Mesoscale Discussion 1755
   NWS Storm Prediction Center Norman OK
   0117 AM CDT Mon Oct 26 2020

   Areas affected...Far East-Central NM...Much of the TX
   Panhandle...Western OK/Eastern OK Panhandle

   Concerning...Winter mixed precipitation 

   Valid 260617Z - 261015Z

   SUMMARY...Mixed winter precipitation, predominantly sleet, is
   expected this morning from far east-central NM across the TX
   Panhandle into western OK.

   DISCUSSION...Regional radar imagery has shown an increase in
   precipitation coverage during the past few hours as isentropic
   ascent persists across the southern Plains/southern High Plains. 00Z
   AMA sounding sampled a shallow cold layer well, revealing a cold
   layer extending to 850 mb (about 1 km deep). Above this cold layer,
   warm temperatures associated with the persistent southwesterly flow
   aloft resulted in a strong inversion, with 700 mb temperatures near
   7 to 8 deg C. This results in a thermodynamic profile supporting
   mixed precipitation, predominantly sleet, once the mid-level layer
   moistens enough to erode the dry layer in place. The increase in
   precipitation coverage noted in regional radars is likely evidence
   of that ongoing moistening process, which is expected to continue
   and will soon support precipitation reaching the surface over much
   of this region. 

   Given the anticipated persistence of the southwesterly flow aloft
   and resulting maintenance of the warm layer aloft, the expectation
   is for an area of mixed winter precipitation to develop from far
   east-central NM across the TX Panhandle in western OK/eastern OK
   Panhandle. Sleet is expected to be the dominant precipitation type.
   Additionally, elevated instability, based the at the top of the warm
   layer around 700 mb, could contribute to higher precipitation rates
   as well as occasional lightning. Current observations show lightning
   within the precipitation band from Potter County TX into Harper
   County OK.

   ..Mosier.. 10/26/2020

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

   ATTN...WFO...OUN...DDC...LUB...AMA...ABQ...

   LAT...LON   35500332 36190236 37200002 36959882 36039911 35399962
               34630075 34150235 34130337 34390375 34850375 35500332