Storm Prediction Center Mesoscale Discussion 751

   Mesoscale Discussion 0751
   NWS Storm Prediction Center Norman OK
   0232 PM CDT Sun May 17 2026

   Areas affected...portions of central Lower Michigan

   Concerning...Severe potential...Watch possible 

   Valid 171932Z - 172200Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Thunderstorms may pose a risk for large hail and damaging
   wind gusts, with some potential for a tornado or two. Watch issuance
   is possible.

   DISCUSSION...Latest GOES water vapor imagery reveals an MCV over
   south-central Wisconsin, in close proximity to persistent elevated
   convection that has been ongoing through the morning and into the
   afternoon hours. Downstream of these features, latest surface
   analysis indicates a quasi-stationary surface boundary/warm front
   extending roughly west-east across central Lower Michigan with
   recent convective development noted north of Grand Rapids. South of
   this boundary, temperatures in the mid-80s and dewpoints in the low
   60s F are contributing 500 to locally 1500 J/kg MLCAPE. 35-45 kts of
   effective bulk shear (per latest mesoanalysis) is sufficient to
   support multicells/supercells with any convection that develops
   along/south of this boundary. This will promote the potential for
   large hail and damaging wind gusts with any sustained convection
   this afternoon.

   With time, a strengthening southerly low-level jet is forecast to
   yield an increase in low-level hodograph curvature into this
   evening, which would favor at least some increase in the threat for
   a tornado or two, particularly with any supercell/convection that
   can favorably interact with the warm front. Uncertainty remains
   regarding convective coverage and persistence within the warm
   sector, however. Trends will continue to be monitored, and watch
   issuance may eventually be needed.

   ..Chalmers/Mosier.. 05/17/2026

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

   ATTN...WFO...DTX...APX...GRR...

   LAT...LON   42718592 42888628 43378655 43828661 44218648 44508618
               44588460 44578373 44478329 44208285 43898253 43528246
               43198259 42958316 42808366 42728508 42718592 

   MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN