Mesoscale Discussion 1852
   NWS Storm Prediction Center Norman OK
   0738 AM CST Wed Dec 16 2020

   Areas affected...eastern WV...northwest VA...western
   MD...south-central PA

   Concerning...Heavy snow 

   Valid 161338Z - 161915Z

   SUMMARY...Heavy snowfall rates ranging from 1 to 2.5 inches per hour
   are expected to begin over eastern WV and spread northeastward later
   this morning and into south-central PA by early afternoon.

   DISCUSSION...Radar mosaic shows an expanding precipitation shield
   across the central/southern Appalachians this morning.  Large-scale
   ascent will continue to increase through midday as a mid-level
   trough continues to approach the Mid-Atlantic states later
   today/tonight.  Models are in good agreement indicating the
   northwestern periphery of the heaviest precipitation rates to
   parallel the WV/VA border this morning, coincident with the
   development of stronger 850-700 mb frontogenetic forcing.  Forecast
   soundings show tropospheric profiles favoring snow as the
   precipitation type.  Furthermore, model guidance is indicating snow
   rates will likely exceed 1 inch per hour over eastern WV by late
   morning and increase further into the 1.5 to 2.5 inches per hour
   range by midday.

   ..Smith.. 12/16/2020

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

   ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...

   LAT...LON   39667722 38217902 38158000 38348030 38878024 40087838
               39667722