Storm Prediction Center Mesoscale Discussion 1

   Mesoscale Discussion 0001
   NWS Storm Prediction Center Norman OK
   0550 AM CST Thu Jan 02 2025

   Areas affected...South-central IA

   Concerning...Heavy snow 

   Valid 021150Z - 021445Z

   SUMMARY...A focused burst of moderate to heavy snow should continue
   to impact the I-80 corridor and overspread the I-35 corridor in the
   south-central Iowa vicinity through mid-morning. Rates near 1 inch
   per hour may occur within a narrow portion of the band into parts of
   the Des Moines Metro Area.

   DISCUSSION...Ahead of a low-amplitude shortwave impulse progressing
   across the Mid-MO Valley, a focused corridor of frontogenetic
   forcing for ascent has yield a comma-shaped snow band across parts
   of west-central to southwest IA. Multiple observations have reported
   1/4 to 1/2 mile visibility, albeit briefly, generally along and
   north of I-80. Early-morning guidance suggests frontogenesis will
   subside towards late morning, with recent HRRR runs indicating a
   loss of comma-head shape into more of a west/east-oriented band as
   this occurs. While snow rates around 1 in/hr should peak through
   15Z, more moderate snow rates near 0.5 in/hr may linger into midday.

   ..Grams.. 01/02/2025

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

   ATTN...WFO...DVN...DMX...

   LAT...LON   42059457 42159369 41989236 41659200 41209213 40919278
               40879394 41059479 41279498 41729475 42059457