Mesoscale Discussion 1754
   NWS Storm Prediction Center Norman OK
   0617 PM CDT Sun Oct 25 2020

   Areas affected...West-central to south-central CO

   Concerning...Heavy snow 

   Valid 252317Z - 260315Z

   SUMMARY...Heavy snow that has affected portions of the Upper CO
   Valley along the I-70 corridor should shift south and may subside,
   while a separate band of heavy snow likely forms across portions of
   the Upper AR Valley, including the I-25 corridor near Pueblo.
   Snowfall rates of 2-3 inches/hour are expected in the stronger
   bursts.

   DISCUSSION...Intense frontogenetic forcing for ascent associated
   with a very tight thermal gradient arcing in a zigzag pattern across
   west-central to south-central CO has supported a persistent band of
   heavy snow just to the cold side of the slowly-southward shifting
   surface front. This band of heavy snow has recently affected the
   I-70 corridor in the Upper CO Valley. Radar/satellite imagery
   suggest a separate band of probable heavy snow is beginning to form
   off the northern Sangre de Cristos as elevated convection with CG
   lightning that formed farther west-southwest overspreads this
   portion of the baroclinic zone. Both convection allowing and
   parameterized guidance are largely consistent in suggesting that
   this will be the favored corridor for persistent heavy snow through
   the evening. Rates should reach 2-3 inches/hour in the stronger
   convective bursts that affect lower terrain across the Upper AR
   Valley across portions of I-25 from near Pueblo to Trinidad.

   ..Grams.. 10/25/2020

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

   ATTN...WFO...PUB...BOU...GJT...

   LAT...LON   38590514 38560478 38530422 38280413 37790414 37240433
               37090476 37500510 37910555 38090613 38370654 38500702
               38430785 38520834 38710861 39130865 39390814 39560775
               39560713 39580659 38700555 38590514