Storm Prediction Center Mesoscale Discussion 1304

   Mesoscale Discussion 1304
   NWS Storm Prediction Center Norman OK
   0300 PM CDT Mon Jun 17 2024

   Areas affected...Southern/Eastern WI

   Concerning...Severe potential...Watch possible 

   Valid 172000Z - 172200Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Thunderstorms capable of isolated hail and/or damaging
   gusts are possible across southern WI this afternoon and evening.
   Trends will be monitored for possible watch issuance.

   DISCUSSION...Temperatures have warmed in the upper 80s/low 90s
   across southern WI/eastern WI, amid dewpoints in the upper 60s/low
   70s. These very warm and moist surface conditions are helping
   support strong buoyancy, despite relatively poor lapse rates across
   the region. Recent mesoanalysis estimates MLCAPE is around 2000 to
   2500 J/kg, with little to no convective inhibition. Low-level
   convergence along and ahead of a stationary boundary extending from
   OCQ (about 30 miles north-northeast of GRB) southwestward through
   LNR in far southwest WI is contributing to convective initiation
   within this unstable airmass. Vertical shear is modest across the
   region, with effective bulk shear less than 20 kt. This lack of
   stronger shear is expected to promote a predominantly multicellular
   mode, but a few updrafts could still become strong enough to produce
   severe hail and/or a strong, water-loaded downburst. Overall
   coverage of severe is currently expected to remain isolated,
   limiting the need for a watch, but convective trends will be
   monitored closely.

   ..Mosier/Gleason.. 06/17/2024

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

   ATTN...WFO...GRB...MKX...ARX...

   LAT...LON   42619033 42979067 43759005 44508922 45008830 44688754
               44238745 43648768 42908779 42608825 42548939 42619033