Mesoscale Discussion 2040
   NWS Storm Prediction Center Norman OK
   0838 PM CDT Sun Sep 29 2019

   Areas affected...eastern Wyoming...western South Dakota...and far
   northwestern Nebraska

   Concerning...Severe potential...Watch possible 

   Valid 300138Z - 300415Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Thunderstorm development is expected to increase across
   the eastern Wyoming/western South Dakota vicinity, with large hail
   likely to be the primary risk.  WW issuance may be needed.

   DISCUSSION...Latest radar shows convection developing across eastern
   Wyoming and western South Dakota, in the vicinity of a southeast
   Wyoming surface low.  A warm front extends east from the low,
   roughly along the Nebraska/South Dakota border, and model forecasts
   continue to suggest that storms will increase in coverage to the
   north of this boundary, as QG ascent gradually increases.  While
   timing of the onset of severe risk remains uncertain, ascent --
   evident within WV imagery -- continues spreading across central
   Wyoming toward the discussion area, which suggests gradually
   increasing potential for vigorous storms.  With moderate CAPE above
   700 mb and strong southwesterly flow aloft, supportive of rotating
   updrafts, potential for large hail is evident.  This may require WW
   issuance in the next hour or so.

   ..Goss/Guyer.. 09/30/2019

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

   ATTN...WFO...ABR...LBF...UNR...CYS...

   LAT...LON   42900534 43700517 44930406 45660286 45730164 45290048
               44490076 43620149 42770253 42480425 42900534