarding overall storm coverage. Isolated storms should eventually
   form over the higher terrain and slowly move east-southeastward.
   Additional convective development may occur with weak low-level
   convergence along the surface boundary extending into parts of
   western NE. Rather weak low-level flow is expected to persist
   through the early evening, but northwesterly flow does increase
   above 3 km, which is promoting around 35-45 kt of effective bulk
   shear. The presence of steep mid-level lapse rates, moderate
   instability, and enough shear to support supercells suggests
   isolated large hail should be the primary threat initially. Very
   large hail, potentially in excess of 2 inches in diameter, could
   occur with the strongest storms. A couple of tornadoes may also be
   possible along and immediately to the cool side of the front where
   low-level flow is backed to southeasterly, locally augmenting
   effective SRH. Depending on observational trends, a watch may be
   needed for some part of this area by 22Z.

   ..Gleason/Grams.. 08/14/2019

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

   ATTN...WFO...LBF...GLD...PUB...BOU...CYS...

   LAT...LON   41040470 41460487 42320535 42540521 42660469 42640404
               42080273 41170177 40200142 39510138 38960163 38490213
               38350319 38420426 38710465 41040470