Mesoscale Discussion 0058
   NWS Storm Prediction Center Norman OK
   0547 PM CST Fri Jan 12 2024

   Areas affected...Portions of northern/central Lower Michigan and far
   northeast Wisconsin

   Concerning...Heavy snow 

   Valid 122347Z - 130345Z

   SUMMARY...Heavy snow with rates of 1 to locally 2 in/hr will
   continue spreading northward across Lower MI and northeast WI this
   evening.

   DISCUSSION...A fairly expansive swath of heavy snow with rates near
   1 in/hr are ongoing across much of Lower MI this evening, largely
   driven by a deep band of isentropic ascent ahead of a 984 mb surface
   cyclone currently over northeast IL. Latest web cams across Lower MI
   show snow sticking to roadways as surface temperatures continue to
   nocturnally cool. Over the next few hours, the strong isentropic
   ascent (50-60-kt 1-2 km cross-isotherm flow per regional VWP) will
   continue northward in tandem with the northeastward-moving surface
   cyclone. This will occur as ascent in the left exit region of a
   robust southwesterly jet streak overspreads the area.

   The strengthening deep-layer ascent coupled with increasingly cold
   thermodynamic profiles with northward extent will continue to
   support heavy snow with rates of 1-2 in/hr given a deep/saturated
   dendritic growth zone. The best chance for localized 2 in/hr rates
   could develop across northeastern Lower MI from 00-04Z, where colder
   temperatures and stronger ascent should overlap for a couple hours
   (supported by the latest high-resolution guidance). In addition, a
   modest pressure gradient and related breezy surface winds should
   continue to favor visibility reductions to 0.25 miles in the heavier
   bursts of snow.

   ..Weinman.. 01/12/2024

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

   ATTN...WFO...DTX...APX...GRR...MQT...GRB...MKX...

   LAT...LON   42828544 43098686 43428775 43928809 44788799 45568719
               45918639 45978545 45868442 45598376 45088307 44198258
               43668248 43008299 42778397 42828544