Storm Prediction Center Mesoscale Discussion 240

   Mesoscale Discussion 0240
   NWS Storm Prediction Center Norman OK
   1155 PM CDT Sat Mar 14 2026

   Areas affected...Far northwest Iowa...southern Minnesota...and
   central Wisconsin

   Concerning...Heavy snow 

   Valid 150455Z - 151000Z

   SUMMARY...Heavy snow banding will become more prominent in the
   coming hours across extreme northwest Iowa, southern Minnesota, and
   into central Wisconsin. Snowfall rates will likely exceed 2 inches
   per hour within a narrow band across the region.

   DISCUSSION...An intensifying cyclone is apparent in surface
   observations over the central Plains as a prominent upper-level jet
   continues to push southeast. Recent VWP observations across the
   eastern Plains have shown a pronounced increase in low-level winds
   (upwards of 50-60 knots at 1 km AGL) within the developing warm
   conveyor belt of the emerging cyclone. Concurrently, an increase in
   precipitation is noted from southwest NE into southeast SD as the
   strengthening low-level winds augment isentropic ascent as well as
   low to mid-level frontogenesis. 

   In the coming hours, strong isentropic ascent and more focused lift
   within the frontogenetical circulation between 850-700 mb will shift
   east/northeast into southern MN and central WI as the surface
   cyclone begins to migrate east/northeast. Ascent through a deep
   layer, including through a somewhat shallow dendritic growth zone,
   will support a broad swath of heavy snowfall rates in excess of 1
   inch/hour. 

   A combination of focused ascent within a frontogenetical 700 mb
   deformation zone and periodic convective augmentation (8.8 C/km
   mid-level lapse rates were noted in an upstream 00z OAX sounding and
   should be advecting into the southern flank of the deformation zone)
   will likely result in a narrow corridor of snowfall rates between
   2-3 inches/hour. Based on a consensus of recent guidance, this band
   will most likely emerge across southern MN into central WI during
   the 07-11 UTC time frame and will likely persist well into the
   mid-morning hours.

   ..Moore.. 03/15/2026

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

   ATTN...WFO...MQT...GRB...DLH...ARX...MPX...DMX...FSD...

   LAT...LON   45338876 45318807 45178757 45028729 44778720 44338741
               44068759 44078813 44149025 44169073 44049130 43519322
               43169443 43079499 43159547 43409578 43699585 43969558
               44469481 44809414 45149324 45339221 45389097 45338876