Mesoscale Discussion 0778
   NWS Storm Prediction Center Norman OK
   0700 PM CDT Fri May 24 2019

   Areas affected...Portions of northeastern Iowa into southwest
   Wisconsin

   Concerning...Severe potential...Watch possible 

   Valid 250000Z - 250200Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A conditional threat exists for storms to mature over the
   next few hours. Storms that manage to organize and sustain
   themselves pose a risk for damaging wind gusts and perhaps a
   tornado. Convective trends are being monitored for a potential WW
   issuance.

   DISCUSSION...Convective initiation has recently transpired across
   parts of northeast Iowa, along and immediately north of a
   quasi-stationary baroclinic zone. Compared to areas farther south,
   northeast Iowa into southwest Wisconsin have experienced more cloud
   cover, inhibiting stronger diabatic heating (with temperatures only
   in the low to mid 70s) and associated boundary layer mixing.
   Nonetheless, at least modest buoyancy (1000-1500 J/kg MLCAPE noted)
   and favorable deep layer shear (50-60 knots of effective bulk shear)
   are in place. As such, storms that manage to mature may produce
   damaging wind gusts. Given the close proximity of storms to the
   baroclinic zone (with over 200 m2/s2 effective SRH noted), storms
   that manage to both mature and sustain themselves may be able to
   take advantage of the streamwise vorticity rich environment, and
   acquire low-level rotation, where isolated tornadoes would then
   become possible.

   Given the conditional nature of the threat, convective trends will
   continue to be monitored for signs of intensification and the
   subsequent need for a WW north of Tornado Watch 236.

   ..Squitieri/Grams.. 05/25/2019

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

   ATTN...WFO...LOT...MKX...DVN...ARX...DMX...

   LAT...LON   42279183 42419286 42889259 43409182 43689105 43268987
               42968907 42428923 42279183