Mesoscale Discussion 0148
   NWS Storm Prediction Center Norman OK
   0640 PM CST Fri Feb 16 2024

   Areas affected...The Upper Ohio River Valley into the central
   Appalachians

   Concerning...Heavy snow 

   Valid 170040Z - 170445Z

   SUMMARY...A swath of moderate to heavy snow is expected to spread
   east across the upper Ohio River Valley into the central
   Appalachians through the evening hours.

   DISCUSSION...Over the past several hours, a semi-persistent band of
   moderate to heavy snow has shifted east across the Midwest and
   middle OH River Valley. Surface observations and web cams under this
   band have shown visibility reductions down to 1/4 mile at times,
   indicative of moderate to heavy snowfall rates. Snowfall reports
   over the past 1-3 hours support this idea with multiple reports of
   3-5 inch snowfall totals since early afternoon. Recent upper-air
   analyses continue to show favorable overlap of broad synoptic ascent
   ahead of the approaching low-amplitude upper wave with a more
   focused zone of mesoscale ascent driven by a plume of warm advection
   and frontogenesis within the 925-850 mb layer. Favorable phasing of
   these mechanisms is expected to persist for the next several as the
   synoptic system shifts east towards the Mid-Atlantic. 

   Consequently, organized snow bands capable of heavy snowfall rates
   upwards of 1-2 inch/hour will remain possible across the upper OH
   River Valley into the central Appalachian region for the next
   several hours. Locations downstream that are currently not below
   freezing may see a slightly delayed onset of snowfall as low-level
   saturation promotes temperature reductions below freezing.
   Furthermore, orographic ascent within the Appalachians may augment
   lift over eastern WV/western VA and increase the potential for 2+
   inch/hour snowfall rates during the 04-06 UTC period.

   ..Moore.. 02/17/2024

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

   ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...JKL...ILN...
   LMK...

   LAT...LON   39078529 40128346 40368289 40838105 40987996 40967914
               40867850 40627792 40337768 40067754 39707765 39477780
               38457893 38267929 38127958 38077995 38098052 38438436
               38468482 38538512 38638531 38848542 39078529