Mesoscale Discussion 1844
   NWS Storm Prediction Center Norman OK
   1200 PM CST Sun Dec 13 2020

   Areas affected...North-central to northeast Oklahoma

   Concerning...Heavy snow 

   Valid 131800Z - 132200Z

   SUMMARY...Lingering disorganized snow bands may bring periods of
   moderate snow for central/north-central Oklahoma early this
   afternoon, but locations further east/northeast will continue to see
   the potential for moderate to heavy snowfall rates through the late
   afternoon.

   DISCUSSION...Radar imagery from KTLX over the past hour has shown
   transient and disorganized snow bands developing from west of the
   OKC metro northeastward into the Tulsa, OK region. These bands are
   largely being driven by a broad swath of isentropic ascent at 850 mb
   combined with more focused regions of ascent within the deformation
   zone in and around the 850 mb layer. One such disorganized band is
   noted across southwest OK into north-central OK. Periodic visibility
   reductions down to one-half mile under this loose band suggest that
   periods of moderate snowfall may continue for the near term.
   However, as the upper-level trough continues to translate
   east/southeast, broad scale ascent at and above 700 mb will continue
   to shift into eastern OK and northwest AR. This departure of
   stronger forcing, along with the intrusion of mid-level dry air per
   recent water-vapor imagery, will likely limit the potential for
   widespread and persistent moderate to heavy snow for western and
   central OK for the remainder of the day.  

   Further northeast towards the Tulsa area where temperatures are at
   or just above freezing, the overlap of mid and upper-level forcing
   for ascent is more favorable for supporting organized and persistent
   snow banding. As such, areas of moderate to heavy snowfall rates
   should persist into the mid, and perhaps late, afternoon hours.

   ..Moore.. 12/13/2020

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

   ATTN...WFO...SGF...TSA...ICT...OUN...

   LAT...LON   36969762 37049612 37339502 37169421 36399394 35889406
               35759467 35639531 35509587 35479660 35449727 35449747
               35609779 36149790 36649778 36969762