Storm Prediction Center Mesoscale Discussion 284

   Mesoscale Discussion 0284
   NWS Storm Prediction Center Norman OK
   0409 PM CDT Sat Mar 29 2025

   Areas affected...Northeast WI into southern upper MI and northern
   lower MI

   Concerning...Freezing rain 

   Valid 292109Z - 300115Z

   SUMMARY...An increase in freezing rain rates is possible into the
   evening.

   DISCUSSION...Some increase in precipitation has been noted this
   afternoon from northeast WI into northern lower MI, in advance of a
   low-amplitude midlevel shortwave trough moving into western WI.
   Modest isentropic ascent will continue to support light to moderate
   precipitation in an west-east band across the region into the
   evening, with some tendency for northward expansion with time. 

   The influence of a cold surface ridge over parts of Ontario/Quebec
   will maintain cold surface temperatures into the evening, while
   modest warm advection continues aloft. This should generally
   maintain a favorable thermodynamic profile for freezing rain, though
   some mixing with sleet will be possible. Ice accretion rates could
   occasionally exceed 0.03 inches per hour, as noted in recent METAR
   observations from Alpena (KAPN). Another wave of moderate to locally
   heavy precipitation could approach western and northern parts of the
   MCD area late tonight.

   ..Dean.. 03/29/2025

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

   ATTN...WFO...APX...MQT...GRB...

   LAT...LON   45918798 45998565 45578315 44898275 44478289 44398360
               44898630 44608806 44618980 44878967 45688920 45918798