Mesoscale Discussion 0618
   NWS Storm Prediction Center Norman OK
   0645 PM CDT Sat May 16 2020

   Areas affected...southern and central IA and far northern MO

   Concerning...Severe potential...Watch unlikely 

   Valid 162345Z - 170115Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A couple of strong storms could produce gusty winds or
   perhaps a brief tornado this evening. The overall threat is expected
   to remain very marginal, and a watch is not expected at this time.

   DISCUSSION...A surface trough extended from northeast KS into
   southeast NE and southwestern IA this evening, ahead of an upper
   shortwave trough tracking eastward across central ND/NE.
   East/southeasterly low level flow has transported low to mid-60s F
   surface dewpoints across the region. This has resulted in a modestly
   unstable airmass, with MLCAPE values as high as 500 J/kg (MUCAPE
   near 1000 J/kg). Backed low level flow in the vicinity of the
   surface trough is enhancing effective SRH and a couple of cells have
   shown brief rotation, with a funnel cloud reported in Cass County,
   NE around 2315Z. Aside from the enhancement to low level shear near
   the surface trough, effective shear is rather marginal across the
   region, around 20-30 kt. Modest shear in conjunction with modest
   midlevel lapse rates and weak instability should limit the overall
   severe threat. Nevertheless, a few strong gusts or brief tornado can
   not be ruled out with stronger cells. However, given the overall
   modest environment and transient nature of the threat, a watch is
   unlikely.

   ..Leitman/Hart.. 05/16/2020

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

   ATTN...WFO...DVN...DMX...EAX...OAX...

   LAT...LON   41829617 42059527 42119301 41969211 41839186 41239137
               40919136 40529160 40349257 40289447 40359520 40469591
               40979637 41449631 41829617