Mesoscale Discussion 2069
   NWS Storm Prediction Center Norman OK
   0540 PM CST Tue Dec 28 2021

   Areas affected...Northern Wisconsin into northeast Minnesota

   Concerning...Heavy snow 

   Valid 282340Z - 290345Z

   SUMMARY...Snow banding is probable over the next few hours across
   northern Wisconsin into northeast Minnesota. Moderate to heavy
   snowfall rates up to 1 inch/hour are possible. Lake-enhanced
   snowfall is also likely along the North Shore of MN.

   DISCUSSION...Regional radar mosaics over the past hour have shown a
   gradual weakening of the stratiform precipitation over
   central/southern WI with a corresponding increase across northern
   portions of the state into northeast MN. Surface observations under
   this precipitation show occasional visibility reductions to 1/2 to
   1/4 mile. This uptick in snowfall is likely the result of increasing
    ascent ahead of an approaching vorticity maxima (noted in
   water-vapor and radar imagery over south-central MN), as well as
   more focused ascent within a swath of warm air advection between
   850-700 mb. Forecast soundings from northeast MN show a gradual
   deepening of the dentritic growth zone in the coming hours with much
   of this layer residing within a favorable zone of lift.
   Additionally, transient frontogenesis may further augment and
   organize mesoscale ascent. The combined result will be the potential
   for at least a loosely organized snow band that will support
   moderate to heavy snowfall rates up to 1 inch/hour. With Lake
   Superior surface temperatures in the upper 30s/low 40s and
   east/southeast winds, lake-effect enhancement is likely along the
   North Shore where heavier snowfall rates are probable.

   ..Moore.. 12/28/2021

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

   ATTN...WFO...MQT...GRB...DLH...

   LAT...LON   45929216 46569336 47059405 47729413 48159370 48449288
               48339173 47969071 47439018 46668977 46298982 46019005
               45789052 45749124 45929216